HttpReceiveRequestEntityBody 使用应注意的地方

如果EntityBody数据很大，调用此函数是不能完全接收全部数据的，我们不能简单的判断

BYTE* pBuffer = new BYTE[4096];
ZeroMemory(pBuffer, 4096);
string entityData;
DWORD dwReceived = 0;
if((NO_ERROR == HttpReceiveRequestEntityBody(reqQueueHandle, requestId, 0, pBuffer, 4096, &dwReceived, NULL)) && dwReceived > 0) {
    entityData += pBuffer;
}
delete[] pBuffer;

就认为已经接受了全部的数据，根据PlatformSDK的注释:

Remarks
To retrieve an entire entity body, an application is expected to call HttpReceiveRequestEntityBody, passing in new buffers, until the function returns ERROR_HANDLE_EOF. As long as a buffer full of entity-body data is copied successfully and there is still more entity-body data waiting to be retrieved, the function returns NO_ERROR. 

我们应该这样做

BYTE* pBuffer = new BYTE[4096];
ZeroMemory(pBuffer, 4096);
string entityData;
DWORD dwReceived = 0;
while((ERROR_HANDLE_EOF != HttpReceiveRequestEntityBody(reqQueueHandle, requestId, 0, pBuffer, 4096, &dwReceived, NULL)) && (dwReceived > 0)) {
    entityData += pBuffer;
    ZeroMemory(pBuffer, 4096);
}
delete[] pBuffer;