HttpHandler Not Working

ScottMacMaster used Ask the Experts™
I've never setup a HttpHandler before. What've I done isn't working. Can someone help? The following is what I've done.

1. Created a ClassLibrary project called TestHandler.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Web;

namespace TestHandler
    public class TestHandler : IHttpHandler
        public void ProcessRequest(System.Web.HttpContext context)

        public bool IsReusable{get {return true;}}

End Class

2. Copied the .dll into c:/windows/system32/inetsrv/

3. Added a virtual directory to the web site

I named it TestHandler.

4. Added .test extension to web app.

Went into the properties for the web app. Under Virtual Directory/Application settings I went into Configuration. The added an extension. I selected my dll, typed in .test, selected All Verbs.  This will eventually be used to process images so I think I'll only need to use GET.

5. Referenced the dll in a web.config file.

I created an empty web project to create a default web.config file. Then, I added a httphandler to it.

            <add verb="*" path="*.test" type="TestHandler, TestHandler.TestHandler " validate="true"/>

I then copied the web.config file to the folder for the web app.

6. Tested it

I created an empty file named test.test.

I then tried to open the file in my web browser. My browser gave the error "The Page Cannot Be Found"

The url to the test page is,

You can change .test to .html to see the test web page I have their.

Can someone help me get this working?
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1st. the file that you select when you add that .test extention should be:

2. You need to uncheck the "Verify File Exists" option when you added the extention

3. The dll should be in the bin folder.


Thanks, I missed that detail about mapping the extension to ASP.NET when I was looking at some references I found on the internet.

What's the reason for unchecking "Verify File Exists"?

I created a bin folder and put my dll in it.  That got it working.  I assume that ASP.NET looks there by default for assemblies?


Yes, by default it looks in the bin

Additionally, you didn't need to add this to the extension path? "c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\aspnet_isapi.dll"

Verify if file exists means to verify if there is a physical file there

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