How HttpHandlers work with Example

Watermarking PDF documents using HttpHandlers

Whenever we work with Httphandler we have to inherit IHttpHandler.
We will be unable to inherit IHttpHandler unless & until we add
System.web as references.
1>Create a class library with the name Handler














2>Rename the class1.cs with required Class and here it is PdfHandler.








3>Add IHttpHandler interface.If any problem occured just ad the
reference System.web from .Net tab listing.











4>Add ProcessRequest and IsReusable Method.












5>Download the iTextSharp.dll and add it to references so as to
pdf related function can work.
6>Build the class library.After successfully build dll will be
generated.
7>Create a new website TestPdfRender and add the binary output of
the custom handler as a reference.












8>Add the handler to the web.config.








9>To map the .pdf extension through IIS: within IIS,
right click on TestPdfRender->properties->under Directory tab,
click on configuration->add a new extension with extension .pdf
and set Executable to the .NET runtime
("c:\windows\microsoft.net\framework\v2.0.50727\aspnet_isapi.dll"),
keep the rest of the sections to their default values.
Click on OK to close all the open configuration windows.

Note:here IIS 6 have one error after selecting the dll atonce ok
button is not being enable.Just click on the executable text box ok
button is enable.














10>Now the application is ready for testing.open the default.aspx
and add this test hyperlink control:









11>Genereated output is.