System.Web.HttpApplication Class

Defines the methods, properties, and events that are common to all application objects in an ASP.NET application. This class is the base class for applications that are defined by the user in the Global.asax file.

See Also: HttpApplication Members


public class HttpApplication : System.ComponentModel.IComponent, IHttpAsyncHandler


Instances of the System.Web.HttpApplication class are created in the ASP.NET infrastructure, not by the user directly. One instance of the System.Web.HttpApplication class is used to process many requests in its lifetime. However, it can process only one request at a time. Thus, member variables can be used to store per-request data.

An application raises events that can be handled by custom modules that implement the System.Web.IHttpModule interface or by event handler code that is defined in the Global.asax file. Custom modules that implement the System.Web.IHttpModule interface can be put in the App_Code folder or in a DLL in the Bin folder.

System.Web.HttpApplication is introduced in the .NET Framework version 3.5. For more information, see The .NET Framework 3.5 Architecture.


When running IISĀ 7.0 in Integrated mode, custom modules in the App_Code folder or Bin folder apply to all requests in the request pipeline. Event handler code in the Global.asax file only applies to requests that are mapped to an ASP.NET handler.

The application events are raised in the following order:

[The 'ordered' type of list has not been implemented in the ECMA stylesheet.]


Namespace: System.Web
Assembly: System.Web (in System.Web.dll)
Assembly Versions: 1.0.5000.0,