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CHttpModule::Dispose Method

IIS 7.0

Releases all resources used by the current instance of the CHttpModule class.

virtual VOID Dispose(
   VOID
);

This method takes no parameters.

IIS automatically calls the Dispose method at the end of the request.

NoteNote:

Typically you create a class that is derived from CHttpModule by using the C++ new operator. Classes that were created with the new operator do not need to implement the Dispose method to perform any cleanup at the end of the request.

The following example demonstrates how to create a simple "Hello World" HTTP module. The module defines an exported RegisterModule function that passes an instance of an IHttpModuleFactory interface to the IHttpModuleRegistrationInfo::SetRequestNotifications method and registers for the RQ_BEGIN_REQUEST notification. IIS uses the IHttpModuleFactory::GetHttpModule method to create an instance of a CHttpModule class and returns a success status. IIS also uses the IHttpModuleFactory::Terminate method to remove the factory from memory.

When an RQ_BEGIN_REQUEST notification occurs, IIS calls the module's CHttpModule::OnBeginRequest method to process the current request. OnBeginRequest clears the response buffer and modifies the MIME type for the response. The method then creates a data chunk that contains a "Hello World" string and returns the string to a Web client. Finally, the module returns RQ_NOTIFICATION_FINISH_REQUEST to notify IIS that all notifications are finished and then exits.

#define _WINSOCKAPI_
#include <windows.h>
#include <sal.h>
#include <httpserv.h>

// Create the module class.
class CHelloWorld : public CHttpModule
{
public:
    REQUEST_NOTIFICATION_STATUS
    OnBeginRequest(
        IN IHttpContext * pHttpContext,
        IN IHttpEventProvider * pProvider
    )
    {
        UNREFERENCED_PARAMETER( pProvider );

        // Create an HRESULT to receive return values from methods.
        HRESULT hr;

        // Retrieve a pointer to the response.
        IHttpResponse * pHttpResponse = pHttpContext->GetResponse();

        // Test for an error.
        if (pHttpResponse != NULL)
        {
            // Clear the existing response.
            pHttpResponse->Clear();
            // Set the MIME type to plain text.
            pHttpResponse->SetHeader(
                HttpHeaderContentType,"text/plain",
                (USHORT)strlen("text/plain"),TRUE);

            // Create a string with the response.
            PCSTR pszBuffer = "Hello World!";
            // Create a data chunk.
            HTTP_DATA_CHUNK dataChunk;
            // Set the chunk to a chunk in memory.
            dataChunk.DataChunkType = HttpDataChunkFromMemory;
            // Buffer for bytes written of data chunk.
            DWORD cbSent;

            // Set the chunk to the buffer.
            dataChunk.FromMemory.pBuffer =
                (PVOID) pszBuffer;
            // Set the chunk size to the buffer size.
            dataChunk.FromMemory.BufferLength =
                (USHORT) strlen(pszBuffer);
            // Insert the data chunk into the response.
            hr = pHttpResponse->WriteEntityChunks(
                &dataChunk,1,FALSE,TRUE,&cbSent);

            // Test for an error.
            if (FAILED(hr))
            {
                // Set the HTTP status.
                pHttpResponse->SetStatus(500,"Server Error",0,hr);
            }

            // End additional processing.
            return RQ_NOTIFICATION_FINISH_REQUEST;
        }

        // Return processing to the pipeline.
        return RQ_NOTIFICATION_CONTINUE;
    }
};

// Create the module's class factory.
class CHelloWorldFactory : public IHttpModuleFactory
{
public:
    HRESULT
    GetHttpModule(
        OUT CHttpModule ** ppModule, 
        IN IModuleAllocator * pAllocator
    )
    {
        UNREFERENCED_PARAMETER( pAllocator );

        // Create a new instance.
        CHelloWorld * pModule = new CHelloWorld;

        // Test for an error.
        if (!pModule)
        {
            // Return an error if the factory cannot create the instance.
            return HRESULT_FROM_WIN32( ERROR_NOT_ENOUGH_MEMORY );
        }
        else
        {
            // Return a pointer to the module.
            *ppModule = pModule;
            pModule = NULL;
            // Return a success status.
            return S_OK;
        }            
    }

    void
    Terminate()
    {
        // Remove the class from memory.
        delete this;
    }
};

// Create the module's exported registration function.
HRESULT
__stdcall
RegisterModule(
    DWORD dwServerVersion,
    IHttpModuleRegistrationInfo * pModuleInfo,
    IHttpServer * pGlobalInfo
)
{
    UNREFERENCED_PARAMETER( dwServerVersion );
    UNREFERENCED_PARAMETER( pGlobalInfo );

    // Set the request notifications and exit.
    return pModuleInfo->SetRequestNotifications(
        new CHelloWorldFactory,
        RQ_BEGIN_REQUEST,
        0
    );
}


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.

Type

Description

Client

  • IIS 7.0 on Windows Vista

  • IIS 7.5 on Windows 7

  • IIS Express 7.5 on Windows XP, Windows Vista, Windows 7

  • IIS 8.0 on Windows 8 Client

Server

  • IIS 7.0 on Windows Server 2008

  • IIS 7.5 on Windows Server 2008 R2

  • IIS Express 7.5 on Windows Server 2003, Windows Server 2008, Windows Server 2008 R2

  • IIS 8.0 on Windows Server 2012

Product

IIS 7.0, IIS 7.5, IIS Express 7.5, IIS 8.0

Header

Httpserv.h

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