WinHttpSendRequest 和 ERROR_WINHTTP_RESEND_REQUEST

Question

调用 WinHttpSendRequest 后 GetLastError() 是否可以 return ERROR_WINHTTP_RESEND_REQUEST？

WinHttpSendRequest 的文档：

ERROR_WINHTTP_RESEND_REQUEST
The application must call WinHttpSendRequest again due to a redirect or authentication challenge. Windows Server 2003 with SP1, Windows XP with SP2 and Windows 2000: This error is not supported.

但来自 MSDN 的示例（WinHTTP 中的身份验证）会在 WinHttpReceiveResponse 之后检查此值。

Answer 1

But samples from MSDN (Authentication in WinHTTP) checks for this value after WinHttpReceiveResponse.

乍一看 the sample 可能看起来像那样。但是如果你仔细观察，如果 either WinHttpSendRequest() or WinHttpReceiveResponse() 失败，样本实际上会检查 ERROR_WINHTTP_RESEND_REQUEST :

// Send a request.
bResults = WinHttpSendRequest( hRequest,
                               WINHTTP_NO_ADDITIONAL_HEADERS,
                               0,
                               WINHTTP_NO_REQUEST_DATA,
                               0, 
                               0, 
                               0 );

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

// Resend the request in case of 
// ERROR_WINHTTP_RESEND_REQUEST error.
if( !bResults && GetLastError( ) == ERROR_WINHTTP_RESEND_REQUEST)
    continue;

如果 WinHttpSendRequest() returns FALSE，将跳过对 WinHttpReceiveResponse() 的调用并检查 GetLastError() 以查找 ERROR_WINHTTP_RESEND_REQUEST。此代码位于 while 循环内，因此 continue 语句将导致跳过循环的剩余部分，因此将再次调用 WinHttpSendRequest()。

结论：样本符合参考文档

WinHttpSendRequest 和 ERROR_WINHTTP_RESEND_REQUEST

WinHttpSendRequest and ERROR_WINHTTP_RESEND_REQUEST

c

winapi

winhttp

getlasterror