ASP.NET Interview Questions on HTTP modules and HTTP Handlers

What is the interface that you have to implement if you have to create a Custom HTTP Handler?
Implement IHttpHandler interface to create a synchronous handler.
Implement IHttpAsyncHandler to create an asynchronous handler

Which class is responsible for receiving and forwarding a request to the appropriate HTTP handler?
IHttpHandlerFactory Class

Can you create your own custom HTTP handler factory class?Yes, we can create a custom HTTP handler factory class by creating a class that implements the IHttpHandlerFactory interface.

What is the use of HTTP modules?
HTTP modules are used to implement various application features, such as forms authentication, caching, session state, and client script services.

What is the difference between HTTP modules and HTTP handlers?An HTTP handler returns a response to a request that is identified by a file name extension or family of file name extensions. In contrast, an HTTP module is invoked for all requests and responses. It subscribes to event notifications in the request pipeline and lets you run code in registered event handlers. The tasks that a module is used for are general to an application and to all requests for resources in the application.

What is the common way to register an HTTP module?The common way to register an HTTP module is to have an entry in the application's Web.config file.

Much of the functionality of a module can be implemented in a global.asax file. When do you create an HTTP module over using Global.asax File?
You create an HTTP module over using Global.asax file if the following conditions are true

1. You want to re-use the module in other applications.
2. You want to avoid putting complex code in the Global.asax file.
3. The module applies to all requests in the pipeline.