截图

来源：互联网发布：零基础怎么学python 编辑：程序博客网时间：2024/04/27 07:57

//此函数为截图函数:
bool myGetScreenAndSave(CRect rc, CString lpFileName)
{
HWND hwnd = ::GetDesktopWindow();
HDC hsrc = ::GetDC(hwnd);
HDC hmemdc = ::CreateCompatibleDC(hsrc);
rc.NormalizeRect();
SIZE sz;
sz.cx=rc.right-rc.left;
sz.cy=rc.bottom-rc.top;
HBITMAP hbmp = ::CreateCompatibleBitmap(hsrc,sz.cx,sz.cy);
HGDIOBJ holdbmp = ::SelectObject(hmemdc,hbmp);
::BitBlt(hmemdc,0,0,sz.cx,sz.cx,hsrc,rc.left,rc.top,SRCCOPY);
::SelectObject(hmemdc,holdbmp);
::DeleteObject(hmemdc);
::ReleaseDC(hwnd,hsrc);

HDC hDC;
//设备描述表
  int iBits;
//当前显示分辨率下每个像素所占字节数
WORD            wBitCount;
//位图中每个像素所占字节数
DWORD           dwPaletteSize=0,
//定义调色板大小，位图中像素字节大小，位图文件大小，写入文件字节数
dwBmBitsSize,
dwDIBSize, dwWritten;
BITMAP          Bitmap;
BITMAPFILEHEADER   bmfHdr;
//位图属性结构
BITMAPINFOHEADER   bi;
  //位图文件头结构
LPBITMAPINFOHEADER lpbi;
//位图信息头结构
HANDLE          fh, hDib, hPal,hOldPal=NULL;
//指向位图信息头结构,定义文件，分配内存句柄，调色板句柄
//计算位图文件每个像素所占字节数
hDC = CreateDC(_T("DISPLAY"),NULL,NULL,NULL);
iBits = GetDeviceCaps(hDC, BITSPIXEL) *
GetDeviceCaps(hDC, PLANES);
DeleteDC(hDC);
if (iBits <= 1)
wBitCount = 1;
else
if (iBits <= 4)
wBitCount = 4;
else
if (iBits <= 8)
wBitCount = 8;
else
{
if (iBits <= 24)
wBitCount = 24;
else
wBitCount = 32;//原来没有，应有
}

   //计算调色板大小
   if (wBitCount <= 8)
   dwPaletteSize = (1 << wBitCount) *sizeof(RGBQUAD);

   //设置位图信息头结构
   GetObject(hbmp, sizeof(BITMAP), (LPSTR)&Bitmap);
   bi.biSize            = sizeof(BITMAPINFOHEADER);
   bi.biWidth           = Bitmap.bmWidth;
   bi.biHeight          = Bitmap.bmHeight;
   bi.biPlanes          = 1;
   bi.biBitCount         = wBitCount;
   bi.biCompression      = BI_RGB;
   bi.biSizeImage        = 0;
   bi.biXPelsPerMeter     = 0;
   bi.biYPelsPerMeter     = 0;
   bi.biClrUsed         = 0;
   bi.biClrImportant      = 0;

   dwBmBitsSize = ((Bitmap.bmWidth*wBitCount+31)/32)*4*Bitmap.bmHeight;


   //为位图内容分配内存
   hDib = GlobalAlloc(GHND,dwBmBitsSize+dwPaletteSize+sizeof(BITMAPINFOHEADER));

   if(hDib==NULL)
   AfxMessageBox(_T("null"));
   lpbi = (LPBITMAPINFOHEADER)GlobalLock(hDib);
   *lpbi = bi;

   // 处理调色板
   hPal = GetStockObject(DEFAULT_PALETTE);
   if (hPal)
   {
   hDC = ::GetDC(NULL);
   hOldPal = SelectPalette(hDC, (HPALETTE)hPal, FALSE);
       RealizePalette(hDC);
   }

   // 获取该调色板下新的像素值
   GetDIBits(hDC, hbmp, 0, (UINT) Bitmap.bmHeight,
   (LPSTR)lpbi + sizeof(BITMAPINFOHEADER)+dwPaletteSize,
   (LPBITMAPINFO)lpbi, DIB_RGB_COLORS);

   //恢复调色板
   if (hOldPal)
   {
   SelectPalette(hDC, (HPALETTE)hOldPal, TRUE);
   RealizePalette(hDC);
   ::ReleaseDC(NULL, hDC);
   }

   //创建位图文件
   fh = CreateFile(lpFileName, GENERIC_WRITE,
   0, NULL, CREATE_ALWAYS,
   FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, NULL);

//   if (fh == INVALID_HANDLE_value)
// return FALSE;

   // 设置位图文件头
   bmfHdr.bfType = 0x4D42; // "BM"
   dwDIBSize    = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) +
   dwPaletteSize + dwBmBitsSize;
   bmfHdr.bfSize = dwDIBSize;
   bmfHdr.bfReserved1 = 0;
   bmfHdr.bfReserved2 = 0;
   bmfHdr.bfOffBits = (DWORD)sizeof(BITMAPFILEHEADER)
   + (DWORD)sizeof(BITMAPINFOHEADER)
   + dwPaletteSize;
   // 写入位图文件头
   WriteFile(fh, (LPSTR)&bmfHdr, sizeof(BITMAPFILEHEADER), &dwWritten, NULL);
   // 写入位图文件其余内容
   WriteFile(fh, (LPSTR)lpbi, dwDIBSize,
   &dwWritten, NULL);
   //消除内存分配
   GlobalUnlock(hDib);
   GlobalFree(hDib);
   CloseHandle(fh);
   return TRUE;
}

调用:
CRect rc;
rc.bottom=800;
rc.left=0;
rc.right=1280;
rc.top=0;

CString str= _T("bitmap002.bmp");

myGetScreenAndSave(rc,str);//即可保存为"bitmap002.bmp"文件