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This page is specific to
Microsoft Visual Studio 2008/.NET Framework 3.5

Other versions are also available for the following:
IIS 7.0: IHttpContext::SetServerVariable Method

Sets a server variable to a specified value.

virtual HRESULT SetServerVariable(
   PCSTR pszVariableName,
   PCWSTR pszVariableValue
) = 0;
pszVariableName

[IN] A pointer to a string that contains the name of the server variable to set.

pszVariableValue

[IN] A pointer to a string that contains the value of the server variable to set.

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

Value

Description

S_OK

Indicates that the operation was successful.

ERROR_NOT_ENOUGH_MEMORY

Indicates that there is insufficient memory to perform the operation.

The SetServerVariable method specifies the values for Common Gateway Interface (CGI) server variables. The server variable specified by the pszVariableName parameter can be a custom variable or a variable defined in Request for Comments (RFC) 3875, "The Common Gateway Interface (CGI) Version 1.1."

NoteNote:

The server variable specified by the pszVariableName parameter is created if it does not exist.

The following code example demonstrates how to use the SetServerVariable method to create an HTTP module that sets the value of the SERVER_NAME server variable to an example value.

Visual C++
#define _WINSOCKAPI_
#include <windows.h>
#include <sal.h>
#include <httpserv.h>

// Create the module class.
class MyHttpModule : 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 request.
        IHttpRequest * pHttpRequest = pHttpContext->GetRequest();

        // Test for an error.
        if (pHttpRequest != NULL)
        {
            // Set the value of an example server variable.
            hr = pHttpContext->SetServerVariable("SERVER_NAME", L"Example Value");

            // Test for an error.
            if (FAILED(hr))
            {
                // Set the error status.
                pProvider->SetErrorStatus( 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 MyHttpModuleFactory : public IHttpModuleFactory
{
public:
    HRESULT
    GetHttpModule(
        OUT CHttpModule ** ppModule, 
        IN IModuleAllocator * pAllocator
    )
    {
        UNREFERENCED_PARAMETER( pAllocator );

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

        // 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 MyHttpModuleFactory,
        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 IIS 7.0: Walkthrough: Creating a Request-Level HTTP Module By Using Native Code.

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

Type

Description

Client

Requires IIS 7 on Windows Vista.

Server

Requires IIS 7 on Windows Vista.

Product

IIS 7

Header

Httpserv.h

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