| title | IHttpRequest::GetHeader Method |
|---|---|
| description | The IHttpRequest::GetHeader method returns the value of a specified HTTP header. |
| ms.date | 10/07/2016 |
| ms.assetid | be6a7069-7be4-6bdc-046e-29db7ab27b1b |
Returns the value of a specified HTTP header.
virtual PCSTR GetHeader(
IN PCSTR pszHeaderName,
OUT USHORT* pcchHeaderValue = NULL
) const = 0;
virtual PCSTR GetHeader(
IN HTTP_HEADER_ID ulHeaderIndex,
OUT USHORT* pcchHeaderValue = NULL
) const = 0; pszHeaderName
[IN] A pointer to a string that contains the name of the header to return.
ulHeaderIndex
[IN] The ID of the HTTP header to return.
pcchHeaderValue
[OUT] A pointer to an unsigned long integer that receives the length of the returned header value.
A pointer to a string that contains the specified header, or 0 if the header was not found.
The GetHeader method returns the value of an HTTP header for the current request. There are two overloaded versions of the GetHeader method. One specifies the header by using a string that is contained in the pszHeaderName parameter. The other overload uses an unsigned long integer that is contained in the ulHeaderIndex parameter. After you call the GetHeader method, the pcchHeaderValue parameter will contain the length, in characters, of the header value, not including the terminating character. pcchHeaderValue will be 0 if the header is not found.
The header name specified by the pszHeaderName parameter can be a custom header or a header defined in Request for Comments (RFC) 1945, "Hypertext Transfer Protocol -- HTTP/1.0," or RFC 2616, "Hypertext Transfer Protocol -- HTTP/1.1.
Note
The pszHeaderName parameter cannot be set to null.
The ulHeaderIndex parameter specifies the ID of an HTTP header that is listed in the HTTP_HEADER_ID enumeration.
Note
The HTTP_HEADER_ID enumeration is defined in the Http.h header file.
The following code example demonstrates how to use both versions of the GetHeader method to create an HTTP module that retrieves the User-Agent and Accept-Language HTTP headers for the request.
[!code-cppIHttpRequestGetHeader#1]
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 [!INCLUDEwinvista] - IIS 7.5 on Windows 7 - IIS 8.0 on Windows 8 - IIS 10.0 on Windows 10 |
| Server | - IIS 7.0 on [!INCLUDEwinsrv2008] - 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 |
| Product | - IIS 7.0, IIS 7.5, IIS 8.0, IIS 8.5, IIS 10.0 - [!INCLUDEiisexp75], [!INCLUDEiisexp80], [!INCLUDEiisexp100] |
| Header | Httpserv.h |
IHttpRequest Interface
IHttpRequest::DeleteHeader Method
IHttpRequest::SetHeader Method