IHttpContext::ReleaseClonedContext Method

IIS 7.0

Releases a cloned IHttpContext instance.

virtual HRESULT ReleaseClonedContext(
) = 0;

This method takes no parameters.

An HRESULT. Possible values include, but are not limited to, those in the following table.




Indicates that the operation was successful.


Indicates that the parent context for the current request is not valid (for example, a child context is being released after the parent has been released).

The ReleaseClonedContext method releases an instance of an IHttpContext interface. For example, if you create a child context by using the IHttpContext::CloneContext method, you would call the child's ReleaseClonedContext method to release the child context when you are finished using it.


Calling the ReleaseClonedContext method to release a child request after releasing its parent context will return ERROR_INVALID_PARAMETER. For example, if you create a child context and then use that child to create a nested child request, you will need to release the child contexts in reverse-order of their creation.


The following code example demonstrates how to create an HTTP module that performs the following tasks:

  1. The module registers for the RQ_MAP_PATH notification.

  2. The module creates a CHttpModule class that contains OnMapPath and OnAsyncCompletion methods.

  3. When a Web client requests a URL, IIS calls the module's OnMapPath method. This method performs the following tasks:

    1. Tests to see whether the URL for the current request has a trailing slash or ends with /default.aspx. If the URL ends with either element, the module uses the IHttpContext::CloneContext method to create a clone of the current request.

    2. Calls the clone's IHttpRequest::SetUrl method to set the URL for the clone to /example/default.aspx.

    3. Calls the IHttpContext::ExecuteRequest method to execute the child request.

    4. Tests for asynchronous completion. If asynchronous completion is pending, the module returns processing to the integrated request-processing pipeline. If not, the module releases the cloned context.

  4. If asynchronous completion is required, IIS calls the module's OnAsyncCompletion method. This method releases the cloned context.

  5. The module removes the CHttpModule class from memory and then exits.

Your module must export the RegisterModule function. You can export this function by creating a module definition (.def) file for your project, or you can compile the module by using the /EXPORT:RegisterModule switch. For more information, see Walkthrough: Creating a Request-Level HTTP Module By Using Native Code.

You can optionally compile the code by using the __stdcall (/Gz) calling convention instead of explicitly declaring the calling convention for each function.





  • IIS 7.0 on Windows Vista

  • IIS 7.5 on Windows 7

  • IIS 8.0 on Windows 8

  • IIS 10.0 on Windows 10


  • IIS 7.0 on Windows Server 2008

  • IIS 7.5 on Windows Server 2008 R2

  • IIS 8.0 on Windows Server 2012

  • IIS 8.5 on Windows Server 2012 R2

  • IIS 10.0 on Windows Server 2016 Technical Preview


  • IIS 7.0, IIS 7.5, IIS 8.0, IIS 8.5, IIS 10.0

  • IIS Express 7.5, IIS Express 8.0, IIS Express 10.0