HBITMAP CopyScreenToBitmap(LPRECT lpRect) //lpRect 代表選定區域
{
HDC hScrDC, hMemDC;
// 屏幕和內存設備描述表
HBITMAP hBitmap, hOldBitmap;
// 位圖句柄
int nX, nY, nX2, nY2;
// 選定區域座標
int nWidth, nHeight;
// 位圖寬度和高度
int xScrn, yScrn;
// 屏幕分辨率
// 確保選定區域不爲空矩形
if (IsRectEmpty(lpRect))
return NULL;
//爲屏幕創建設備描述表
hScrDC = CreateDC("DISPLAY", NULL, NULL, NULL);
//爲屏幕設備描述表創建兼容的內存設備描述表
hMemDC = CreateCompatibleDC(hScrDC);
// 獲得選定區域座標
nX = lpRect->left;
nY = lpRect->top;
nX2 = lpRect->right;
nY2 = lpRect->bottom;
// 獲得屏幕分辨率
xScrn = GetDeviceCaps(hScrDC, HORZRES);
yScrn = GetDeviceCaps(hScrDC, VERTRES);
//確保選定區域是可見的
if (nX <0)
nX = 0;
if (nY <0)
nY = 0;
if (nX2 > xScrn)
nX2 = xScrn;
if (nY2 > yScrn)
nY2 = yScrn;
nWidth = nX2 - nX;
nHeight = nY2 - nY;
// 創建一個與屏幕設備描述表兼容的位圖
hBitmap = CreateCompatibleBitmap
(hScrDC, nWidth, nHeight);
// 把新位圖選到內存設備描述表中
hOldBitmap = (HBITMAP)SelectObject(hMemDC, hBitmap);
// 把屏幕設備描述表拷貝到內存設備描述表中
BitBlt(hMemDC, 0, 0, nWidth, nHeight,
hScrDC, nX, nY, SRCCOPY);
//得到屏幕位圖的句柄
hBitmap = (HBITMAP)SelectObject(hMemDC, hOldBitmap);
//清除
DeleteDC(hScrDC);
DeleteDC(hMemDC);
// 返回位圖句柄
return hBitmap;
}
//得到屏幕位圖句柄以後,我們
//可以把屏幕內容粘貼到剪貼板上.
void OpClip(HBITMAP hBitmap, HWND jhWnd)
{
if(OpenClipboard(jhWnd))
//hWnd爲程序窗口句柄
//清空剪貼板
EmptyClipboard();
//把屏幕內容粘貼到剪貼板上,
//hBitmap 爲剛纔的屏幕位圖句柄
SetClipboardData(CF_BITMAP, hBitmap);
//關閉剪貼板
CloseClipboard();
}
//我們也可以把屏幕內容以位圖格式存到磁盤文件上.
//hBitmap 爲剛纔的屏幕位圖句柄
int SaveBitmapToFile(HBITMAP hBitmap , LPSTR lpFileName)
{
//lpFileName 爲位圖文件名
HDC hDC;
//設備描述表
int iBits;
//當前顯示分辨率下每個像素所佔字節數
WORD wBitCount;
//位圖中每個像素所佔字節數
//定義調色板大小, 位圖中像素字節大小 ,
//位圖文件大小 , 寫入文件字節數
DWORD dwPaletteSize=0,
dwBmBitsSize,
dwDIBSize, dwWritten;
BITMAP Bitmap;
//位圖屬性結構
BITMAPFILEHEADER bmfHdr;
//位圖文件頭結構
BITMAPINFOHEADER bi;
//位圖信息頭結構
LPBITMAPINFOHEADER lpbi;
//指向位圖信息頭結構
HANDLE fh, hDib, hPal;
HPALETTE hOldPal=NULL;
//定義文件,分配內存句柄,調色板句柄
//計算位圖文件每個像素所佔字節數
hDC = CreateDC("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;
//計算調色板大小
if (wBitCount <= 8)
dwPaletteSize = (1 <<wBitCount) *
sizeof(RGBQUAD);
//設置位圖信息頭結構
GetObject(hBitmap, 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 ;
//爲位圖內容分配內存
hDib = GlobalAlloc(GHND,dwBmBitsSize+
dwPaletteSize+sizeof(BITMAPINFOHEADER));
lpbi = (LPBITMAPINFOHEADER)GlobalLock(hDib);
*lpbi = bi;
// 處理調色板
hPal = GetStockObject(DEFAULT_PALETTE);
if (hPal)
{
hDC = GetDC(NULL);
hOldPal = (HPALETTE)SelectPalette(hDC, (HPALETTE)hPal, FALSE);
RealizePalette(hDC);
}
// 獲取該調色板下新的像素值
GetDIBits(hDC, hBitmap, 0, (UINT) Bitmap.bmHeight,
(LPSTR)lpbi + sizeof(BITMAPINFOHEADER)
+dwPaletteSize,
(tagBITMAPINFO *)
lpbi, DIB_RGB_COLORS);
//恢復調色板
if (hOldPal)
{
SelectPalette(hDC, hOldPal, TRUE);
RealizePalette(hDC);
ReleaseDC(NULL, hDC);
}
//創建位圖文件
fh = CreateFile(lpFileName, GENERIC_WRITE,
0, NULL, CREATE_ALWAYS,
FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, NULL);
if (fh == INVALID_HANDLE_VALUE)
return FALSE;
// 設置位圖文件頭
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;
// 寫入位圖文件頭
WriteFile(fh, (LPSTR)&bmfHdr, sizeof
(BITMAPFILEHEADER), &dwWritten, NULL);
// 寫入位圖文件其餘內容
WriteFile(fh, (LPSTR)lpbi, dwDIBSize,
&dwWritten, NULL);
//清除
GlobalUnlock(hDib);
GlobalFree(hDib);
CloseHandle(fh);
return 0;
}