[Winhttp]_[C/C++]_[使用win32 SDK的Windows HTTP Services(WinHTTP)通过代理下载网页]

场景:

1.使用win32 SDK的话编译出来的程序比第3方库更小更容易控制。

2.缺点就是不能跨平台，在linux上边又需要重新写一套实现。

3.优点就是可以对win32 SDK使用更熟悉。

程序没怎么整理,有时间再弄。

// test_http.cpp : 定义控制台应用程序的入口点。
//

#include <stdio.h>

#include "windows.h"
#include "Winhttp.h"

void WinDownload()
{
  DWORD dwSize = 0;
  DWORD dwDownloaded = 0;
  LPSTR pszOutBuffer;
  BOOL  bResults = FALSE;
  HINTERNET  hSession = NULL, 
             hConnect = NULL,
             hRequest = NULL;

  // Use WinHttpOpen to obtain a session handle.
  hSession = WinHttpOpen( L"WinHTTP Example/1.0",  
                          WINHTTP_ACCESS_TYPE_NAMED_PROXY,
                          L"192.168.0.1:808", 
                          L"192.168.0.1:808", 0 );

  //hSession = WinHttpOpen( L"WinHTTP Example/1.0",  
  //                        WINHTTP_ACCESS_TYPE_NO_PROXY,
  //                        WINHTTP_NO_PROXY_NAME, 
  //                        WINHTTP_NO_PROXY_BYPASS, 0 );
  
  // Specify an HTTP server.
  if( hSession )
    hConnect = WinHttpConnect( hSession, L"www.w3school.com.cn",
                               INTERNET_DEFAULT_HTTP_PORT, 0 );
  // Create an HTTP request handle.
  if( hConnect )
    hRequest = WinHttpOpenRequest( hConnect, L"GET", L"/example/xmle/note.xml",
                                   NULL, WINHTTP_NO_REFERER, 
                                   WINHTTP_DEFAULT_ACCEPT_TYPES, 
                                   WINHTTP_FLAG_REFRESH );

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

  // End the request.
  if( bResults )
    bResults = WinHttpReceiveResponse( hRequest, NULL );
  
  // Keep checking for data until there is nothing left.
  if( bResults )
  {
    do 
    {
      // Check for available data.
      dwSize = 0;
      if( !WinHttpQueryDataAvailable( hRequest, &dwSize ) )
        printf( "Error %u in WinHttpQueryDataAvailable.\n",
                GetLastError( ) );

      // Allocate space for the buffer.
	  
      pszOutBuffer = new char[dwSize+1];
      if( !pszOutBuffer )
      {
        printf( "Out of memory\n" );
        dwSize=0;
      }
      else
      {
        // Read the data.
        ZeroMemory( pszOutBuffer, dwSize+1 );

        if( !WinHttpReadData( hRequest, (LPVOID)pszOutBuffer, 
                              dwSize, &dwDownloaded ) )
          printf( "Error %u in WinHttpReadData.\n", GetLastError( ) );
        else
          printf( "%s", pszOutBuffer );

        // Free the memory allocated to the buffer.
        delete [] pszOutBuffer;
      }
    } while( dwSize > 0 );
  }

  // 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 );
	
}

int main(int argc, char* argv[])
{
	WinDownload();
	return 0;
}