Before we can see this handler in action, we need to wire up
the web configuration file. This file can be found in the root of your web
application project or web site. In this file is an HttpHandler section. It
contains the information related to these handlers. We need to define ours in
here. The important information is the fully-qualified name of our
HttpHandler's type. This means the full namespace followed by the class name.
In our case this is RollYourOwnHttpHandler.SimpleHandler.
We also need to include the name of the assembly where the handler resides. I
named it RollYourOwnHttpHandler, which happens to
also be the namespace.
The verb we define as * means that we want this handler to
take care of all of the different actions for these. This means it will handle
everything including gets and posts. We define a path which we want to handle.
The * is a wildcard so we want to handle any request whose path ends in .hello;
so we have effectively created a fake file extension here for this handler. The
type attribute uses the other information we discussed, the fully-qualified
name of our HttpHandler type followed by a comma and then the name of the
assembly.
Listing 5: Configuration
<configuration>
<!--Other config information here-->
<system.web>
<!--Other config information here-->
<httpModules>
<add verb="*" path="*.hello"
type="RollYourOwnHttpHandler.SimpleHandler, RollYourOwnHttpHandler"/>
</httpModules>
<!--Other config information here-->
</system.web>
<!--Other config information here-->
</configuration>
If we use a path of "*.aspx" then our handler will
intercept asp.net's normal traffic. This gives us some neat functionality. We
just need to make sure that at the end of our ProcessRequest method we pass
control back over to the standard ASP.NET handler or we will have eliminated
our normal ASP.NET traffic.
Configuring IIS Application Extensions (optional)
If you are using a path which is not normally mapped to
ASP.NET, you will need to let IIS know that it needs to send the traffic to be
handled by ASP.NET. This does not need to be done for the development server
built into Visual Studio. So if you are running in Visual Studio, this task is
not necessary until you are going to deploy this to a server running IIS.
Launch IIS and right click on the web site you are using.
Select Properties. In this window navigate to the tab labeled Home Directory.
Click on the Configuration button. This will open up the Application
Configuration window. We need to add another application extension, so click on
the Add button. The Executable should be the file path of aspnet_isapi.dll,
which can be found in your .NET Framework directory. This will vary based on
your operating system as well as the version of the .NET framework you are
using. The Extension should be the extension you want to map; in our case it is
the .hello extension.
