How to register a custom HTTP module in your .NET web application

You can easily add your custom HTTP module to a .NET web application. Here’s an excerpt from the MSDN article referenced in the previous sentence:

“An HttpModule is an assembly that implements the IHttpModule interface and handles events. ASP.NET includes a set of HttpModules that can be used by your application.”

If you have a web application, e.g. an MVC or Web API (2) project then you can add a custom HTTP module as follows.

Add a class that implements the IHttpModule interface. Here’s an implementation stub which shows the 2 methods that need to be implemented:

namespace HttpModuleTestApplication.Modules
	public class TestModule : IHttpModule
		public void Dispose()
			throw new NotImplementedException();

		public void Init(HttpApplication context)
			throw new NotImplementedException();

The Init method initialises a module. You can sign up for events available in the incoming HttpApplication object. This page on MSDN lists all the available events which you can attach an event handler to. Some of them such as BeginRequest and RequestCompleted will sound familiar to all .NET web developers.

The Dispose method implementation is optional. It’s there for any resource cleanup, we’ll ignore it for this basic example.

Let’s sign up for two events:

namespace HttpModuleTestApplication.Modules
	public class TestModule : IHttpModule
		public void Dispose()

		public void Init(HttpApplication context)
			context.BeginRequest += context_BeginRequest;
			context.RequestCompleted += context_RequestCompleted;

		void context_RequestCompleted(object sender, EventArgs e)
			Debug.WriteLine("Context_RequestCompleted event fired.");

		void context_BeginRequest(object sender, EventArgs e)
			Debug.WriteLine("Context_BeginRequest event fired.");

The module needs to be registered. It can be added to the web.config file within the system.webServer node:

		<add name="DescriptiveNameOfModule"

We add the individual custom modules within the modules node. The add element has a name and a type property. Name can be pretty much anything so select a descriptive name. The type must be the fully qualified name of the module including the namespace and the class name.

If you run your web application you should see that the registered events will be fired.

View all various C# language feature related posts here.


About Andras Nemes
I'm a .NET/Java developer living and working in Stockholm, Sweden.

One Response to How to register a custom HTTP module in your .NET web application

Leave a Reply

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

You are commenting using your 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


A great site

Elliot Balynn's Blog

A directory of wonderful thoughts

Robin Sedlaczek's Blog

Developer on Microsoft Technologies

HarsH ReaLiTy

A Good Blog is Hard to Find

Softwarearchitektur in der Praxis

Wissenswertes zu Webentwicklung, Domain-Driven Design und Microservices

the software architecture

thoughts, ideas, diagrams,enterprise code, design pattern , solution designs

Technology Talks

on Microsoft technologies, Web, Android and others

Software Engineering

Web development

Disparate Opinions

Various tidbits

chsakell's Blog

Anything around ASP.NET MVC,WEB API, WCF, Entity Framework & AngularJS

Cyber Matters

Bite-size insight on Cyber Security for the not too technical.

Guru N Guns's

OneSolution To dOTnET.

Johnny Zraiby

Measuring programming progress by lines of code is like measuring aircraft building progress by weight.

%d bloggers like this: