Keshav Nair.
try to this code:
CHAR postData[1024];
CHAR postData2[1024];
ZeroMemory(&postData,1024);
ZeroMemory(&postData2,1024);
WinHttpAddRequestHeaders(hRequest,L"Content-Type: multipart/form-data; boundary=----OiRBxC0fjdSEpqhd",-1L,WINHTTP_ADDREQ_FLAG_ADD);
wsprintfA(postData,"%s","----OiRBxC0fjdSEpqhd\r\nContent-Disposition: form-data; name=\"file\"; filename=\"blog.jpg\"\r\nContent-Type: image/jpeg\r\n\r\n");
wsprintfA(postData2,"%s","\r\n----OiRBxC0fjdSEpqhd\r\nContent-Disposition: form-data; name=\"submit\"\r\n\r\nSubmit\r\n----OiRBxC0fjdSEpqhd--\r\n");
bResults = WinHttpSendRequest( hRequest,
WINHTTP_NO_ADDITIONAL_HEADERS,
0, WINHTTP_NO_REQUEST_DATA, 0,
lstrlenA(postData)+lstrlenA(postData2)+lSize, NULL);
if (bResults)
{
bResults=WinHttpWriteData(hRequest,LPCVOID)postData,lstrlenA(postData),NULL);
bResults = WinHttpWriteData(hRequest, buffer, lSize, &dwBytesWritten);
bResults=WinHttpWriteData(hRequest,(LPCVOID)postData2,lstrlenA(postData2),NULL);
}
WinHttpWriteData: POST data - postData, postData2 must be 8 bit encoding.