This function adds one or more Hypertext Transfer Protocol (HTTP) request headers to the HTTP request handle.
At a Glance
| Header file: | Wininet.h |
| Windows CE versions: | 2.0 and later |
Syntax
BOOL WINAPI HttpAddRequestHeaders(
HINTERNET hHttpRequest, LPCTSTR lpszHeaders,
DWORD dwHeadersLength, DWORD dwModifiers);
Parameters
hHttpRequest
[in] Open HTTP request handle returned by HttpOpenRequest.
lpszHeaders
[in] Long pointer to the null-terminated strings that contains headers to append to the request. Each header must be terminated by a CR/LF (carriage return/line feed) pair.
dwHeadersLength
[in] Specifies the length, in characters, of lpszHeaders. If this parameter is -1L, the function assumes that lpszHeaders is zero-terminated (ASCIIZ), and the length is computed.
dwModifiers
[in] Specifies the values used to modify the semantics of this function. Can be a combination of the following values:
| Value | Description |
| HTTP_ADDREQ_FLAG_ADD | Adds the header if it does not exist. Used with HTTP_ADDREQ_FLAG_REPLACE. |
| HTTP_ADDREQ_FLAG_ADD_IF_NEW | Adds the header only if it does not already exist; otherwise, an error is returned. |
| HTTP_ADDREQ_FLAG_COALESCE | Coalesces headers of the same name. |
| HTTP_ADDREQ_FLAG_COALESCE_WITH_COMMA | Coalesces headers of the same name. For example, adding "Accept: text/*" followed by "Accept: audio/*" with this flag results in the formation of the single header "Accept: text/*, audio/*". This causes the first header found to be coalesced. It is up to the calling application to ensure a cohesive scheme with respect to coalesced/separate headers. |
| HTTP_ADDREQ_FLAG_COALESCE_WITH_SEMICOLON | Coalesces headers of the same name using a semicolon. |
| HTTP_ADDREQ_FLAG_REPLACE | Replaces or removes a header. If the header value is empty and the header is found, it is removed. If not empty, the header value is replaced. |
Return Values
TRUE indicates success. FALSE indicates failure. To get extended error information, call GetLastError.
Remarks
HttpAddRequestHeaders appends additional, free-format headers to the HTTP request handle and is intended for use by sophisticated clients that need detailed control over the exact request sent to the HTTP server.
Note that for basic HttpAddRequestHeaders, the application can pass in multiple headers in a single buffer. If the application is trying to remove or replace a header, only one header can be supplied in lpszHeaders.
See Also