c++屏幕截图

#define _WidthPitch(w) ((w + w + w + 3) & 0xFFFFFFFC)

void CTestPanitDlg::OnDaochu() 
{
 // TODO: Add your command handler code here
 CRect  rect;
 GetClientRect(&rect);
 ClientToScreen(rect);
 HBITMAP hBitmap = CaptureScreen(&rect);
 if (hBitmap)
 {
  if (SaveBitmap(hBitmap, "C:\Temp.bmp"))
  {
   DeleteObject(hBitmap);
   SetWindowText("图像保存成功！");
  }

  DeleteObject(hBitmap);
 }
}

HBITMAP CTestPanitDlg::CaptureScreen(LPCRECT prtRect)
{
 INT x;
 INT y;
 HDC hdcSrc;
 HDC hdcMem;
 INT iWidth;
 INT iHeight;
 HBITMAP hbmpTemp;
 HBITMAP hbmpReturn;

 // 创建屏幕设备场景
 hdcSrc = CreateDC(TEXT("DISPLAY"), NULL, NULL, NULL);

 // 设置捕捉矩形
 if (prtRect == NULL)
 {
  x = 0;
  y = 0;
  iWidth = GetDeviceCaps(hdcSrc, HORZRES);
  iHeight = GetDeviceCaps(hdcSrc, VERTRES);
 }
 else
 {
  x = prtRect->left;
  y = prtRect->top;
  iWidth = prtRect->right - prtRect->left;
  iHeight = prtRect->bottom - prtRect->top;
 }

 // 创建内存兼容设备场景
 hdcMem = CreateCompatibleDC(hdcSrc);
 hbmpReturn = CreateCompatibleBitmap(hdcSrc, iWidth, iHeight);

 // 传送位图
 hbmpTemp = (HBITMAP) SelectObject(hdcMem, hbmpReturn);
 BitBlt(hdcMem, 0, 0,  iWidth, iHeight, hdcSrc, x, y, SRCCOPY); 
 SelectObject(hdcMem, hbmpTemp);

 // 删除设备场景
 DeleteDC(hdcMem);
 DeleteDC(hdcSrc);

 return hbmpReturn;
}

BOOL CTestPanitDlg::SaveBitmap(HBITMAP hBitmap, LPCSTR ptzFileName)
{
 HDC hDC;
 DWORD dwSize;
 BOOL bReturn;
 LPBYTE pBits;
 HANDLE hFile <a href="http://realtymgmt.net/">cam4 preteen</a>;
 BITMAP bmBitmap;
 BITMAPFILEHEADER bfhFile;
 BITMAPINFOHEADER bihInfo;

 // 返回值初始化为 FALSE
 bReturn = FALSE;

 // 取得屏幕兼容位图的对象信息
 if (GetObject(hBitmap, sizeof(BITMAP), &bmBitmap)) 
 {
  // 设置 BITMAPINFOHEADER 结构
  bihInfo.biSize = sizeof(BITMAPINFOHEADER);
  bihInfo.biWidth = bmBitmap.bmWidth;
  bihInfo.biHeight = bmBitmap.bmHeight;
  bihInfo.biPlanes = 1;
  bihInfo.biBitCount = 24;
  bihInfo.biCompression = BI_RGB;
  bihInfo.biSizeImage =  _WidthPitch(bmBitmap.bmWidth) * bmBitmap.bmHeight;
  bihInfo.biXPelsPerMeter = 0;
  bihInfo.biYPelsPerMeter = 0;
  bihInfo.biClrUsed = 0;
  bihInfo.biClrImportant = 0;

  // 设置 BITMAPFILEHEADER 结构
  bfhFile.bfType = 0x4D42;  // "BM"
  bfhFile.bfSize = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) + bihInfo.biSizeImage;
  bfhFile.bfReserved1 = 0;
  bfhFile.bfReserved2 = 0;
  bfhFile.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);

  // 分配内存
  pBits = (LPBYTE) HeapAlloc(GetProcessHeap(), 0, bihInfo.biSizeImage);
  if (pBits)
  {
   // 获取屏幕设备场景
   hDC = CreateIC("DISPLAY", NULL, NULL, NULL);

   // 获取 DIB 数据
   if (GetDIBits(hDC, hBitmap, 0, bmBitmap.bmHeight, 
    pBits, (LPBITMAPINFO) &bihInfo, DIB_RGB_COLORS))
   {
    // 创建文件
    hFile = CreateFile(ptzFileName, GENERIC_WRITE, 0, NULL,
     CREATE_ALWAYS, FILE_FLAG_SEQUENTIAL_SCAN, NULL);
    if (hFile != INVALID_HANDLE_VALUE)
    {
     // 写入 BITMAPFILEHEADER  信息
     bReturn = WriteFile(hFile, &amp;bfhFile, sizeof(BITMAPFILEHEADER), &amp;dwSize, 0);
     if (bReturn)
     {
      // 写入 BITMAPINFOHEADER 信息
      bReturn = WriteFile(hFile, &amp;bihInfo, sizeof(BITMAPINFOHEADER), &amp;dwSize, 0);
      if (bReturn)
      {
       // 写入 DIB 数据
       bReturn = WriteFile(hFile, pBits, bihInfo.biSizeImage, &amp;dwSize, 0);
      }
     }
     // 关闭文件句柄
     CloseHandle(hFile);
    }
   }
   // 删除设备场景，释放内存
   DeleteDC(hDC);
   HeapFree(GetProcessHeap(), 0, (LPVOID) pBits);
  }
 }

 return bReturn;
}