HTTP modules 和 HTTP handlers
HTTP modules are classes that can be configured to run in response to events that fire during the request for an ASP.NET resource.
An HTTP handler is a class that is responsible for rendering a particular resource, or a particular type of resource.
In fact, each time you add an ASP.NET Web page to your project, you are essentially writing a HTTP handler. This is because when the HTML portion of an ASP.NET Web page gets dynamically compiled at run time, it directly or indirectly inherits from
下图显示了用户请求与HTTP Modules和HTTP Handler的交互过程，可以自己编写HTTP Modules和Handler，以便每次调用页面时，都能够执行相应的功能。如果要使用自己编写的Handler和Modules必须在Web.Config中进行相应的设置，详细可参考Using HTTP Modules and Handlers to Create Pluggable ASP.NET Components
An HTTP handler is a class that is responsible for rendering a particular resource, or a particular type of resource.
In fact, each time you add an ASP.NET Web page to your project, you are essentially writing a HTTP handler. This is because when the HTML portion of an ASP.NET Web page gets dynamically compiled at run time, it directly or indirectly inherits from
System.Web.UI.Page, which happens to be a HTTP handler implementation.下图显示了用户请求与HTTP Modules和HTTP Handler的交互过程，可以自己编写HTTP Modules和Handler，以便每次调用页面时，都能够执行相应的功能。如果要使用自己编写的Handler和Modules必须在Web.Config中进行相应的设置，详细可参考Using HTTP Modules and Handlers to Create Pluggable ASP.NET Components
