.Net Material

Dependency Injection

2012-02-07T21:52:00.000-08:00

Replace dependencies with Dependency Injection to make your classes easier to reuse and test.

The dependency injection pattern, is one of the most popular design paradigms today. It facilitates the design and implementation of loosely coupled, reusable, and testable objects in your software designs by removing dependencies that often inhibit reuse. Dependency injection can help you design your applications so that the architecture links the components rather than the components linking themselves.

Samples used for this presentation: DI_Demo.zip

WCF Bindings - Overview

2012-01-22T20:25:00.000-08:00

Calling a Static Page Method using jQuery

2012-01-20T06:23:00.000-08:00

If you do not plan to call a web method from multiple pages, don’t perform all the work of creating a separate web service. Instead, you can expose a static method from the same AJAX page calling the web method.

1..ASPX Page -

DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<title>Show Web Service Methodtitle>

$(document).ready(function () {

$("#btnGet").click(function () {

$.ajax({

type: "POST",

dataType: "json",

contentType: "application/json",

url: "ShowPageMethod.aspx/GetQuote",

success: function (data) {

$("#spanQuote").html(data.d);

error: function () {

alert("The call to the web service failed.");

}

})

});

script>

head>

<body>

<div>

<br />

div>

form>

body>

html>

2. Code Behind Code (.ASPX.CS)

Add this method

[System.Web.Services.WebMethod]

public static string GetQuote()

{

List<string> quotes = new List<string>();

quotes.Add("The fool who is silent passes for wise.");

quotes.Add("The early bird catches the worm.");

quotes.Add("If wishes were true, shepherds would be kings.");

Random rnd = new Random();

return quotes[rnd.Next(quotes.Count)];

}

Calling Web Services from the Client using jQuery

2012-01-20T06:17:00.000-08:00

1. .ASMX page - Web Service Code:

[WebService(Namespace = http://tempuri.org/)]

[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]

[System.ComponentModel.ToolboxItem(false)]

// To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line.

[System.Web.Script.Services.ScriptService]

public class QuotationService : System.Web.Services.WebService

{

[WebMethod]

public string GetQuote()

{

List<string> quotes = new List<string>();

quotes.Add("The fool who is silent passes for wise.");

quotes.Add("The early bird catches the worm.");

quotes.Add("If wishes were true, shepherds would be kings.");

Random rnd = new Random();

return quotes[rnd.Next(quotes.Count)];

}

2. .ASPX Page - Calling web service using jQuery

DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<title>Show Web Service Methodtitle>

$(document).ready(function () {

$("#btnGet").click(function () {

$.ajax({//makes an asynchronous call to a URL.

type: "POST",

dataType: "json",

contentType: "application/json",

url: "QuotationService.asmx/GetQuote",

success: function (data) {

$("#spanQuote").html(data.d);

error: function () {

alert("The call to the web service failed.");

}

})

});

script>

head>

<body>

<div>

<br />

div>

form>

body>

html>

What Is jQuery?

2012-01-20T06:06:00.000-08:00

jQuery is an extremely fast, lightweight JavaScript library that simplifies many aspects of client-side web development.You can use jQuery for almost any client-side functionality that you can think of—event handling,animations, drag-and-drop functionality, asynchronousweb service calls, and much more. Furthermore, jQuery supports a robust plug-in modelthat enables developers to write their own extensions to implement whatever functionality
they want.

There are already hundreds of powerful jQuery plug-ins available. jQuery is CSS3-compliant and works on almost all browsers—Internet Explorer 6.0+, FireFox 2+, Safari 3.0+, Opera 9.0, and Google Chrome. This means that you can write one set of code and not have to worry about handling the specifics of different browser implementations; each line of jQuery works exactly the same on all browsers.The jQuery library is used on an incredible number of popular websites. Google, Dell,
Bank of America, Digg.com, Netflix, WordPress, and even the White House are some examples of websites that rely on jQuery for client-side functionality.

WCF (Windows Communication Foundation)

2011-01-23T23:17:00.000-08:00

What is WCF?

WCF is service oriented technology. Using WCF framework, we can build the service oriented architecture.
WCF is unification of .NET framework communication technologies like MSMQ, Remoting, Web Services and COM+.

Fiserv Interview Questions.

2009-11-07T03:43:00.001-08:00

1) For edit functionality in DataGird specify Column name
2) Why you may not want to use Paging funtionality in data grid
3) Function of SqlCommanBuilder in code.
4) Find the error in code . Its related to database connection. I think that connection sould be closed in finally instead of try.
5) What is the relation between src='' & Inherits='' in <@ Page > directive
6) What is derective in the user control page & its extention of file
7) Question related to 404 error code Error page & Default error page.
8) Its related to Autherization in web config related to folders
9) Related to definition
10) not remembred with question but answer is cookiless = true related question
11) Page is posting the 2 times why is it so 1) user control load 2) some control call load
12) describe !Page.PostBack Select Options
13) Question related to Session mode = SQLServer
14) Some question related to validation control - compare validator
15) Some question related to page inheritance - I think answer is - page
16) One question related to Asp.net 1.1 -- Is the mobile application will work in asp.net 1.1
17) question related to ASP.NET AdRotator Control - what is tag - A number that indicates the importance of the ad in the schedule of rotation relative to the other ads in the file (optional).

The larger the number, the more often the ad is displayed. The total of all Impressions values in the XML file cannot exceed 2,047,999,999. If it does, the AdRotator throws a run-time exception.

dont send me reply

18) Some question related to - error related to - input id="Button1" onserverclick="check" runat="server" type="button" value="button" /> & onserverclick

19) In repeter control they want to show title -- <%#Container.DataItem("title")%> OR <%# DataBinder.Eval(Container.DataItem,"CustomerName") %> Or ...
20) Related to DataList -- Value & Text Showing Its simple.
21) when the Viewsate is avilable in life cycle - answer is after LOAD
22) Simple c# code answer is 1
23) What are the Session-State Modes ? ans - InPro,StateServer,SQLServer
24)

Send Email in asp.net

2009-10-05T09:51:00.000-07:00

add System.Net.Mail; namespace
///*********************************************************************************
///

///To Send the simple Email
///

    ///
From Email Id
    /// To Email Id
    /// Email Subject
    /// Email Body
    /// Returns bool with Indication
    ///*********************************************************************************
    public bool SendEMail(string FromAddressId, string ToAddressId,
                          string Subject, string MessageBody)
    {
        SmtpClient objSmtpClient = new SmtpClient();
        MailMessage message = new MailMessage();

        try
        {
            MailAddress fromAddress = new MailAddress(FromAddressId);
            objSmtpClient.Host = SmtpServerName;
            objSmtpClient.Port = SmtpServerPortNo;
            message.From = fromAddress;
            message.To.Add(ToAddressId);
            message.Subject = Subject;
            message.IsBodyHtml = true;
            message.Body = MessageBody;
            objSmtpClient.Send(message);
            return true;
        }
        catch (Exception ex)
        {
            throw ex;
        }
        finally
        {
            objSmtpClient = null;
            message = null;
        }
    } // End Of Sendmail Function

Creating Error log

2009-10-05T09:42:00.000-07:00

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;
using CommonComponents;
using System.IO;

///

/// Summary description for clsErrorLog
///

public class clsErrorLog
{
    /*************************************************************
    NAME:          WriteToErrorLog
    PURPOSE:       Open or create an error log and submit error message
    PARAMETERS:    ex - object of Exception class
                   ErrorTitle - title of the error
                   ErrorClass - name of form or class in which error occured
                   ErrorMethod - name of the method in which error occured
    RETURNS:       Nothing
    '*************************************************************/
    ///

/// Open or create an error log and submit error message. Returns void
///

    ///
object of Exception class
    /// title of the error
    /// name of form or class in which error occured
    /// name of the method in which error occured
    ///
    public static void WriteToErrorLog(Exception ex, string ErrorTitle, string ErrorClass, string ErrorMethod)
    {
        /* check and make the directory if necessary; this is set to look in
           the application folder, you may wish to place the error log in
           another location depending upon the user's role and write access to
           different areas of the file system */
        string strPath = HttpContext.Current.Server.MapPath("~\\Errors");
        //if (!Directory.Exists(strPath))
        //    Directory.CreateDirectory(strPath);
        DirectoryInfo objDirInfor = new DirectoryInfo(strPath);
        if (!objDirInfor.Exists)
            objDirInfor.Create();
        //check the file
        FileStream fs = new FileStream(strPath + "\\MilesSelfTestWebErrorlog.txt", FileMode.OpenOrCreate, FileAccess.ReadWrite);
        StreamWriter s = new StreamWriter(fs);
        s.Close();
        fs.Close();
        //log it
        FileStream fs1 = new FileStream(strPath + "\\MilesSelfTestWebErrorlog.txt", FileMode.Append, FileAccess.Write);
        StreamWriter s1 = new StreamWriter(fs1);
        System.Text.StringBuilder strErrorDesc = new System.Text.StringBuilder("");
        strErrorDesc.AppendLine("Title: " + ErrorTitle + Environment.NewLine);
        strErrorDesc.AppendLine("ErrorClass: " + ErrorClass + Environment.NewLine);
        strErrorDesc.AppendLine("ErrorMethod: " + ErrorMethod + Environment.NewLine);
        strErrorDesc.AppendLine("Message: " + ex.Message + Environment.NewLine);
        strErrorDesc.AppendLine("StackTrace: " + ex.StackTrace + Environment.NewLine);
        strErrorDesc.AppendLine("Date/Time: " + DateTime.Now.ToString() + Environment.NewLine);
        strErrorDesc.AppendLine("================================================" + Environment.NewLine);
        s1.Write(strErrorDesc.ToString());
        s1.Close();
        fs1.Close();
        //clsEmail objSimpleEmail = new clsEmail();
        //objSimpleEmail.SendEMail("admin@nigeriaexamsonline.com", "bhaveshp@iprogrammer.co.in, milindm@iprogrammer.co.in", ErrorTitle, strErrorDesc.ToString());
        //objSimpleEmail = null;
    }
}

Finding Nth Highest Salary Query

2009-09-16T00:17:00.000-07:00

SELECT max(sal) FROM tbltemp WHERE sal NOT IN
(SELECT distinct top 2 sal FROM tbltemp ORDER BY sal desc)

for eg. for 3rd highest top will be 3-1 =2 (top 2) therefore top N-1

Or

SELECT TOP 1 sal

FROM (

   SELECT DISTINCT TOP 2 sal
   FROM tbltemp
   ORDER BY sal DESC
   ) A
ORDER BY sal

Adding Custom Tags in Web.config

2009-09-14T00:31:00.000-07:00

To add cutom tag in your web config its a simple process. I will expain it step by step

Add Following to your web config

Remember you have to add information about your System assembly which you can find in your GAC (Global assembly cache) Path: "C:\WINDOWS\assembly" right click on System assembly and you will get Property about it.

Then to get those custom tag values write the following code on default.aspx.cs file

protected void Page_Load(object sender, EventArgs e)
{
NameValueCollection Col = new NameValueCollection();
Col = (NameValueCollection)System.Configuration.ConfigurationManager.GetSection("MyCustomSection");
        for (int i = 0; i < c1.Keys.Count; i++)
        {
           Response.Write(String.Format("Key = {0}, Value = {1} ", c1.Keys[i], c1[i].ToString()));
        }
}

Singleton Design Pattern

2009-09-09T19:39:00.000-07:00

one of the good explanation found in ASP.NET 3.5 Application Architecture Design

public sealed class EmailManager

{

private static EmailManager _manager;

//Private constructor so that objects cannot be created

private EmailManager()

{

}

public static EmailManager GetInstance()

{

// Use 'Lazy initialization'

if (_manager == null)

{

//ensure thread safety using locks

lock(typeof(EmailManager)

{

_manager = new EmailManager();

}

return _manager;

}

let us understand the code step-by-step:

1. public sealed class EmailManager: We have used the sealed keyword to make our EmailManager class uninheritable. This is not necessary, but there is no use having derived classes as there can be only one instance of this class in memory. Having derived class objects will let us create two or more instances which will be against the singleton's design objective.

2. private static EmailManager _manager:Next, we create a variable named _manager, which holds a reference to the single instance of our EmailManager class. We have used a static modifier because we will be accessing this variable from a static method—GetEmailManager(), and static methods can use only static variables.
private EmailManager()
{
}
We need to create a private constructor to make sure that we don't accidentally initialize an object of the GetEmailManager class. By only initializing via the static GetInstance() method, we should get a single instance of this class.
3. public static EmailManager GetInstance()
{
// Use 'Lazy initialization'
if (_manager == null)
{
//ensure thread safety using locks
lock(typeof(EmailManager)
{
_manager = new EmailManager();
}
}
return _manager;
}
GetInstance() is the static method that we will use from outside this code to get the current reference of the EmailManager class. In this method, we are using the lazy loading technique to load the instance on demand. We first check if the current instance is null or not. If it is null, then we create a new one; otherwise we return the existing
static instance.
lock(typeof(EmailManager)

4. The private _manager object, marked static, is used inside a critical section (using lock) to make sure it is thread safe. Thread safety is very important here. Otherwise, two threads might simultaneously call GetInstance() and, on finding the EmailManager instance (_manager) null, will both try to create an instance, thereby creating two instances of the class. The lock keyword helps us make sure that once a thread enters the region, no other thread can do so until the first thread exits, making our code thread safe. We pass the EmailManager's type in order to lock the statement using the typeof operator to define the scope of the lock statement.
An important point to note is that in the above code we have to make sure that the
type used in the typeof() command is not publicly accessible, otherwise the scope
would be affected. It is better to create a private object within our class to use as a
reference object in the lock statement, as in:
private static object forLock = new object();
public static EmailManager GetInstance()
{
// Use 'Lazy initialization'
if (_manager == null)
{
//ensure thread safety using locks
lock(typeof(forLock)
{
_manager = new EmailManager();
}
}
return _manager;
}
So the above code can be used for implementing a Singleton design pattern in

ASP.NET effectively and safely.

SOAP Header (credentials) for cosuming web service

2009-09-07T03:12:00.000-07:00

Its the optional part of SOAP Message. Instead including meta data (Credentials) in your web signature you can use SOAP header to consume web service.

// SOAP Header class

public class HelloHeader : SoapHeader
{
    public string Username;
    public string Password;
}

    public HelloHeader myHeader;
    [WebMethod]
    [SoapHeader("myHeader")]
    public string HelloWorld()
    {
        if (myHeader == null)
        {
            return "Hello World";
        }
        else
        {
            return "Hello " + myHeader.Username + ". " +
            "
Your password is: " + myHeader.Password;
        }
    }

// Consuming this web service
localhost.HelloHeader objHEader = new WindowsApplication1.localhost.HelloHeader();
localhost.HelloSoapHeader objService = new WindowsApplication1.localhost.HelloSoapHeader();
objHEader.Username = "milind";
objHEader.Password = "mahajan";
objService.HelloHeaderValue = objHEader;
MessageBox.Show( objService.HelloWorld());

Metod overloading in web serive

2009-09-07T02:52:00.000-07:00

To overload web methods you have to use MessageName attribute otherwise you will get error.

[WebMethod(MessageName = "Hello")]
public string Hello()
{
return "Hello";
}

[WebMethod(MessageName = "HelloWithFirstName")]
public string Hello(string FirstName)
{
return "Hello " + FirstName;
}

Web serice to upload image on server

2009-09-07T02:29:00.001-07:00

/// web service
/// Upload image on server with the .jpg, .ico, .gif, .bmp, .png formats.
/// Size should be less than 80kb
///
/// /// ///
[WebMethod]
public string UploadImage(byte[] ImgIn, string FileName)
{
MemoryStream ms = null;
Bitmap b = null;
try
{
ms = new MemoryStream(ImgIn);
if (ms.Length <= 80000) // 80kb limit for image to upload
{
b = (Bitmap)Image.FromStream(ms);
if (FileName.ToLower().Contains(".jpeg") || FileName.ToLower().Contains(".jpg"))
b.Save("C:\\" + FileName, System.Drawing.Imaging.ImageFormat.Jpeg);
if (FileName.ToLower().Contains(".gif"))
b.Save("C:\\" + FileName, System.Drawing.Imaging.ImageFormat.Gif);
if (FileName.ToLower().Contains(".bmp"))
b.Save("C:\\" + FileName, System.Drawing.Imaging.ImageFormat.Bmp);
if (FileName.ToLower().Contains(".png"))
b.Save("C:\\" + FileName, System.Drawing.Imaging.ImageFormat.Png);
if (FileName.ToLower().Contains(".ico"))
b.Save("C:\\" + FileName, System.Drawing.Imaging.ImageFormat.Icon);
return "Uploaded successfully.";
}
else
return "Image size should be less than 80kb.";
}
catch (Exception ex)
{
return "Some error occurred, please try again later.";
}
finally
{
if (ms != null)
ms.Dispose();
if (b != null)
b.Dispose();
}
}

// Consuming the web service

localhost.ImageUpload obj = new localhost.ImageUpload();
FileStream fs = new FileStream(FileUpload1.PostedFile.FileName, FileMode.OpenOrCreate, FileAccess.Read);
Byte[] img = new Byte[fs.Length];
fs.Read(img, 0, Convert.ToInt32(fs.Length));
lblMsg.Text = obj.UploadImage(img, FileUpload1.FileName);

Nullable in c#

2009-09-02T05:04:00.000-07:00

Nullable types can represent all the values of an underlying type, and an additional null value. Nullable types are declared in one of two ways:
        System.Nullable variable
        -or-
        T? variable
Any value type may be used as the basis for a nullable type

class Program
    {
        static void Main(string[] args)
        {
            int? x = 10;
            if (x.HasValue)
            {
                System.Console.WriteLine(x.Value);
            }
            else
            {
                System.Console.WriteLine("Undefined");
            }

            Console.ReadKey();

            int? y = null;
            if (y != null)
            {
                System.Console.WriteLine(y.Value);
            }
            else
            {
                System.Console.WriteLine("Undefined");
            }

            Console.ReadKey();

            int? n = 5;

            //int m1 = n;      // Will not compile.
            int m2 = (int)n;   // Compiles, but will create an exception if n is null.
            int m3 = n.Value; // Compiles, but will create an exception if n is null.

            Console.ReadKey();
            int A = 0;
            System.Console.WriteLine("A++ = {0}", A++);
            A = A + 1;
            System.Console.WriteLine("A = A + 1 {0}", A);
            System.Console.WriteLine("++A {0}", ++A);
            Console.ReadKey();

        }
    }

Explicit keyword in c#

2009-09-02T04:58:00.001-07:00

The explicit keyword is used to declare an explicit user-defined type conversion operator

class Celsius
    {
        public Celsius(float temp)
        {
            degrees = temp;
        }
// define explicit Celsius-to-Fahrenheit conversion operator:
        public static explicit operator Fahrenheit(Celsius c)
        {
            return new Fahrenheit((9.0f / 5.0f) * c.degrees + 32);
        }
        public float Degrees
        {
            get { return degrees; }
        }
        private float degrees;
    }

    class Fahrenheit
    {
        public Fahrenheit(float temp)
        {
            degrees = temp;
        }
// define explicit Fahrenheit-to-Celsius conversion operator:
        public static explicit operator Celsius(Fahrenheit f)
        {
            return new Celsius((5.0f / 9.0f) * (f.degrees - 32));
        }
        public float Degrees
        {
            get { return degrees; }
        }
        private float degrees;
    }

static void Main(string[] args)
        {
                Fahrenheit f = new Fahrenheit(100.0f);
                Console.Write("{0} fahrenheit", f.Degrees);
                Celsius c = (Celsius)f;// explicit conversion
                Console.Write(" = {0} celsius", c.Degrees);
                Fahrenheit f2 = (Fahrenheit)c;// explicit conversion
                Console.WriteLine(" = {0} fahrenheit", f2.Degrees);
        }

Cursor in sql server

2009-09-01T06:43:00.000-07:00

-To fetch row by row data

Declare Cursor
Open
Fetch first time
fetch data until @@Fetch_Status = 0
Close
Deallocate

Disadvantage: - Time Consuming - required lot of resources & temporary storage.

View in sql server

2009-09-01T06:37:00.000-07:00

Referred as "Virtual Table" Can not store data (except for indexed views) rather than only referto data present in table. e.g. Create View vwsample [optional] With Encryption OR With Schemabinding [/optional] AS Select Cid, CName FRom Customer GO With Encryption - You can see view query (its encrypted) With Schemabinding - You are not able to alter table on which it's created.

Assembly in .net

2009-09-01T06:18:00.000-07:00

-It is the fundamental building block of .net framework -basic unit of deployment or versioning (.exe or .dll) -Consisting

Manifest
Metadata
IL Code
Resources

1) Manifest- Describe assembly itself Contents

Assembly Name
Version number
Culture
Strong name information
List of files
Type reference information
Information on reference assemblies

2) Metdata- Describe Contents within assembly like Classes, Namespaces, Interfaces, Scope, Properties, Methods & their parameteres. 3) IL Code- The compilers translates your code into Microsoft intermediate language (MSIL). The common language runtime includes a JIT compiler for converting this MSIL then to native code. 4) Resources- are the files like image files

Command Object's Method

2009-09-01T05:20:00.000-07:00

objects exposes methods for executing commands based on the type of command and desired return value 1) ExecuteNonQuery: Executes a command that does not return any rows. 2) ExecuteReader: Returns a DataReader object. 3) ExecuteRow: Return sql record (return one datbase record) 4) ExecuteScalar: Returns a single scalar value. 5) ExecuteXMLReader: Returns an XmlReader. Available for a SqlCommand object only.

Triggers in sql server

2009-09-01T02:37:00.000-07:00

Definition: Are special type of stored procedure that are defined to execute automatically, In place of or after data modification when Insert, Update, Delete triggering actions occurred on that table. 1) After Trigger Fired the triggering action. Executed automatically before the transaction is committed or rolled back. e.g. CREATE TRIGGER trgCheckStock ON [products] FOR UPDATE AS IF( Select inStockFrom inserted) < 0) BEGIN PRINT 'Can not oversell products' PRINT 'Transaction has been canceled' END GO 2) Instead Of Trigger Fire in place of the triggering action. Executed automatically before primary key and foreign key constraints are checked. e.g. CREATE TRIGGER trgCantDelete ON table1 INSTEAD OF DELETE AS PRINT 'you cannot delete this data' GO

Resume

2009-09-01T02:36:00.000-07:00

Latest Resume - Upload a Document to Scribd

Differance between Value Type and Referance Type

2009-09-01T02:25:00.000-07:00

Value Type: 1) Stored in stack. 2) Access directly. 3) Life time determine by lifetime of variable that contain them. 4) e.g. All numeric data type, Boolean, char, Date, Structure, enumerations. Reference Type: 1) Stored in heap. 2) Access through references. 3) Lifetime is managed by .net framework. 4) e.g. All arrays, String, Class types, Delegate. Note: Object is not any kind of type. You can create object of structure as well as Class Are not type: Namespaces, Modules, Events, properties, procedures, variables, constants ,& fields.

Differance between Dataset and Datareader

2009-09-01T02:09:00.000-07:00

Dataset 1) Read/write access to data. 2) Disconnected architecture. 3) Include multiple table from different database. 4) Bind to multiple controls. 5) forward and backward scanning of data. 6) supported by visual studio .net tool. 7) you can set relation between tables. DataReader 1) Read only 2) Connected architecture. 3) Include 1 table from 1 database only. 4) Bind to one control only. 5) fast forward only. 6) Manually coded. 7) No relations.

Differance between Strucutre and Class

2009-09-01T02:03:00.000-07:00

Structure: 1) Value type stored in stack. 2) Inheritance is not possible in structure. 3) do not require constructor. 4) objects are not terminated by GC. 5) members can not be protected. Class: 1) Reference type stored in heap. 2) Inheritance is possible. 3) Contain constructor. 4) object is terminated by GC. 3) Member can be any type.

Differeance between Interface and Abstract Class

2009-09-01T01:15:00.000-07:00

Interface: 1) Define a Contract. 2) can inherit only interfaces. 3) don't have constructor and distructor. 4) don't have concrete methods. 5) Inheritable by Structure. 6) Multiple inheritance is possible using Interface. 7) All members are Public by default. Abstract Class: 1) Can't be initiated, partially implemented. 2) Can inherit classes & Interfaces. 3) Can have Constructor & Distructor. 4) Some methods can be concrete. 5) Not inheritable by structure. 6) Multiple inheritance not possible. 7) Members can have many modifiers.

Differance between Overloading and Overriding

2009-09-01T01:10:00.000-07:00

Overloading: 1) Same name in same/derived class but with different/type of parameter. 2) Compiletime polymorphism. 3) Having Different signature. Overriding: 1) we need to provide different implementation than base class. 2) Runtime Polymorphism. 3) Having same signature.

Differance between Const and Readonly

2009-09-01T01:01:00.000-07:00

Const 1) Value evaluated at compile time 2) can't be static. 3) Initialize at declaration only. e.g. const int a = 100 Readonly 1) Value evaluated at runtime. 2) Can be static. 3) can initialize at declaration or in constructor. e.g. public readonly int doc = 5; public program() { doc = 5; }

Differance between Truncate and Delete

2009-09-01T00:52:00.000-07:00

Truncate 1) Delete all rows. 2) Identity counter retain. 3) Don't make entry to transaction log. therefore it is faster. 4) DDL command. 5) can not rollback 6) do not activate trigger. Delete 1) Delete 1 or more row depend on where clause. 2) retain Identity counter. 3) Make entery to transaction log. so it is slower. 4) DML command. 5) Can be rollback. 6) Activate trigger.

Differance between Stored Procedure & User define functiona(UDF)

2009-08-28T05:53:00.000-07:00

Stored Procedure1) If error occurred then execute next statement.
2) Use EXECUTE or EXEC to run.3) Can return values not mandatory.
4) SP can not be called from UDF.
5) Have transaction.
6) Can use XML FROM Clause.

UDF1) If error occurred then can not execute next statement.
2) Execute from sql SELECT or SQL action queries.
3) Must return 1 Value or table.
4) UDF can be called from SP.
5) Don't have transaction because don't have DML queries.
6) Can't use XML FROM Clause.

ASP.NET AJAX Server Control

2009-08-24T03:16:00.000-07:00

1. ScriptManager: it takes care of loading the JavaScript libraries needed by ASP.NET AJAX. A component control that manages the marshalling of messages to the AJAX-enabled server for the parts of the page requiring partial updates. Every ASP.NET page will require a ScriptManager control in order to work. It is important to note that you can have only a single ScriptManager control on a page. 2. ScriptManagerProxy: Enables nested components such as content pages and user controls to add script and service references to pages when a ScriptManager control is already defined in a parent element. A component control that acts as a ScriptManager control for a content page. The ScriptManagerProxy control, which sits on the content page (or sub-page), works in conjunction with a required ScriptManager control that resides on the master page. 3. Timer: The Timer control performs postbacks at defined intervals. If you use the Timer control with an UpdatePanel control, you can enable partial-page updates at a defined interval. You can also use the Timer control to post the whole page.The Timer control will execute client-side events at specific intervals and allows specific parts of your page to update or refresh at these moments. 4. UpdatePanel: A container control that allows you to define specific areas of the page that are enabled to work with the ScriptManager. These areas can then, in turn, make the partial page postbacks and update themselves outside the normal ASP.NET page postback process. 5. UpdateProgress: A control that allows you to display a visual element to the end user to show that a partial-page postback is occurring to the part of the page making the update. This is an ideal control to use when you have long-running AJAX updates.

Hosting a WCF Service

2009-07-29T01:22:00.000-07:00

WCF is flexible because its services can be hosted in different types of applications. The following lists several common scenarios for hosting WCF services:

Self-hosting
Managed Windows Service
IIS (II6 and IIS7)
WAS

WCF contracts

2009-07-29T00:43:00.000-07:00

WCF contracts define the behavior of WCF services. They are created in code by service developers, and are exposed to clients in the service metadata. The five types of contracts:

Service Contracts
Operation Contracts
Data Contracts
Message Contracts
Fault Contracts

Slide 23

1.A service contract defines the operations that a service supports, and maps to a portType in Web Service Description Language (WSDL). Service contracts are implemented as .NET Framework interfaces that are annotated with the ServiceContract attribute. [ServiceContract] public interface IMyContract { ...} 2.Operation contracts define the individual operations that a service supports and map to operations in WSDL. Operations are defined by adding methods to a Service Contract interface that is annotated with the OperationContract attribute. [OperationContract] void SomeOperation(); 3.Data contracts define how complex types are serialized when they are used in WCF service operations. They are defined by applying the DataContract and DataMember attributes to classes. [DataContract] public class SomeType{ [DataMember] public int ID;} 4.Message contracts describe the entire SOAP message format. They can use data contracts and serializable types to emit schema for complex types, and they also make it possible to control the SOAP message headers and body explicitly, by using a single type. Message contracts provide a simple method to add custom SOAP headers to incoming and outgoing messages. [MessageContract] public class MyRequest { [MessageHeader] public string field1; [MessageBody] public string field2; } 5.A WCF service reports errors by using Fault objects. Fault contracts document the errors that WCF code is likely to produce, and WCF maps Fault objects to SOAP faults. Note that the type specified in the FaultContract does not have to be an exception, although it often will be. Example [DataContract] public class Eval { [DataMember] public string Id; [DataMember] public string Comments; [DataMember] public string Submitter; [DataMember] public DateTime TimeSubmitted; } [ServiceContract] public interface IEvalService { [OperationContract] void SubmitEval(Eval eval); [OperationContract] List GetEval(); [OperationContract] void RemoveEval(string id); } [ServiceBehavior(InstanceContextMode= InstanceContextMode.Single)] public class EvalService : IEvalService { #region IEvalService Members List evals = new List(); public void SubmitEval(Eval eval) { eval.Id = Guid.NewGuid().ToString(); evals.Add(eval); } public List GetEval() { return evals; } public void RemoveEval(string id) { evals.Remove(evals.Find(e => e.Id.Equals(id))); } #endregion }

Windows Communication Foundation is...

2009-07-28T04:39:00.000-07:00

Some Important points I have collected from MSDN site are: A part of the .NET Framework that provides a unified programming model for rapidly building service-oriented applications that communicate across the web and the enterprise. The global acceptance of Web services, which includes standard protocols for application-to-application communication, has changed software development. For example, the functions that Web services now provide include security, distributed transaction coordination, and reliable communication. The benefits of the changes in Web services should be reflected in the tools and technologies that developers use. Windows Communication Foundation (WCF) is designed to offer a manageable approach to distributed computing, broad interoperability, and direct support for service orientation. WCF simplifies development of connected applications through a new service-oriented programming model. WCF supports many styles of distributed application development by providing a layered architecture. At its base, the WCF channel architecture provides asynchronous, untyped message-passing primitives. Built on top of this base are protocol facilities for secure, reliable, transacted data exchange and broad choice of transport and encoding options. The typed programming model (called the service model) is designed to ease the development of distributed applications and to provide developers with expertise in ASP.NET Web services, .NET Framework remoting, and Enterprise Services, and who are coming to WCF with a familiar development experience. The service model features a straightforward mapping of Web services concepts to those of the .NET Framework common language runtime (CLR), including flexible and extensible mapping of messages to service implementations in languages such as Visual C# or Visual Basic. It includes serialization facilities that enable loose coupling and versioning, and it provides integration and interoperability with existing .NET Framework distributed systems technologies such as Message Queuing (MSMQ), COM+, ASP.NET Web services, Web Services Enhancements (WSE), and a number of other functions.

Most important aspects of WCF:

Unification of existing .NET Framework communication technologies.
Support for cross-vendor interoperability, including reliability, security, and transactions.
Explicit service orientation.

WCF Terms

Other concepts and terms used in the WCF documentation include the following.

message

A message is a self-contained unit of data that may consist of several parts, including a body and headers.

service

A service is a construct that exposes one or more endpoints, with each endpoint exposing one or more service operations.

endpoint

An endpoint is a construct at which messages are sent or received (or both). It comprises a location (an address) that defines where messages can be sent, a specification of the communication mechanism (a binding) that described how messages should be sent, and a definition for a set of messages that can be sent or received (or both) at that location (a service contract) that describes what message can be sent.

An WCF service is exposed to the world as a collection of endpoints.

application endpoint

An endpoint exposed by the application and that corresponds to a service contract implemented by the application.

infrastructure endpoint

An endpoint that is exposed by the infrastructure to facilitate functionality that is needed or provided by the service that does not relate to a service contract. For example, a service might have an infrastructure endpoint that provides metadata information.

address

An address specifies the location where messages are received. It is specified as a Uniform Resource Identifier (URI). The URI schema part names the transport mechanism to use to reach the address, such as HTTP and TCP. The hierarchical part of the URI contains a unique location whose format is dependent on the transport mechanism.

The endpoint address enables you to create unique endpoint addresses for each endpoint in a service, or under certain conditions share an address across endpoints. The following example shows an address using the HTTPS protocol with a non-default port:

HTTPS://cohowinery:8005/ServiceModelSamples/CalculatorService

binding

A binding defines how an endpoint communicates to the world. It is constructed of a set of components called binding elements that "stack" one on top of the other to create the communication infrastructure. At the very least, a binding defines the transport (such as HTTP or TCP) and the encoding being used (such as text or binary). A binding can contain binding elements that specify details like the security mechanisms used to secure messages, or the message pattern used by an endpoint. For more information, see Configuring Windows Communication Foundation Services.

binding element

A binding element represents a particular piece of the binding, such as a transport, an encoding, an implementation of an infrastructure-level protocol (such as WS-ReliableMessaging), or any other component of the communication stack.

behaviors

A behavior is a component that controls various run-time aspects of a service, an endpoint, a particular operation, or a client. Behaviors are grouped according to scope: common behaviors affect all endpoints globally, service behaviors affect only service-related aspects, endpoint behaviors affect only endpoint-related properties, and operation-level behaviors affect particular operations. For example, one service behavior is throttling, which specifies how a service reacts when an excess of messages threaten to overwhelm its handling capabilities. An endpoint behavior, on the other hand, controls only aspects relevant to endpoints, such as how and where to find a security credential.

system-provided bindings

WCF includes a number of system-provided bindings. These are collections of binding elements that are optimized for specific scenarios. For example, the WSHttpBinding is designed for interoperability with services that implement various WS-* specifications. These predefined bindings save time by presenting only those options that can be correctly applied to the specific scenario. If a predefined binding does not meet your requirements, you can create your own custom binding.

configuration versus coding

Control of an application can be done either through coding, through configuration, or through a combination of both. Configuration has the advantage of allowing someone other than the developer (for example, a network administrator) to set client and service parameters after the code is written and without having to recompile. Configuration not only enables you to set values like endpoint addresses, but also allows further control by enabling you to add endpoints, bindings, and behaviors. Coding allows the developer to retain strict control over all components of the service or client, and any settings done through the configuration can be inspected and if needed overridden by the code.

service operation

A service operation is a procedure defined in a service's code that implements the functionality for an operation. This operation is exposed to clients as methods on a WCF client. The method may return a value, and may take an optional number of arguments, or take no arguments, and return no response. For example, an operation that functions as a simple "Hello" can be used as a notification of a client's presence and to begin a series of operations.

service contract

The service contract ties together multiple related operations into a single functional unit. The contract can define service-level settings, such as the namespace of the service, a corresponding callback contract, and other such settings. In most cases, the contract is defined by creating an interface in the programming language of your choice and applying the ServiceContractAttribute attribute to the interface. The actual service code results by implementing the interface.

operation contract

An operation contract defines the parameters and return type of an operation. When creating an interface that defines the service contract, you signify an operation contract by applying the OperationContractAttribute attribute to each method definition that is part of the contract. The operations can be modeled as taking a single message and returning a single message, or as taking a set of types and returning a type. In the latter case, the system will determine the format for the messages that need to be exchanged for that operation.

message contract

A message contract describes the format of a message. For example, it declares whether message elements should go in headers versus the body, what level of security should be applied to what elements of the message, and so on.

fault contract

A fault contract can be associated with a service operation to denote errors that can be returned to the caller. An operation can have zero or more faults associated with it. These errors are SOAP faults that are modeled as exceptions in the programming model.

data contract

The data types a service uses must be described in metadata to enable others to interoperate with the service. The descriptions of the data types are known as the data contract, and the types can be used in any part of a message, for example, as parameters or return types. If the service is using only simple types, there is no need to explicitly use data contracts.

hosting

A service must be hosted in some process. A host is an application that controls the lifetime of the service. Services can be self-hosted or managed by an existing hosting process.

self-hosted service

A self-hosted service is one that runs within a process application that the developer created. The developer controls its lifetime, sets the properties of the service, opens the service (which sets it into a listening mode), and closes the service.

hosting process

A hosting process is an application that is designed to host services. These include Internet Information Services (IIS), Windows Activation Services (WAS), and Windows Services. In these hosted scenarios, the host controls the lifetime of the service. For example, using IIS you can set up a virtual directory that contains the service assembly and configuration file. When a message is received, IIS starts the service and controls its lifetime.

instancing

A service has an instancing model. There are three instancing models: "single," in which a single CLR object services all the clients; "per call," in which a new CLR object is created to handle each client call; and "per session," in which a set of CLR objects are created, one for each separate session. The choice of an instancing model depends on the application requirements and the expected usage pattern of the service.

client application

A client application is a program that exchanges messages with one or more endpoints. The client application begins by creating an instance of a WCF client and calling methods of the WCF client. It is important to note that a single application can be both a client and a service.

channel

A channel is a concrete implementation of a binding element. The binding represents the configuration, and the channel is the implementation associated with that configuration. Therefore, there is a channel associated with each binding element. Channels stack on top of each other to create the concrete implementation of the binding: the channel stack.

WCF client

A WCF client is a client-application construct that exposes the service operations as methods (in the .NET Framework programming language of your choice, such as Visual Basic or Visual C#). Any application can host a WCF client, including an application that hosts a service. Therefore, it is possible to create a service that includes WCF clients of other services.

A WCF client can be automatically generated by using the ServiceModel Metadata Utility Tool (Svcutil.exe) and pointing it at a running service that publishes metadata.

metadata

The metadata of a service describes the characteristics of the service that an external entity needs to understand to communicate with the service. Metadata can be consumed by the ServiceModel Metadata Utility Tool (Svcutil.exe) to generate a WCF client and accompanying configuration that a client application can use to interact with the service.

The metadata exposed by the service includes XML schema documents, which define the data contract of the service, and WSDL documents, which describe the methods of the service.

When enabled, metadata for the service is automatically generated by WCF by inspecting the service and its endpoints. To publish metadata from a service, you must explicitly enable the metadata behavior.

security

Security in WCF includes confidentiality (encryption of messages to prevent eavesdropping), integrity (the means for detection of tampering with the message), authentication (the means for validation of servers and clients), and authorization (the control of access to resources). These functions are provided by either leveraging existing security mechanisms, such as TLS over HTTP (also known as HTTPS), or by implementing one or more of the various WS-* security specifications.

transport security mode

Security can be provided by one of three modes: transport mode, message security mode, and transport with message credential mode. The transport security mode specifies that confidentiality, integrity, and authentication are provided by the transport layer mechanisms (such as HTTPS). When using a transport like HTTPS, this mode has the advantage of being efficient in its performance, and well understood because of its prevalence on the Internet. The disadvantage is that this kind of security is applied separately on each hop in the communication path, making the communication susceptible to a "man in the middle" attack.

message security mode

Message security mode specifies that security is provided by implementing one or more of the security specifications, such as the specification named "Web Services Security: SOAP Message Security" (available at http://go.microsoft.com/fwlink/?LinkId=94684). Each message contains the necessary mechanisms to provide security during its transit, and to enable the receivers to detect tampering and to decrypt the messages. In this sense, the security is encapsulated within every message, providing end-to-end security across multiple hops. Because security information becomes part of the message, it is also possible to include multiple kinds of credentials with the message (these are referred to as claims). This approach also has the advantage of enabling the message to travel securely over any transport, including multiple transports between its origin and destination. The disadvantage of this approach is the complexity of the cryptographic mechanisms employed, resulting in performance implications.

transport with message credential security mode

This mode uses the transport layer to provide confidentiality, authentication, and integrity of the messages, while each of the messages can contain multiple credentials (claims) required by the receivers of the message.

WS-*

Shorthand for the growing set of Web Service (WS) specifications, such as WS-Security, WS-ReliableMessaging, and so on, that are implemented in WCF.

Xml Rss Blog Feed In Asp.Net

2009-01-17T00:20:00.000-08:00

Rss feed using XmlDataSource Control & Data bound control( here I had used datalist)

Method Overloading Example

2009-01-15T07:59:00.001-08:00

public class AddingNumbers { /// /// Method Overloading /// /// Example : Console.WriteLine() & System.Math.Sign() /// overloading a method when you for some reason need a couple of methods that take different perameters, /// but conceptually do the same thing. /// /// /// /// public int Add(int a, int b) { return a + b; } public int Add(int a, int b, int c) { return a + b + c; } // Error'OOPS_Overloading.Program.AddingNumbers' already defines a member called 'Add' with the same parameter types C:\Documents and Settings\milindm\My Documents\Visual Studio 2005\Projects\OOPS_Overloading\OOPS_Overloading\Program.cs 21 27 OOPS_Overloading /* public string Add(int a, int b, int c) { return Convert.ToString(a + b + c); }*/ } static void Main(string[] args) { AddingNumbers obj = new AddingNumbers(); Console.WriteLine( "Result1: {0}",obj.Add(1,2)); Console.WriteLine("Result2: {0}", obj.Add(1, 2, 5)); Console.ReadKey(); }

Interface Example

2009-01-15T06:47:00.001-08:00

Interface Example interface IPoint { // Property signatures: int x { get; set;} int y { get; set;} // method signature void print_points(); } class Point : IPoint { // Fields: private int _x; private int _y; // Constructor: public Point(int x, int y) { _x = x; _y = y; } // Property Implementation: public int x { get { return _x; } set { _x = value; } } public int y { get { return _y; } set { _y = value; } } // Method Implementation public void print_points() { Console.WriteLine("{0} {1}", _x, _y); } } class Program { /// /// Interface /// /// -An interface contains only the signatures of methods, properties, events or indexers. /// -An Interface can not be intiated /// -An Interface can be inherited /// -All the members are public /// -multiple inheritace is possible /// -An interface is like an abstract base class: any non-abstract type inheriting the interface must implement all its members. /// -An interface cannot be instantiated directly. /// -Interfaces contain no implementation of methods. /// -Classes and structs can inherit from more than one interface. /// -An interface can itself inherit from multiple interfaces. static void PrintPoint(IPoint p) { Console.WriteLine("x={0}, y={1}", p.x, p.y); } /// /// static void Main(string[] args) { Point p = new Point(2, 3); Console.Write("My Point: "); PrintPoint(p); p.print_points(); Console.ReadKey(); } }

Abstract Example

2009-01-15T05:45:00.000-08:00

abstract class BaseClass // Abstract class { protected int _x = 100; protected int _y = 150; public abstract void AbstractMethod(); // Abstract method public abstract int X { get; } public abstract int Y { get; } } class Program : BaseClass { ///

/// Abstract Class /// /// Use the abstract modifier in a method or property declaration to indicate that the method /// or property does not contain implementation. /// Use the abstract modifier in a class declaration to indicate that a class is intended only /// to be a base class of other classes. /// The abstract modifier can be used with classes, methods, properties, indexers, and events. /// /// -An abstract class cannot be instantiated. /// -An abstract class class cannot be inherited. /// -An abstract class may contain abstract methods and accessors. /// -A non-abstract class derived from an abstract class must include actual implementations /// of all inherited abstract methods and accessors. /// /// Abstract methods /// /// -An abstract method is implicitly a virtual method. /// -Abstract method declarations are only permitted in abstract classes. /// -It is an error to use the static or virtual modifiers in an abstract method declaration. /// /// Abstract properties /// /// -Abstract properties behave like abstract methods, except for the differences in declaration and invocation syntax. /// -It is an error to use the abstract modifier on a static property. /// -An abstract inherited property can be overridden in a derived class by including a property declaration that uses /// the override modifier. /// /// /// An abstract class must provide implementation for all interface members. /// /*interface I { void M(); } abstract class C: I { public abstract void M(); } */ public override void AbstractMethod() { _x++; _y++; } public override int X // overriding property { get { return _x + 10; } } public override int Y // overriding property { get { return _y + 10; } } static void Main(string[] args) { Program o = new Program(); o.AbstractMethod(); Console.WriteLine("x = {0}, y = {1}", o.X, o.Y); Console.ReadKey(); /*Output x = 111, y = 161*/ } }

Static Constructor Example

2009-01-15T05:18:00.001-08:00

/// /// A static constructor is used to initialize any static data, or to perform a particular action that /// needs performed once only. It is called automatically before the first instance is created or any /// static members are referenced. /// /// -A static constructor does not take access modifiers or have parameters. /// -A static constructor is called automatically to initialize the class before the first instance is created /// or any static members are referenced. /// -A static constructor cannot be called directly. /// -The user has no control on when the static constructor is executed in the program. /// -A typical use of static constructors is when the class is using a log file and the constructor is used /// to write entries to this file. /// -Static constructors are also useful when creating wrapper classes for unmanaged code, when the constructor /// can call the LoadLibrary method. /// /// /// class A { static A() { System.Console.WriteLine("The static constructor invoked."); } public static void Test() { System.Console.WriteLine("The Drive method invoked."); } } static void Main(string[] args) { A.Test(); // OutOut // The static constructor invoked. // The Drive method invoked. }

Sealed Class Example

2009-01-15T05:06:00.001-08:00

/// /// Sealed Class /// /// You can Initiate the class /// You can not Inherit the class : class B : A { } /// Structs are implicitly sealed; therefore, they cannot be inherited. /// System.Threading.Thread /// /// sealed class A { public A() { } public void Test1() { } public static void Test2() { } } /*//Error : 'OOPS_Sealed.Program.B': cannot derive from sealed type 'OOPS_Sealed.Program.A' class B : A { }*/ static void Main(string[] args) { A obj = new A(); A.Test2(); }

Go through Static class example

2009-01-15T04:52:00.000-08:00

///

/// Static Class /// /// You can not Initiate : A obj = new A(); /// You can not Inherited : class B : A { } /// All the members in Static class are static /// They cannot contain Instance Constructors : public A { } /// /// static class A { /* Error 'test': cannot declare instance members in a static class public void test() { } */ public static void test() { } } /*Error cannot derive from static class 'OOPS_Concept.Program.A' class B : A { } */ static void Main(string[] args) { /* Error 1 Cannot declare variable of static type 'OOPS_Concept.Program.A' Error 2 Cannot create an instance of the static class 'OOPS_Concept.Program.A' A obj = new A();*/ A.test(); }

In Windows application Tag Property of radio button (controls) is useful as like value field of controls in web Application

2008-09-24T03:39:00.000-07:00

I don't have so much experience in windows application.. at that time i have gone through internet for Value Filed property of Controls in windows application. but i haven't find any link then i have gone through Property windows of Radio Button (any control).then I used that TAG property like a value field as we are using in web application. I used it in one of my desktop application.see this one of the step of XML Operation(XMLNodeIterator) for eg. rbButton.Tag = (object)xNodeIterator.Current.GetAttribute("ansId", "");

How to get motherboard serial number, Processor ID, VolumeSerialNumber using C#?

2008-09-24T03:23:00.000-07:00

Add using System.Management; namespace in your application then //Get motherboard's serial number ManagementObjectSearcher mbs = new ManagementObjectSearcher("Select * From Win32_BaseBoard"); foreach (ManagementObject mo in mbs.Get()) { textBox1.Text = mo["SerialNumber"].ToString(); } //Get Processor's Identity mbs = new ManagementObjectSearcher("Select * From Win32_processor"); foreach (ManagementObject mo in mbs.Get()) { textBox2.Text = mo["ProcessorID"].ToString(); } //Get Network Adapter Configuration mbs = new ManagementObjectSearcher("Select * From Win32_NetworkAdapterConfiguration"); foreach (ManagementObject mo in mbs.Get()) { textBox3.Text = mo["MACAddress"].ToString(); break; } //Get Network Adapter Configuration mbs = new ManagementObjectSearcher("Select * From win32_logicaldisk"); foreach (ManagementObject mo in mbs.Get()) { textBox4.Text = mo["VolumeSerialNumber"].ToString(); }

Building and Consuming XML web services

2008-06-03T02:43:00.000-07:00

Creating Web Service using System; using System.Web; using System.Web.Services; using System.Web.Services.Protocols; [WebService(Namespace = "http://tempuri.org/")] [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)] public class HelloHeader : SoapHeader { public string Username; public string Password; } public class HelloSoapHeader : System.Web.Services.WebService { public HelloHeader myHeader; [WebMethod] [SoapHeader("myHeader")] public string HelloWorld() { System.Threading.Thread.Sleep(1000); if (myHeader == null) return "Hello World"; else return "Hello " + myHeader.Username + " Your Password is :" + myHeader.Password; } } Consumming web service Synchronously using System; using System.Data; using System.Configuration; using System.Collections; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Web.UI.HtmlControls; public partial class ConsumeSynchronously : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { localhost.HelloHeader wsHeader = new localhost.HelloHeader(); localhost.HelloSoapHeader ws = new localhost.HelloSoapHeader(); wsHeader.Username = "Milind Mahajan"; wsHeader.Password = "just testing"; ws.HelloHeaderValue = wsHeader; ws.SoapVersion = System.Web.Services.Protocols.SoapProtocolVersion.Soap12; Label1.Text = ws.HelloWorld(); } } Consumming web service Asynchronously using System; using System.Data; using System.Configuration; using System.Collections; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Web.UI.HtmlControls; public partial class ConsumeASynchronously : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { localhost.HelloHeader wsHeader = new localhost.HelloHeader(); localhost.HelloSoapHeader ws = new localhost.HelloSoapHeader(); wsHeader.Username = "Milind Mahajan"; wsHeader.Password = "just testing"; ws.HelloHeaderValue = wsHeader; ws.SoapVersion = System.Web.Services.Protocols.SoapProtocolVersion.Soap12; //AsyncCallback cb = new AsyncCallback(ServiceCallback); IAsyncResult myIar; myIar = ws.BeginHelloWorld(null,null); int x = 0; while (myIar.IsCompleted == false) { x += 1; } Label1.Text = "Result from web service: " + ws.EndHelloWorld(myIar) + " Local Count While Waiting : " + x.ToString(); } //private void ServiceCallback(IAsyncResult ar) //{ // // Cast the AsyncState object to the proxy object // localhost.HelloSoapHeader ws = (localhost.HelloSoapHeader)ar.AsyncState; // // Call the End method and assign the response to a DataSet // //Use the lock statement to prevent other threads from accessing // //the listview until you have finished updating it // string str = ws.EndHelloWorld(ar); // lock (this.Label1) // { // Label1.Text = str; // } //} }

Web page execution

2008-03-07T01:49:00.000-08:00

This article is copied from

http://www.c-sharpcorner.com/UploadFile/hima_.net/WebPageExecutioninIIS05162006054117AM/WebPageExecutioninIIS.aspx

How the Simple Web page execution Happens?

As All of us know A Request comes from Client (Browser) and sends to Server (We call it as Web server) in turn Server Process the Request and sends response Back to the Client in according to the client Request

But internally in the Web server there is quite interesting process that happens. To get aware of that process we should first of all know about the architecture of the IIS

It mainly consists of 3 Parts/Files

1. Inetinfo.exec

2. ISAPI Filter (Container for Internet Server Application Interface dlls) ,

3. Worker Process (aspnet_wp.exe)

When ever a Request comes from the Client:

Inetinfo.exe is the ASP.Net Request Handler that handles the requests from the client .If it’s for static resources like HTML files or image files inetinfo.exe process the request and sent to client If the request is with extension aspx/asp inetinfo.exe processes the request to API filter. ISAPI filter will have several runtime modules called as ISAPI extensions. To process the request ISAPI filter takes the help of these runtime modules .The runtime module loaded for asp page is asp.dll. And for asp.net page it’s ASPNET_ISAPI.dll. From here the request is processed o the Worker Process. Worker Process will have several Application Domains

Application Domain

The purpose of the Application Domain is in order to isolate one application from another. When ever we create a new application, application Domains are created automatically by the CLRHost. Worker process will create a block of memory related to particular application. Application domains provide a more secure and versatile unit of processing that the common language runtime can use to provide isolation between applications. Application domains are normally created by runtime hosts. Runtime host is responsible for bootstrapping the common language runtime before an application is run.

Worker process sends the request to HTTPPIPE line.(HTTP Pipeline is nonetheless collection of .net framework classes). HTTP Pipeline compiles the request into a library and -makes a call to HTTP runtime and Runtime creates an instance of page class

public class File : System.Web.UI.Page

{

}

ASP.Net web page is a class derived from Page class ,this page class resides in system.web.dll

After creating instance pf Page class HTTP Runtime immediately invokes Process Request Method of Page class

Page Req = new Page();

Req.ProcessRequest();

Process Request Method Does Following things

1.Intialize the Memory

2.Load the View State

3.Page Execution and Post back Events

4.Rendering HTML Content

5.Releasing the memory

Process Request Method executes set of events for page class .These are calles as Page life cycle events.

Page Life Cycle Events

Page_Init
The server controls are loaded and initialized from the Web form’s view state. This is the first step in a Web form’s life cycle.

Page_Load
The server controls are loaded in the Page object. View state information is available at this point, so this is where you put code to change control settings or display text on the page.

Page_PreRender
The application is about to render the Page object.

Page_Unload
The page is unloaded from memory.

Page_Disposed
The Page object is released from memory. This is the last event in the life of a Page object.

Page_Error
An unhandled exception occurs.

Page_AbortTransaction
A transaction is aborted.

Page_CommitTransaction
A transaction is accepted.

Page_DataBinding
A server control on the page binds to a data source.

Process Request Method finally renders HTML Page

Dependencies:

When the request comes to ASP.net worker Process, it will be forwarded to HTTP Application factory. This Application Factory will maintain address of the Application Domains which are currently executing under worker process. If the required virtual directory application domain is unavailable it will create a new Application Domain. If the application domain is already existent, the request will be forwarded to Corresponding AppDomain.

Application Domain maintains Page handler factory class. This will contain all libraries addresses corresponding to webpage. If the requested webpage library is available the instance of the page class is created, if the library is unavailable the request will be forwarded to http pipeline.

asp.net questions

2008-01-30T03:21:00.001-08:00

What do I need to create and run an ASP.NET application?

Windows 2000, Windows Server 2003 or Windows XP.
ASP.NET, which can be either the redistributable (included in the .NET SDK) or Visual Studio .NET.

Where can I download the .NET SDK?
.NET SDK can be obtained here.

(You have to install the Microsoft .NET Framework Version 1.1 Redistributable Package before installing the .NET SDK.)
Are there any free IDEs for the .NET SDK?
- Microsoft provides Visual Studio 2005 Express Edition Beta for free. Of particular interest to the ASP.NET developers would be the Visual Web Developer 2005 Express Edition Beta 2 available as a free download.
- The ASP.NET Web Matrix Project (supported by Microsoft) is a free IDE for developing ASP.NET applications and is available here.
- There is also a free open-source UNIX version of the Microsoft .NET development platform called Mono available for download here.
- Another increasingly popular Open Source Development Environment for .NET is the #develop (short for SharpDevelop) available for download here.
When was ASP.NET released?
ASP.NET is a part of the .NET framework which was released as a software platform in 2002.
Is a new version coming up?
ASP.NET 2.0, Visual Studio 2005 (Whidbey), Visual Web Developer 2005 Express Edition are the next releases of Microsoft's Web platform and tools. They have already been released as Beta versions. They are scheduled to be released in the week of November 7, 2005.
Explain Namespace.
Namespaces are logical groupings of names used within a program. There may be multiple namespaces in a single application code, grouped based on the identifiers’ use. The name of any given identifier must appear only once in its namespace.
List the types of Authentication supported by ASP.NET.
- Windows (default)
- Forms
- Passport
- None (Security disabled)
What is CLR?
Common Language Runtime (CLR) is a run-time environment that manages the execution of .NET code and provides services like memory management, debugging, security, etc. The CLR is also known as Virtual Execution System (VES).
What is CLI?
The CLI is a set of specifications for a runtime environment, including a common type system, base class library, and a machine-independent intermediate code known as the Common Intermediate Language (CIL). (Source: Wikipedia.)
List the various stages of Page-Load lifecycle.
- Init()
- Load()
- PreRender()
- Unload()
Explain Assembly and Manifest.
An assembly is a collection of one or more files and one of them (DLL or EXE) contains a special metadata called Assembly Manifest. The manifest is stored as binary data and contains details like versioning requirements for the assembly, the author, security permissions, and list of files forming the assembly. An assembly is created whenever a DLL is built. The manifest can be viewed programmatically by making use of classes from the System.Reflection namespace. The tool Intermediate Language Disassembler (ILDASM) can be used for this purpose. It can be launched from the command prompt or via Start> Run.
What is Shadow Copy?
In order to replace a COM component on a live web server, it was necessary to stop the entire website, copy the new files and then restart the website. This is not feasible for the web servers that need to be always running. .NET components are different. They can be overwritten at any time using a mechanism called Shadow Copy. It prevents the Portable Executable (PE) files like DLLs and EXEs from being locked. Whenever new versions of the PEs are released, they are automatically detected by the CLR and the changed components will be automatically loaded. They will be used to process all new requests not currently executing, while the older version still runs the currently executing requests. By bleeding out the older version, the update is completed.
What is DLL Hell?
DLL hell is the problem that occurs when an installation of a newer application might break or hinder other applications as newer DLLs are copied into the system and the older applications do not support or are not compatible with them. .NET overcomes this problem by supporting multiple versions of an assembly at any given time. This is also called side-by-side component versioning.
Explain Web Services.
Web services are programmable business logic components that provide access to functionality through the Internet. Standard protocols like HTTP can be used to access them. Web services are based on the Simple Object Access Protocol (SOAP), which is an application of XML. Web services are given the .asmx extension.
Explain Windows Forms.
Windows Forms is employed for developing Windows GUI applications. It is a class library that gives developers access to Windows Common Controls with rich functionality. It is a common GUI library for all the languages supported by the .NET Framework.
What is Postback?
When an action occurs (like button click), the page containing all the controls within the tag performs an HTTP POST, while having itself as the target URL. This is called Postback.
Explain the differences between server-side and client-side code?
Server side scripting means that all the script will be executed by the server and interpreted as needed. Client side scripting means that the script will be executed immediately in the browser such as form field validation, clock, email validation, etc. Client side scripting is usually done in VBScript or JavaScript. Since the code is included in the HTML page, anyone can see the code by viewing the page source. It also poses as a possible security hazard for the client computer.
Enumerate the types of Directives.
- @ Page directive
- @ Import directive
- @ Implements directive
- @ Register directive
- @ Assembly directive
- @ OutputCache directive
- @ Reference directive
What is Code-Behind?
Code-Behind is a concept where the contents of a page are in one file and the server-side code is in another. This allows different people to work on the same page at the same time and also allows either part of the page to be easily redesigned, with no changes required in the other. An Inherits attribute is added to the @ Page directive to specify the location of the Code-Behind file to the ASP.NET page.
Describe the difference between inline and code behind.
Inline code is written along side the HTML in a page. There is no separate distinction between design code and logic code. Code-behind is code written in a separate file and referenced by the .aspx page.
List the ASP.NET validation controls?
- RequiredFieldValidator
- RangeValidator
- CompareValidator
- RegularExpressionValidator
- CustomValidator
- ValidationSummary
What is Data Binding?
Data binding is a way used to connect values from a collection of data (e.g. DataSet) to the controls on a web form. The values from the dataset are automatically displayed in the controls without having to write separate code to display them.
Describe Paging in ASP.NET.
The DataGrid control in ASP.NET enables easy paging of the data. The AllowPaging property of the DataGrid can be set to True to perform paging. ASP.NET automatically performs paging and provides the hyperlinks to the other pages in different styles, based on the property that has been set for PagerStyle.Mode.
Should user input data validation occur server-side or client-side? Why?
All user input data validation should occur on the server and minimally on the client-side, though it is a good way to reduce server load and network traffic because we can ensure that only data of the appropriate type is submitted from the form. It is totally insecure. The user can view the code used for validation and create a workaround for it. Secondly, the URL of the page that handles the data is freely visible in the original form page. This will allow unscrupulous users to send data from their own forms to your application. Client-side validation can sometimes be performed where deemed appropriate and feasible to provide a richer, more responsive experience for the user.
What is the difference between Server.Transfer and Response.Redirect?
- Response.Redirect: This tells the browser that the requested page can be found at a new location. The browser then initiates another request to the new page loading its contents in the browser. This results in two requests by the browser.
- Server.Transfer: It transfers execution from the first page to the second page on the server. As far as the browser client is concerned, it made one request and the initial page is the one responding with content. The benefit of this approach is one less round trip to the server from the client browser. Also, any posted form variables and query string parameters are available to the second page as well.

Web Services

2008-01-28T01:34:00.001-08:00

Asp Net Web Services: Here are some web services interview questions which is very helpful in interviews. This great listing of interview questions provides a lot of information on Web Services Questions and Web Services Faqs. Not at all, instead of web services faqs and interview questions you can also learn how to use web services in asp net. If you need more web services faqs used in asp net you can also contact us for more info। Question: Can you define basic element of WebServices and explain any one from them? Answer: These are as follows SOAP, WSDL and UDDI. And I am explaining about the SOAP(Simple Object Access Protocol) it is a communication protocol it is for communication between application it is platform and language independent.It is based on XML and also help to get from Firwall. Question: Explain functioning of Web Services Protocols ? Answer: Http-Get:- This is standard protocol that helps client to communicate with server with HTTP.When client send a request to server via HTTP request and reuired parameter are attached with the querystring.Example:- http://www.dotnetquestion.info/dotnet/interview.aspx?id=pervej&cast=munjal and we get the value from querystring. Request.querystring("id") Request.querystring("cast"). Http-Post:-This is same as Http-Get but the diffrence is that in place of sending parameters onto the URL information is send with HTTP request message with some extra information which contains Parameters and their values.This Protocols is limited to sending name/value pairs. SOAP:-The only diffrence is that its relies on the XML as compares to Http-Get,Http-Post.SOAP can send not only the name/value pairs but also some complex object also as for example datatypes,class,objects.SOAP can also uses request/reponse model as Http-Get,Http-post but it is not limited to Request/Response it can also send types of message.Because its uses XML that is pure text so firewalls not created so much problem because its easily converted in to HTML. . Question: Why do some web service classes derive from System.Web.WebServices while others do not ? Answer: Those asp net Web Service classes which employ objects like Application, Session, Context, Server, and User have to derive from System।Web.WebServices. If it does not use these objects, it is not necessary to be derived from it. Question: What is WSDL ? Answer: WSDL is an XML format for describing network services as a set of endpoints operating on messages containing either document-oriented or procedure-oriented information. The operations and messages are described abstractly, and then bound to a concrete network protocol and message format to define an endpoint. Related concrete endpoints are combined into abstract endpoints (services). (Source: www.w3.org). Question: What is the standard you use to wrap up a call to a Web service ? Answer: HTTP with SOAP. Question: What is Asp Net Web Services ? Answer: Web services are programmable business logic components that provide access to functionality through the Internet. Standard protocols like HTTP can be used to access them. Web services are based on the Simple Object Access Protocol (SOAP), which is an application of XML. Web services are given the .asmx extension.. Question: Define Protocols that helps Web Services in Asp Net? Answer: From my point of view Web Services used three protocols for interacting with the clients.Http-Post,Http-Get,SOAP. Question: What are VSDISCO files ? Answer: VSDISCO files are DISCO files that enable dynamic discovery of Web Services. ASP.NET links the VSDISCO to a HTTP handler that scans the host directory and subdirectories for ASMX and DISCO files and returns a dynamically generated DISCO document. A client who requests a VSDISCO file gets back what appears to be a static DISCO document. Question: What is UDDI ? Answer: UDDI stands for Universal Description, Discovery, and Integration. It is like an "Yellow Pages" for Web Services. It is maintained by Microsoft, IBM, and Ariba, and is designed to provide detailed information regarding registered Web Services for all vendors. The UDDI can be queried for specific Web Services. Question: Is it possible to generate the source code for an ASP.NET Web service from a WSDL ? Answer: The Wsdl.exe tool (.NET Framework SDK) can be used to generate source code for an ASP.NET web service with its WSDL link. Example: wsdl /server http://api।google.com/GoogleSearch.wsdl. Question: Can you give an example of when it would be appropriate to use a web service as opposed to a non-serviced .NET component ? Answer: When to Use Asp Net Web Services: (i)Communicating through a Firewall When building a distributed application with 100s/1000s of users spread over multiple locations, there is always the problem of communicating between client and server because of firewalls and proxy servers. Exposing your middle tier components as Web Services and invoking the directly from a Windows UI is a very valid option. (ii)Application Integration When integrating applications written in various languages and running on disparate systems. Or even applications running on the same platform that have been written by separate vendors. (iii)Business-to-Business Integration This is an enabler for B2B intergtation which allows one to expose vital business processes to authorized supplier and customers. An example would be exposing electronic ordering and invoicing, allowing customers to send you purchase orders and suppliers to send you invoices electronically. (iv)Software Reuse This takes place at multiple levels. Code Reuse at the Source code level or binary componet-based resuse. The limiting factor here is that you can reuse the code but not the data behind it. Webservice overcome this limitation. A scenario could be when you are building an app that aggregates the functionality of serveral other Applicatons. Each of these functions could be performed by individual apps, but there is value in perhaps combining the the multiple apps to present a unifiend view in a Portal or Intranet. Question: What are Service Oriented Architectures (SOA) ? Answer: SOA describes an information technology architecture that enables distributed computing environments with many different types of computing platforms and applications. Web services in asp net are one of the technologies that help make SOAs possible. As a concept, SOA has been around since the 1980s, but many early IT technologies failed to achieve the goal of linking different types of applications and systems. By making early investments with .NET, Microsoft has helped provide the building blocks that today are putting many enterprise customers on the path to successfully implementing SOAs. With SOAs, companies can benefit from the unimpeded flow of information that is the hallmark of connected systems. Question: What is .NET Passport ? Answer: .NET Passport is a Web-based service that is designed to make signing in to Web sites fast and easy. Passport enables participating sites to authenticate a user with a single set of sign-in credentials, alleviating the need for users to remember numerous passwords and user names.

2008-01-28T01:17:00.004-08:00

Remoting is the process through which we can access any remote object from one application domain to another application domain.

For creating remote object the class object must be inherited by MarshalByRefObject class.

Application domain is the runtime environment of application, For MicrosoftWord, domain is MS office, For .NET programme, .NET runtime environment.

Terms Used in Remoting

Proxy: To avoid conjunction in networking. Main work is task Distributing.There are two type of proxy.

Transparent proxy (There is no physical existence , Created by IIS server)
Real Proxy (Physical Existence)

Channel: Channel provides the medium for transfer data from one location to another location. There are two types of channel.

TCP(work with Predefined root Connection oriented)
HTTP (No need predefined root)

Formatters: Change the data in an appropriate format that it can traverse through channels. There are two types of formatters

Binary

SOAP(Simple Object Access Protocol)

Sink: Sink is used for security point of view. Before sending the data, the Data will be encrypted. Some additional bit will be added with the data to secure the data. There are two types of sink

Envoy sink

Server Context Sink

Object Mode On Server: Two Types of Object Mode .

SingleCall

Singleton

application

What is .NET Remoting?
.NET Remoting is an enabler for application communication. It is a generic system for different applications to use to communicate with one another. .NET objects are exposed to remote processes, thus allowing interprocess communication.
What’s a Windows process?
It’s an application that’s running and had been allocated memory.
What are the consideration in deciding to use .NET Remoting or ASP.NET Web Services?
Remoting is a more efficient communication exchange when you can control both ends of the application involved in the communication process. Web Services provide an open-protocol-based exchange of informaion. Web Services are best when you need to communicate with an external organization or another (non-.NET) technology.
What are channels in .NET Remoting?
Channels represent the objects that transfer the other serialized objects from one application domain to another and from one computer to another, as well as one process to another on the same box। A channel must exist before an object can be ट्रांस्फेर्रेड.
What security measures exist for .NET Remoting in System.Runtime.Remoting?
None. Security should be taken care of at the application level. Cryptography and other security techniques can be applied at application or server level.
What is a formatter?
A formatter is an object that is responsible for encoding and serializing data into messages on one end, and deserializing and decoding messages into data on the other end.
Can you configure a .NET Remoting object via XML file?
Yes, via machine.config and application level .config file (or web.config in ASP.NET). Application-level XML settings take precedence over machine.config.
Choosing between HTTP and TCP for protocols and Binary and SOAP for formatters, what are the trade-offs?
Binary over TCP is the most effiecient, SOAP over HTTP is the most interoperable.
How do you define the lease of the object?
By implementing ILease interface when writing the class code.
What’s SingleCall activation mode used for?
If the server object is instantiated for responding to just one single request, the request should be made in SingleCall mode.

more asp.net questiuons

2008-01-04T02:36:00.000-08:00

ASP.Net Interview Questions 1. Describe the role of inetinfo.exe, aspnet_isapi.dll andaspnet_wp.exe in the page loading process. inetinfo.exe is theMicrosoft IIS server running, handling ASP.NET requests among other things.When an ASP.NET request is received (usually a file with .aspx extension), the ISAPI filter aspnet_isapi.dll takes care of it by passing the request tothe actual worker process aspnet_wp.exe. 2. What’s the difference between Response.Write() andResponse.Output.Write()? Response.Output.Write() allows you to write formatted output. 3. What methods are fired during the page load? Init() - when the page is instantiated Load() - when the page is loaded into server memory PreRender() - the brief moment before the page is displayed to the user as HTML Unload() - when page finishes loading. 4. When during the page processing cycle is ViewState available? After the Init() and before the Page_Load(), or OnLoad() for a control. 5. What namespace does the Web page belong in the .NET Framework class hierarchy? System.Web.UI.Page 6. Where do you store the information about the user’s locale? System.Web.UI.Page.Culture 7. What’s the difference between Codebehind="MyCode.aspx.cs" andSrc="MyCode.aspx.cs"? CodeBehind is relevant to Visual Studio.NET only. 8. What’s a bubbled event? When you have a complex control, like DataGrid, writing an event processing routine for each object (cell, button, row, etc.) is quite tedious. The controls can bubble up their eventhandlers, allowing the main DataGrid event handler to take care of its constituents. 9. Suppose you want a certain ASP.NET function executed on MouseOver for a certain button. Where do you add an event handler? Add an OnMouseOver attribute to the button. Example: btnSubmit.Attributes.Add("onmouseover","someClientCodeHere();"); 10. What data types do the RangeValidator control support? Integer, String, and Date. 11. Explain the differences between Server-side and Client-side code? Server-side code executes on the server. Client-side code executes in the client's browser. 12. What type of code (server or client) is found in a Code-Behind class? The answer is server-side code since code-behind is executed on the server. However, during the code-behind's execution on the server, it can render client-side code such as JavaScript to be processed in the clients browser. But just to be clear, code-behind executes on the server, thus making it server-side code. 13. Should user input data validation occur server-side or client-side? Why? All user input data validation should occur on the server at a minimum. Additionally, client-side validation can be performed where deemed appropriate and feasable to provide a richer, more responsive experience for the user. 14. What is the difference between Server.Transfer and Response.Redirect? Why would I choose one over the other? Server.Transfer transfers page processing from one page directly to the next page without making a round-trip back to the client's browser. This provides a faster response with a little less overhead on the server. Server.Transfer does not update the clients url history list or current url. Response.Redirect is used to redirect the user's browser to another page or site. This performas a trip back to the client where the client's browser is redirected to the new page. The user's browser history list is updated to reflect the new address. 15. Can you explain the difference between an ADO.NET Dataset and an ADO Recordset? Valid answers are: • A DataSet can represent an entire relational database in memory, complete with tables, relations, and views. • A DataSet is designed to work without any continuing connection to the original data source. • Data in a DataSet is bulk-loaded, rather than being loaded on demand. • There's no concept of cursor types in a DataSet. • DataSets have no current record pointer You can use For Each loops to move through the data. • You can store many edits in a DataSet, and write them to the original data source in a single operation. • Though the DataSet is universal, other objects in ADO.NET come in different versions for different data sources. 16. What is the Global.asax used for? The Global.asax (including the Global.asax.cs file) is used to implement application and session level events. 17. What are the Application_Start and Session_Start subroutines used for? This is where you can set the specific variables for the Application and Session objects. 18. Can you explain what inheritance is and an example of when you might use it? When you want to inherit (use the functionality of) another class. Example: With a base class named Employee, a Manager class could be derived from the Employee base class. 19. Whats an assembly? Assemblies are the building blocks of the .NET framework. Overview of assemblies from MSDN 20. Describe the difference between inline and code behind. Inline code written along side the html in a page. Code-behind is code written in a separate file and referenced by the .aspx page. 21. Explain what a diffgram is, and a good use for one? The DiffGram is one of the two XML formats that you can use to render DataSet object contents to XML. A good use is reading database data to an XML file to be sent to a Web Service. 22. Whats MSIL, and why should my developers need an appreciation of it if at all? MSIL is the Microsoft Intermediate Language. All .NET compatible languages will get converted to MSIL. MSIL also allows the .NET Framework to JIT compile the assembly on the installed computer. 23. Which method do you invoke on the DataAdapter control to load your generated dataset with data? The Fill() method. 24. Can you edit data in the Repeater control? No, it just reads the information from its data source. 25. Which template must you provide, in order to display data in a Repeater control? ItemTemplate. 26. How can you provide an alternating color scheme in a Repeater control? Use the AlternatingItemTemplate. 27. What property must you set, and what method must you call in your code, in order to bind the data from a data source to the Repeater control? You must set the DataSource property and call the DataBind method. 28. What base class do all Web Forms inherit from? The Page class. 29. Name two properties common in every validation control? ControlToValidate property and Text property. 30. Which property on a Combo Box do you set with a column name, prior to setting the DataSource, to display data in the combo box? DataTextField property. 31. Which control would you use if you needed to make sure the values in two different controls matched? CompareValidator control. 32. How many classes can a single .NET DLL contain? It can contain many classes. Web Service Questions 1. What is the transport protocol you use to call a Web service? SOAP (Simple Object Access Protocol) is the preferred protocol. 2. True or False: A Web service can only be written in .NET? False 3. What does WSDL stand for? Web Services Description Language. 4. Where on the Internet would you look for Web services? http://www.uddi.org 5. True or False: To test a Web service you must create a Windows application or Web application to consume this service? False, the web service comes with a test page and it provides HTTP-GET method to test. State Management Questions 1. What is ViewState? ViewState allows the state of objects (serializable) to be stored in a hidden field on the page. ViewState is transported to the client and back to the server, and is not stored on the server or any other external source. ViewState is used the retain the state of server-side objects between postabacks. 2. What is the lifespan for items stored in ViewState? Item stored in ViewState exist for the life of the current page. This includes postbacks (to the same page). 3. What does the "EnableViewState" property do? Why would I want it on or off? It allows the page to save the users input on a form across postbacks. It saves the server-side values for a given control into ViewState, which is stored as a hidden value on the page before sending the page to the clients browser. When the page is posted back to the server the server control is recreated with the state stored in viewstate. 4. What are the different types of Session state management options available with ASP.NET? ASP.NET provides In-Process and Out-of-Process state management. In-Process stores the session in memory on the web server. This requires the a "sticky-server" (or no load-balancing) so that the user is always reconnected to the same web server. Out-of-Process Session state management stores data in an external data source. The external data source may be either a SQL Server or a State Server service. Out-of-Process state management requires that all objects stored in session are serializable.

oops questions

2008-01-04T02:34:00.000-08:00

OOPs questions

Inheritance

The process of sub-classing a class to extend its functionality is called Inheritance.It provides idea of reusability.

Order of Constructor execution in Inheritance

constructors are called in the order from the top to the bottom (parent to child class) in inheritance hierarchy.

Order of Destructor execution in Inheritance

The destructors are called in the reverse order, i.e., from the bottom to the top (child to parent class) in the inheritance hierarchy.

What are Sealed Classes in C#? The sealed modifier is used to prevent derivation from a class. A compile-time error occurs if a sealed class is specified as the base class of another class. (A sealed class cannot also be an abstract class)

Can you prevent your class from being inherited by another class? Yes. The keyword “sealed” will prevent the class from being inherited. Can you allow a class to be inherited, but prevent the method from being over-ridden? Yes. Just leave the class public and make the method sealed.

Fast Facts of Inheritance

Multiple inheritance of classes is not allowed in C#.

In C# you can implements more than one interface, thus multiple inheritance is achieved through interface. The Object class defined in the System namespace is implicitly the ultimate base class of all the classes in C# (and the .NET framework)

Structures (struct) in C# does not support inheritance, it can only implements interfaces.

Polymorphism

Polymorphism means same operation may behave differently on different classes.

Eg: Method Overloading is an example of Compile Time Polymorphism.

Method Overriding is an example of Run Time Polymorphism

Does C#.net supports multiple inheritance?

No. A class can inherit from only one base class, however a class can implements many interface, which servers some of the same purpose without increasing complexity.

How many types of Access Modifiers.

1) Public – Allows the members to be globally accessible.

2) Private – Limits the member’s access to only the containing type.

3) Protected – Limits the member’s access to the containing type and all classes derived from the containing type.

4) Internal – Limits the member’s access to within the current project.

Method Overloading

Method with same name but with different arguments is called method overloading.

Method Overloading forms compile-time polymorphism.

Eg:

class A1{

void hello()

{ Console.WriteLine(“Hello”); }

void hello(string s)

{ Console.WriteLine(“Hello {0}”,s); }

}

Method Overriding

Method overriding occurs when child class declares a method that has the same type arguments as a method declared by one of its superclass.

Method overriding forms Run-time polymorphism.

Note: By default functions are not virtual in C# and so you need to write “virtual” explicitly. While by default in Java each function are virtual.

Eg1:

Class parent

{

virtual void hello()

{ Console.WriteLine(“Hello from Parent”); }

}

Class child : parent

{

override void hello()

{ Console.WriteLine(“Hello from Child”); }

}

static void main()

{

parent objParent = new child();

objParent.hello();

}

//Output

Hello from Child.

Virtual Method

By declaring base class function as virtual, we allow the function to be overridden in any of derived class.

Eg:

Class parent

{

virtual void hello()

{ Console.WriteLine(“Hello from Parent”); }

}

Class child : parent

{

override void hello()

{ Console.WriteLine(“Hello from Child”); }

}

static void main()

{

parent objParent = new child();

objParent.hello();

}

//Output

Hello from Child.

What is Interface

· An Interface is a group of constants and method declaration.

· .Net supports multiple inheritance through Interface.

· Interface states “what” to do, rather than “how” to do.

· An interface defines only the members that will be made available by an implementing object. The definition of the interface states nothing about the implementation of the members, only the parameters they take and the types of values they will return. Implementation of an interface is left entirely to the implementing class. It is possible, therefore, for different objects to provide dramatically different implementations of the same members.

· Example1, the Car object might implement the IDrivable interface (by convention, interfaces usually begin with I), which specifies the GoForward, GoBackward, and Halt methods. Other classes, such as Truck, Aircraft, Train or Boat might implement this interface and thus are able to interact with the Driver object. The Driver object is unaware of which interface implementation it is interacting with; it is only aware of the interface itself.

· Example2, an interface named IShape, which defines a single method CalculateArea. A Circle class implementing this interface will calculate its area differently than a Square class implementing the same interface. However, an object that needs to interact with an IShape can call the CalculateArea method in either a Circle or a Square and obtain a valid result.

· Practical Example

public interface IDrivable { void GoForward(int Speed); } public class Truck : IDrivable { public void GoForward(int Speed) { // Implementation omitted } } public class Aircraft : IDrivable { public void GoForward(int Speed) { // Implementation omitted } } public class Train : IDrivable { public void GoForward(int Speed) { // Implementation omitted } }

Extra

· Each variable declared in interface must be assigned a constant value.

· Every interface variable is implicitly public, static and final.

· Every interface method is implicitly public and abstract.

· Interfaces are allowed to extends other interfaces, but sub interface cannot define the methods declared in the super interface, as sub interface is still interface and not class.

· If a class that implements an interface does not implements all the methods of the interface, then the class becomes an abstract class and cannot be instantiated.

· Both classes and structures can implement interfaces, including multiple interfaces.

In which Scenario you will go for Interface or Abstract Class?



Interfaces, like classes, define a set of properties, methods, and events. But unlike classes, interfaces

do not provide implementation. They are implemented by classes, and defined as separate entities from

classes. Even though class inheritance allows your classes to inherit implementation from a base class, it

also forces you to make most of your design decisions when the class is first published.



Abstract classes are useful when creating components because they allow you specify an invariant level

of functionality in some methods, but leave the implementation of other methods until a specific

implementation of that class is needed. They also version well, because if additional functionality is

needed in derived classes, it can be added to the base class without breaking code.

Interview Questions c#

2008-01-04T02:15:00.001-08:00

Interview Questions

What’s the implicit name of the parameter that gets passed into the class’ set method? Value, and its datatype depends on whatever variable we’re changing.
How do you inherit from a class in C#? Place a colon and then the name of the base class. Notice that it’s double colon in C++.
Does C# support multiple inheritance? No, use interfaces instead.
When you inherit a protected class-level variable, who is it available to? Classes in the same namespace.
Are private class-level variables inherited? Yes, but they are not accessible, so looking at it you can honestly say that they are not inherited. But they are.
Describe the accessibility modifier protected internal. It’s available to derived classes and classes within the same Assembly (and naturally from the base class it’s declared in).
C# provides a default constructor for me. I write a constructor that takes a string as a parameter, but want to keep the no parameter one. How many constructors should I write? Two. Once you write at least one constructor, C# cancels the freebie constructor, and now you have to write one yourself, even if there’s no implementation in it.
What’s the top .NET class that everything is derived from? System.Object.
How’s method overriding different from overloading? When overriding, you change the method behavior for a derived class. Overloading simply involves having a method with the same name within the class.
What does the keyword virtual mean in the method definition? The method can be over-ridden.
Can you declare the override method static while the original method is non-static? No, you can’t, the signature of the virtual method must remain the same, only the keyword virtual is changed to keyword override.
Can you override private virtual methods? No, moreover, you cannot access private methods in inherited classes, have to be protected in the base class to allow any sort of access.
Can you prevent your class from being inherited and becoming a base class for some other classes? Yes, that’s what keyword sealed in the class definition is for. The developer trying to derive from your class will get a message: cannot inherit from Sealed class WhateverBaseClassName. It’s the same concept as final class in Java.
Can you allow class to be inherited, but prevent the method from being over-ridden? Yes, just leave the class public and make the method sealed.
What’s an abstract class? A class that cannot be instantiated. A concept in C++ known as pure virtual method. A class that must be inherited and have the methods over-ridden. Essentially, it’s a blueprint for a class without any implementation.
When do you absolutely have to declare a class as abstract (as opposed to free-willed educated choice or decision based on UML diagram)? When at least one of the methods in the class is abstract. When the class itself is inherited from an abstract class, but not all base abstract methods have been over-ridden.
What’s an interface class? It’s an abstract class with public abstract methods all of which must be implemented in the inherited classes.
Why can’t you specify the accessibility modifier for methods inside the interface? They all must be public. Therefore, to prevent you from getting the false impression that you have any freedom of choice, you are not allowed to specify any accessibility, it’s public by default.
Can you inherit multiple interfaces? Yes, why not.
And if they have conflicting method names? It’s up to you to implement the method inside your own class, so implementation is left entirely up to you. This might cause a problem on a higher-level scale if similarly named methods from different interfaces expect different data, but as far as compiler cares you’re okay.
What’s the difference between an interface and abstract class? In the interface all methods must be abstract; in the abstract class some methods can be concrete. In the interface no accessibility modifiers are allowed, which is ok in abstract classes.
How can you overload a method? Different parameter data types, different number of parameters, different order of parameters.
If a base class has a bunch of overloaded constructors, and an inherited class has another bunch of overloaded constructors, can you enforce a call from an inherited constructor to an arbitrary base constructor? Yes, just place a colon, and then keyword base (parameter list to invoke the appropriate constructor) in the overloaded constructor definition inside the inherited class.
What’s the difference between System.String and System.StringBuilder classes? System.String is immutable; System.StringBuilder was designed with the purpose of having a mutable string where a variety of operations can be performed.
What’s the advantage of using System.Text.StringBuilder over System.String? StringBuilder is more efficient in the cases, where a lot of manipulation is done to the text. Strings are immutable, so each time it’s being operated on, a new instance is created.
Can you store multiple data types in System.Array? No.
What’s the difference between the System.Array.CopyTo() and System.Array.Clone()? The first one performs a deep copy of the array, the second one is shallow.
How can you sort the elements of the array in descending order? By calling Sort() and then Reverse() methods.
What’s the .NET datatype that allows the retrieval of data by a unique key? HashTable.
What’s class SortedList underneath? A sorted HashTable.
Will finally block get executed if the exception had not occurred? Yes.
What’s the C# equivalent of C++ catch (…), which was a catch-all statement for any possible exception? A catch block that catches the exception of type System.Exception. You can also omit the parameter data type in this case and just write catch {}.
Can multiple catch blocks be executed? No, once the proper catch code fires off, the control is transferred to the finally block (if there are any), and then whatever follows the finally block.
Why is it a bad idea to throw your own exceptions? Well, if at that point you know that an error has occurred, then why not write the proper code to handle that error instead of passing a new Exception object to the catch block? Throwing your own exceptions signifies some design flaws in the project.
What’s a delegate? A delegate object encapsulates a reference to a method. In C++ they were referred to as function pointers.
What’s a multicast delegate? It’s a delegate that points to and eventually fires off several methods.
How’s the DLL Hell problem solved in .NET? Assembly versioning allows the application to specify not only the library it needs to run (which was available under Win32), but also the version of the assembly.
What are the ways to deploy an assembly? An MSI installer, a CAB archive, and XCOPY command.
What’s a satellite assembly? When you write a multilingual or multi-cultural application in .NET, and want to distribute the core application separately from the localized modules, the localized assemblies that modify the core application are called satellite assemblies.
What namespaces are necessary to create a localized application? System.Globalization, System.Resources.
What’s the difference between // comments, /* */ comments and /// comments? Single-line, multi-line and XML documentation comments.
How do you generate documentation from the C# file commented properly with a command-line compiler? Compile it with a /doc switch.
What’s the difference between and XML documentation tag? Single line code example and multiple-line code example.
Is XML case-sensitive? Yes, so and are different elements.
What debugging tools come with the .NET SDK? CorDBG – command-line debugger, and DbgCLR – graphic debugger. Visual Studio .NET uses the DbgCLR. To use CorDbg, you must compile the original C# file using the /debug switch.
What does the This window show in the debugger? It points to the object that’s pointed to by this reference. Object’s instance data is shown.
What does assert() do? In debug compilation, assert takes in a Boolean condition as a parameter, and shows the error dialog if the condition is false. The program proceeds without any interruption if the condition is true.
What’s the difference between the Debug class and Trace class? Documentation looks the same. Use Debug class for debug builds, use Trace class for both debug and release builds.
Why are there five tracing levels in System.Diagnostics.TraceSwitcher? The tracing dumps can be quite verbose and for some applications that are constantly running you run the risk of overloading the machine and the hard drive there. Five levels range from None to Verbose, allowing to fine-tune the tracing activities.
Where is the output of TextWriterTraceListener redirected? To the Console or a text file depending on the parameter passed to the constructor.
How do you debug an ASP.NET Web application? Attach the aspnet_wp.exe process to the DbgClr debugger.
What are three test cases you should go through in unit testing? Positive test cases (correct data, correct output), negative test cases (broken or missing data, proper handling), exception test cases (exceptions are thrown and caught properly).
Can you change the value of a variable while debugging a C# application? Yes, if you are debugging via Visual Studio.NET, just go to Immediate window.
Explain the three services model (three-tier application). Presentation (UI), business (logic and underlying code) and data (from storage or other sources).
What are advantages and disadvantages of Microsoft-provided data provider classes in ADO.NET? SQLServer.NET data provider is high-speed and robust, but requires SQL Server license purchased from Microsoft. OLE-DB.NET is universal for accessing other sources, like Oracle, DB2, Microsoft Access and Informix, but it’s a .NET layer on top of OLE layer, so not the fastest thing in the world. ODBC.NET is a deprecated layer provided for backward compatibility to ODBC engines.
What’s the role of the DataReader class in ADO.NET connections? It returns a read-only dataset from the data source when the command is executed.
What is the wildcard character in SQL? Let’s say you want to query database with LIKE for all employees whose name starts with La. The wildcard character is %, the proper query with LIKE would involve ‘La%’.
Explain ACID rule of thumb for transactions. Transaction must be Atomic (it is one unit of work and does not dependent on previous and following transactions), Consistent (data is either committed or roll back, no “in-between” case where something has been updated and something hasn’t), Isolated (no transaction sees the intermediate results of the current transaction), Durable (the values persist if the data had been committed even if the system crashes right after).
What connections does Microsoft SQL Server support? Windows Authentication (via Active Directory) and SQL Server authentication (via Microsoft SQL Server username and passwords).
Which one is trusted and which one is untrusted? Windows Authentication is trusted because the username and password are checked with the Active Directory, the SQL Server authentication is untrusted, since SQL Server is the only verifier participating in the transaction.
Why would you use untrusted verificaion? Web Services might use it, as well as non-Windows applications.
What does the parameter Initial Catalog define inside Connection String? The database name to connect to.
What’s the data provider name to connect to Access database? Microsoft.Access.
What does Dispose method do with the connection object? Deletes it from the memory.
What is a pre-requisite for connection pooling? Multiple processes must agree that they will share the same connection, where every parameter is the same, including the security settings.



Interview Questions asp.net
2008-01-04T02:13:00.000-08:00
Interview Questions
ASP.NET
   
  1.    Describe the role of inetinfo.exe, aspnet_isapi.dll andaspnet_wp.exe in the page loading process. inetinfo.exe is theMicrosoft IIS server running, handling ASP.NET requests among other things.When an ASP.NET request is received (usually a file with .aspx extension),the ISAPI filter aspnet_isapi.dll takes care of it by passing the request tothe actual worker process aspnet_wp.exe. 
  2.    What’s the difference between Response.Write() andResponse.Output.Write()? The latter one allows you to write formattedoutput. 
  3.    What methods are fired during the page load? Init() - when the pageis instantiated, Load() - when the page is loaded into server memory,PreRender() - the brief moment before the page is displayed to the user asHTML, Unload() - when page finishes loading. 
  4.    Where does the Web page belong in the .NET Framework class hierarchy?System.Web.UI.Page 
  5.    Where do you store the information about the user’s locale? System.Web.UI.Page.Culture 
  6.    What’s the difference between Codebehind="MyCode.aspx.cs" andSrc="MyCode.aspx.cs"? CodeBehind is relevant to Visual Studio.NET only. 
  7.    What’s a bubbled event? When you have a complex control, like DataGrid, writing an event processing routine for each object (cell, button, row, etc.) is quite tedious. The controls can bubble up their eventhandlers, allowing the main DataGrid event handler to take care of its constituents. 
  8.    Suppose you want a certain ASP.NET function executed on MouseOver overa certain button. Where do you add an event handler? It’s the Attributesproperty, the Add function inside that property. So btnSubmit.Attributes.Add("onMouseOver","someClientCode();") 
  9.    What data type does the RangeValidator control support? Integer,String and Date.
  10.                Explain the differences between Server-side and Client-side code?  Server-side code runs on the server. Client-side code runs in the clients’ browser.
  11.                What type of code (server or client) is found in a Code-Behind class? Server-side code.
  12.                Should validation (did the user enter a real date) occur server-side or client-side? Why? Client-side. This reduces an additional request to the server to validate the users input.
  13.                What does the "EnableViewState" property do? Why would I want it on or off?  It enables the viewstate on the page. It allows the page to save the users input on a form.
  14.                What is the difference between Server.Transfer and Response.Redirect? Why would I choose one over the other? Server.Transfer is used to post a form to another page. Response.Redirect is used to redirect the user to another page or site.
  15.                Can you explain the difference between an ADO.NET Dataset and an ADO Recordset? 
  ·         A DataSet can represent an entire relational database in memory, complete with tables, relations, and views. 
  ·         A DataSet is designed to work without any continuing connection to the original data source. 
  ·         Data in a DataSet is bulk-loaded, rather than being loaded on demand. 
  ·         There's no concept of cursor types in a DataSet. 
  ·         DataSets have no current record pointer You can use For Each loops to move through the data. 
  ·         You can store many edits in a DataSet, and write them to the original data source in a single operation. 
  ·         Though the DataSet is universal, other objects in ADO.NET come in different versions for different data sources. 
  16.                Can you give an example of what might be best suited to place in the Application_Start and Session_Start subroutines?  This is where you can set the specific variables for the Application and Session objects.
  17.                If I’m developing an application that must accommodate multiple security levels though secure login and my ASP.NET web application is spanned across three web-servers (using round-robin load balancing) what would be the best approach to maintain login-in state for the users? Maintain the login state security through a database.
  18.                Can you explain what inheritance is and an example of when you might use it? When you want to inherit (use the functionality of) another class. Base Class Employee. A Manager class could be derived from the Employee base class.
  19.                Whats an assembly?  Assemblies are the building blocks of the .NET framework. Overview of assemblies from MSDN
  20.                Describe the difference between inline and code behind. Inline code written along side the html in a page. Code-behind is code written in a separate file and referenced by the .aspx page.
  21.                Explain what a diffgram is, and a good use for one? The DiffGram is one of the two XML formats that you can use to render DataSet object contents to XML. For reading database data to an XML file to be sent to a Web Service.
  22.                Whats MSIL, and why should my developers need an appreciation of it if at all? MSIL is the Microsoft Intermediate Language. All .NET compatible languages will get converted to MSIL.
  23.                Which method do you invoke on the DataAdapter control to load your generated dataset with data? The .Fill() method
  24.                Can you edit data in the Repeater control?  No, it just reads the information from its data source
  25.                Which template must you provide, in order to display data in a Repeater control? ItemTemplate
  26.                How can you provide an alternating color scheme in a Repeater control? Use the AlternatingItemTemplate
  27.                What property must you set, and what method must you call in your code, in order to bind the data from some data source to the Repeater control? You must set the DataSource property and call the DataBind method.
  28.                What base class do all Web Forms inherit from?  The Page class.
  29.                Name two properties common in every validation control? ControlToValidate property and Text property.
  30.                What tags do you need to add within the asp:datagrid tags to bind columns manually? Set AutoGenerateColumns Property to false on the datagrid tag
  31.                What tag do you use to add a hyperlink column to the DataGrid? 
  32.                What is the transport protocol you use to call a Web service? SOAP is the preferred protocol. 
  33.                True or False: A Web service can only be written in .NET? False
  34.                What does WSDL stand for? (Web Services Description Language)
  35.                Where on the Internet would you look for Web services? (http://www.uddi.org)
  36.                Which property on a Combo Box do you set with a column name, prior to setting the DataSource, to display data in the combo box? DataTextField property 
  37.                Which control would you use if you needed to make sure the values in two different controls matched?  CompareValidator Control
  38.                True or False: To test a Web service you must create a windows application or Web application to consume this service? False, the webservice comes with a test page and it provides HTTP-GET method to test.
  39.                How many classes can a single .NET DLL contain?  It can contain many classes.