-- 发布时间：2/5/2006 10:35:00 AM
-- [B]一个屏幕捕捉的例子[/B]
自己做的一个屏幕捕捉的软件，可以捕捉全屏、窗口和子窗口，可以保存到文件中。程序的主要的代码如下：
根据位图的句柄将位图写入文件：
void CPage1::WriteBmpToFile(HBITMAP hBitmap)
{
HDC hDC =::CreateDC("DISPLAY",NULL,NULL,NULL);
int iBits = ::GetDeviceCaps(hDC, BITSPIXEL) * ::GetDeviceCaps(hDC, PLANES);//当前分辨率下每个像素所占字节数
::DeleteDC(hDC);
WORD wBitCount; //位图中每个像素所占字节数
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 = iBits;
DWORD dwPaletteSize=0; //调色板大小， 位图中像素字节大小
if (wBitCount <= 8)
dwPaletteSize = (1 << wBitCount) * sizeof(RGBQUAD);
BITMAP bm; //位图属性结构
::GetObject(hBitmap, sizeof(bm), (LPSTR)&bm);
BITMAPINFOHEADER bi; //位图信息头结构
bi.biSize = sizeof(BITMAPINFOHEADER);
bi.biWidth = bm.bmWidth;
bi.biHeight = bm.bmHeight;
bi.biPlanes = 1;
bi.biBitCount = wBitCount;
bi.biCompression = BI_RGB; //BI_RGB表示位图没有压缩
bi.biSizeImage = 0;
bi.biXPelsPerMeter = 0;
bi.biYPelsPerMeter = 0;
bi.biClrUsed = 0;
bi.biClrImportant = 0;
DWORD dwBmBitsSize = ((bm.bmWidth * wBitCount+31)/32) * 4 * bm.bmHeight;
HANDLE hDib = ::GlobalAlloc(GHND,dwBmBitsSize + dwPaletteSize + sizeof(BITMAPINFOHEADER)); //为位图内容分配内存
LPBITMAPINFOHEADER lpbi = (LPBITMAPINFOHEADER)GlobalLock(hDib);
*lpbi = bi;
HANDLE hPal = ::GetStockObject(DEFAULT_PALETTE); // 处理调色板
HANDLE hOldPal=NULL;
if (hPal)
{
hDC = ::GetDC(NULL);
hOldPal = SelectPalette(hDC,(HPALETTE)hPal, FALSE);
RealizePalette(hDC);
}
::GetDIBits(hDC, hBitmap, 0, (UINT) bm.bmHeight,(LPSTR)lpbi + sizeof(BITMAPINFOHEADER)+dwPaletteSize,(BITMAPINFO*)lpbi,DIB_RGB_COLORS);// 获取该调色板下新的像素值
if (hOldPal)//恢复调色板
{
SelectPalette(hDC, (HPALETTE)hOldPal, TRUE);
RealizePalette(hDC);
::ReleaseDC(NULL, hDC);
}
BITMAPFILEHEADER bmfHdr; //位图文件头结构
bmfHdr.bfType = 0x4D42; // "BM" // 设置位图文件头
DWORD 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;
HANDLE hFile = CreateFile(m_strFilePath, GENERIC_WRITE, 0, NULL, CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, NULL);//创建位图文件
DWORD dwWritten;
WriteFile(hFile, (LPSTR)&bmfHdr, sizeof(BITMAPFILEHEADER), &dwWritten, NULL); // 写入位图文件头
WriteFile(hFile, (LPSTR)lpbi, dwDIBSize, &dwWritten, NULL);// 写入位图文件其余内容
GlobalUnlock(hDib); //清除
GlobalFree(hDib);
CloseHandle(hFile);
}
二、将位图复制到剪贴板上：
void CPage1::CopyBmpToClipBoard(HBITMAP hBitmap)
{
OpenClipboard() ; //打开剪贴板，并将位图拷到剪贴板上
EmptyClipboard();
SetClipboardData(CF_BITMAP, hBitmap);
CloseClipboard(); //关闭剪贴板
}
程序运行界面：
