DIRECTX 九 SDK里面有没有屏幕抓图的例子

DIRECTX 9 SDK里面有没有屏幕抓图的例子？
DIRECTX 9 SDK里面有没有屏幕抓图的例子？如果没有哪里可以找到？
------解决方案--------------------
1,Getbackbuffer(...)
2,CreateSurface (d3dpool_system)
3,StretchRect backbuffer -> ysytembuffer
4,D3DXSaveSurfaceToFile
------解决方案--------------------
void CrD3DWndCL::RenderToFileM( const CString &fileName, CString *pOrgFileName, BOOL bClear, D3DXIMAGE_FILEFORMAT format )
{
   IDirect3DSurface9 *pOldSurface = NULL;
   IDirect3DSurface9 *pSurfOldDepthStencil = NULL;
   IDirect3DSurface9 *pNewSurface = NULL;
   IDirect3DDevice9  *pd3dDevice = graphicsM.GetDeviceCOM();
   IDirect3DTexture9 *pTex  = NULL;
   HRESULT  hr;   
   ASSERT( pd3dDevice != NULL );

   if( pOrgFileName == NULL )
   {
      CRect wndRc;
      GetClientRect( &wndRc );
      hr = pd3dDevice->CreateTexture( wndRc.Width(), wndRc.Height(), 1,
                                               D3DUSAGE_RENDERTARGET,
                                               D3DFMT_A8R8G8B8,
                                               D3DPOOL_DEFAULT, &pTex, NULL );
      if( FAILED( hr ) )
      {
         TRACE( "创建纹理失败！\n" );
         return;
      }
   }
   else
   {
      CString orgFile( *pOrgFileName );
      hr = D3DXCreateTextureFromFileEx( pd3dDevice, orgFile, D3DX_DEFAULT, D3DX_DEFAULT, D3DX_FROM_FILE,
         D3DUSAGE_RENDERTARGET,D3DFMT_UNKNOWN, D3DPOOL_DEFAULT,D3DX_FILTER_LINEAR, D3DX_FILTER_LINEAR, 0,0,0, &pTex);
      if( FAILED( hr ) )
      {
         TRACE( "加载纹理图片(%s)失败！\n", orgFile );
         return;
      }
   }
   ASSERT( pTex != NULL );
   pTex->GetSurfaceLevel( 0, &pNewSurface );
   ASSERT( pNewSurface != NULL );

   setLightM( );