ASP.NET interview questions: – Explain differences and how to write Httphandlers and HttpModules in ASP.NET

Handlers and modules helps you inject pre-processing logic before the ASP.NET request reaches the website.

One of the scenarios where you would like use them is, before request reaches on the server you would like to check if the user has authenticated or not.

Writing a Httphandler

  • Create a class and implement “IHttpHandler”.

public class clsHttpHandler : IHttpHandler
{

   public bool IsReusable
   {
      get { return true; }
   }

   public void ProcessRequest(HttpContext context)
   {
      // Put implementation here.
   }

}

  • Define implementation for “processrequest” method.
  • Register the class in web.config with file extension in httphandler tag.

<httpHandlers>
<add verb=”*” path=”*.gif” type=”clsHttpHandler”/>
</httpHandlers>

Writing an HttpModule

  • Create a class and implement IHttpModule interface.
  • Attach events with your methods and put implementation in those events as shown in the below code snippet.

public class clsHttpModule : IHttpModule
{

   public void Init(HttpApplication context)
   {
      this.httpApp = context;
      httpApp.Context.Response.Clear();
      httpApp.AuthenticateRequest += new EventHandler(OnAuthentication);
      httpApp.AuthorizeRequest += new EventHandler(OnAuthorization);
      httpApp.BeginRequest += new EventHandler(OnBeginrequest);
      httpApp.EndRequest += new EventHandler(OnEndRequest);
      httpApp.ResolveRequestCache += new EventH

   }
   void OnUpdateRequestCache(object sender, EventArgs a)
   {
     //Implementation
   }
   void OnReleaseRequestState(object sender, EventArgs a)
   {
     //Implementation
   }
   void OnPostRequestHandlerExecute(object sender, EventArgs a)
   {
     //Implementation
   }
   void OnPreRequestHandlerExecute(object sender, EventArgs a)
   {
     //Implementation
   }
   void OnAcquireRequestState(object sender, EventArgs a)
   {
     //Implementation
   }
   void OnResolveRequestCache(object sender, EventArgs a)
   {
     //Implementation
   }
   void OnAuthorization(object sender, EventArgs a)
   {
     //Implementation
   }
   void OnAuthentication(object sender, EventArgs a)
   {
     //Implementation
   }
   void OnBeginrequest(object sender, EventArgs a)
   {
     //Implementation
   }
   void OnEndRequest(object sender, EventArgs a)
   {
     //Implementation
   }

}

  • Register the class in web.config in httpmodule tag as shown in the below code snippet.

<httpModules>
<add name=”clsHttpModule” type=”clsHttpModule”/>
</httpModules>

Difference between Httphandlers and HttpModules

Httphandlers is an extension based processor. In other words the pre-processing logic is invoked depending on file extensions.

Httpmodule is an event based processor. In other words ASP.NET emits lot of event like BeginRequest, AuthenticateRequest etc, we can write login functionality in those events using Httpmodule.

Above is the ASP.NET interview questions and see following video on Postback, Ispostback and Autopostback:  –

Advertisements

About c# and .NET Interview questions

This blog is for developers who want to crack .NET and C# interviews. It has all tips and tricks needed to crack .NET interviews , C# interview , SQL Server interview , Java interview , WCF Interview , Silverlight interview , WPF interview , LINQ interview , Entity framework Interview. Do not forget to watch our Learn step by step video series. Learn MVC in 16 hours:- https://www.youtube.com/watch?v=Lp7nSImO5vk Learn AngularJS Step by Step:- https://www.youtube.com/watch?v=0kmdjqgO9IY Learn Design Pattern in 8 hours:- https://www.youtube.com/watch?v=YDobmucohqk Learn C# and .NET in 60 days:- https://www.youtube.com/watch?v=yh2SrzCkNQA Learn MSBI in 32 hours:- https://www.youtube.com/watch?v=mGPJx3ocFgg Learn SharePoint Step by Step in 8 hours:- https://youtu.be/C2fW76SwJNU
This entry was posted in Uncategorized and tagged , , , , , , . Bookmark the permalink.

One Response to ASP.NET interview questions: – Explain differences and how to write Httphandlers and HttpModules in ASP.NET

  1. Nileah says:

    Nice n simple explanation..

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s