WinHttpReceiveResponse function (winhttp.h)

Article
10/13/2021

The WinHttpReceiveResponse function waits to receive the response to an HTTP request initiated by WinHttpSendRequest. When WinHttpReceiveResponse completes successfully, the status code and response headers have been received and are available for the application to inspect using WinHttpQueryHeaders. An application must call WinHttpReceiveResponse before it can use WinHttpQueryDataAvailable and WinHttpReadData to access the response entity body (if any).

Syntax

WINHTTPAPI BOOL WinHttpReceiveResponse(
  [in] HINTERNET hRequest,
  [in] LPVOID    lpReserved
);

Parameters

[in] hRequest

HINTERNET handle returned by WinHttpOpenRequest and sent by WinHttpSendRequest. Wait until WinHttpSendRequest has completed for this handle before calling WinHttpReceiveResponse.

[in] lpReserved

This parameter is reserved and must be NULL.

Return value

Returns TRUE if successful, or FALSE otherwise. For extended error information, call GetLastError. Among the error codes returned are the following.

Error Code	Description
ERROR_WINHTTP_CANNOT_CONNECT	Returned if connection to the server failed.
ERROR_WINHTTP_CHUNKED_ENCODING_HEADER_SIZE_OVERFLOW	Returned when an overflow condition is encountered in the course of parsing chunked encoding.
ERROR_WINHTTP_CLIENT_AUTH_CERT_NEEDED	Returned when the server requests client authentication.
ERROR_WINHTTP_CONNECTION_ERROR	The connection with the server has been reset or terminated, or an incompatible SSL protocol was encountered. For example, WinHTTP version 5.1 does not support SSL2 unless the client specifically enables it.
ERROR_WINHTTP_HEADER_COUNT_EXCEEDED	Returned when a larger number of headers were present in a response than WinHTTP could receive.
ERROR_WINHTTP_HEADER_SIZE_OVERFLOW	Returned by WinHttpReceiveResponse when the size of headers received exceeds the limit for the request handle.
ERROR_WINHTTP_INCORRECT_HANDLE_STATE	The requested operation cannot be carried out because the handle supplied is not in the correct state.
ERROR_WINHTTP_INCORRECT_HANDLE_TYPE	The type of handle supplied is incorrect for this operation.
ERROR_WINHTTP_INTERNAL_ERROR	An internal error has occurred.
ERROR_WINHTTP_INVALID_SERVER_RESPONSE	The server response could not be parsed.
ERROR_WINHTTP_INVALID_URL	The URL is invalid.
ERROR_WINHTTP_LOGIN_FAILURE	The login attempt failed. When this error is encountered, the request handle should be closed with WinHttpCloseHandle. A new request handle must be created before retrying the function that originally produced this error.
ERROR_WINHTTP_NAME_NOT_RESOLVED	The server name could not be resolved.
ERROR_WINHTTP_OPERATION_CANCELLED	The operation was canceled, usually because the handle on which the request was operating was closed before the operation completed.
ERROR_WINHTTP_REDIRECT_FAILED	The redirection failed because either the scheme changed or all attempts made to redirect failed (default is five attempts).
ERROR_WINHTTP_RESEND_REQUEST	The WinHTTP function failed. The desired function can be retried on the same request handle.
ERROR_WINHTTP_RESPONSE_DRAIN_OVERFLOW	Returned when an incoming response exceeds an internal WinHTTP size limit.
ERROR_WINHTTP_SECURE_FAILURE	One or more errors were found in the Secure Sockets Layer (SSL) certificate sent by the server. To determine what type of error was encountered, check for a WINHTTP_CALLBACK_STATUS_SECURE_FAILURE notification in a status callback function. For more information, see WINHTTP_STATUS_CALLBACK.
ERROR_WINHTTP_TIMEOUT	The request has timed out.
ERROR_WINHTTP_UNRECOGNIZED_SCHEME	The URL specified a scheme other than "http:" or "https:".
ERROR_NOT_ENOUGH_MEMORY	Not enough memory was available to complete the requested operation. (Windows error code)

Remarks

Even when WinHTTP is used in asynchronous mode (that is, when WINHTTP_FLAG_ASYNC has been set in WinHttpOpen), this function can operate either synchronously or asynchronously. If this function returns FALSE, this function failed and you can call GetLastError to get extended error information. If this function returns TRUE, the application should expect either the WINHTTP_CALLBACK_STATUS_HEADERS_AVAILABLE completion callback, indicating success, or the WINHTTP_CALLBACK_STATUS_REQUEST_ERROR completion callback, indicating that the operation completed asynchronously, but failed.

If a status callback function has been installed with WinHttpSetStatusCallback, then those of the following notifications that have been set in the dwNotificationFlags parameter of WinHttpSetStatusCallback indicate progress in receiving the response:

WINHTTP_CALLBACK_STATUS_RECEIVING_RESPONSE
WINHTTP_CALLBACK_STATUS_RESPONSE_RECEIVED
WINHTTP_CALLBACK_STATUS_HEADERS_AVAILABLE
WINHTTP_CALLBACK_STATUS_INTERMEDIATE_RESPONSE
WINHTTP_CALLBACK_STATUS_REDIRECT

If the server closes the connection, the following notifications will also be reported, provided that they have been set in the dwNotificationFlags parameter of WinHttpSetStatusCallback:

WINHTTP_CALLBACK_STATUS_CLOSING_CONNECTION
WINHTTP_CALLBACK_STATUS_CONNECTION_CLOSED

Note For Windows XP and Windows 2000, see the Run-Time Requirements section of the WinHttp start page.

Examples

This example shows code that writes data to an HTTP server. The server name supplied in the example, www.wingtiptoys.com, is fictitious and must be replaced with the name of a server for which you have write access.

    LPSTR pszData = "WinHttpWriteData Example";
    DWORD dwBytesWritten = 0;
    BOOL  bResults = FALSE;
    HINTERNET hSession = NULL,
              hConnect = NULL,
              hRequest = NULL;

    // Use WinHttpOpen to obtain a session handle.
    hSession = WinHttpOpen(  L"A WinHTTP Example Program/1.0", 
                             WINHTTP_ACCESS_TYPE_DEFAULT_PROXY,
                             WINHTTP_NO_PROXY_NAME, 
                             WINHTTP_NO_PROXY_BYPASS, 0);

    // Specify an HTTP server.
    if (hSession)
        hConnect = WinHttpConnect( hSession, L"www.wingtiptoys.com",
                                   INTERNET_DEFAULT_HTTP_PORT, 0);

    // Create an HTTP Request handle.
    if (hConnect)
        hRequest = WinHttpOpenRequest( hConnect, L"PUT", 
                                       L"/writetst.txt", 
                                       NULL, WINHTTP_NO_REFERER, 
                                       WINHTTP_DEFAULT_ACCEPT_TYPES, 
                                       0);

    // Send a Request.
    if (hRequest) 
        bResults = WinHttpSendRequest( hRequest, 
                                       WINHTTP_NO_ADDITIONAL_HEADERS,
                                       0, WINHTTP_NO_REQUEST_DATA, 0, 
                                       (DWORD)strlen(pszData), 0);

    // Write data to the server.
    if (bResults)
        bResults = WinHttpWriteData( hRequest, pszData, 
                                     (DWORD)strlen(pszData), 
                                     &dwBytesWritten);

    // End the request.
    if (bResults)
        bResults = WinHttpReceiveResponse( hRequest, NULL);

    // Report any errors.
    if (!bResults)
        printf("Error %d has occurred.\n",GetLastError());


    // Close any open handles.
    if (hRequest) WinHttpCloseHandle(hRequest);
    if (hConnect) WinHttpCloseHandle(hConnect);
    if (hSession) WinHttpCloseHandle(hSession);

Requirements

Requirement	Value
Minimum supported client	Windows XP, Windows 2000 Professional with SP3 [desktop apps only]
Minimum supported server	Windows Server 2003, Windows 2000 Server with SP3 [desktop apps only]
Target Platform	Windows
Header	winhttp.h
Library	Winhttp.lib
DLL	Winhttp.dll
Redistributable	WinHTTP 5.0 and Internet Explorer 5.01 or later on Windows XP and Windows 2000.