如何在Windows应用程序中截屏？

Question

如何使用Win32截屏当前屏幕？

Answer 1

// get the device context of the screen

HDC hScreenDC = CreateDC("DISPLAY", NULL, NULL, NULL);     

// and a device context to put it in

HDC hMemoryDC = CreateCompatibleDC(hScreenDC);

int width = GetDeviceCaps(hScreenDC, HORZRES);

int height = GetDeviceCaps(hScreenDC, VERTRES);

// maybe worth checking these are positive values

HBITMAP hBitmap = CreateCompatibleBitmap(hScreenDC, width, height);

// get a new bitmap

HBITMAP hOldBitmap = (HBITMAP) SelectObject(hMemoryDC, hBitmap);

BitBlt(hMemoryDC, 0, 0, width, height, hScreenDC, 0, 0, SRCCOPY);

hBitmap = (HBITMAP) SelectObject(hMemoryDC, hOldBitmap);

// clean up

DeleteDC(hMemoryDC);

DeleteDC(hScreenDC);

// now your image is held in hBitmap. You can save it or do whatever with it

Answer 2

void GetScreenShot(void)

{

    int x1, y1, x2, y2, w, h;

    // get screen dimensions

    x1  = GetSystemMetrics(SM_XVIRTUALSCREEN);

    y1  = GetSystemMetrics(SM_YVIRTUALSCREEN);

    x2  = GetSystemMetrics(SM_CXVIRTUALSCREEN);

    y2  = GetSystemMetrics(SM_CYVIRTUALSCREEN);

    w   = x2 - x1;

    h   = y2 - y1;

    // copy screen to bitmap

    HDC     hScreen = GetDC(NULL);

    HDC     hDC     = CreateCompatibleDC(hScreen);

    HBITMAP hBitmap = CreateCompatibleBitmap(hScreen, w, h);

    HGDIOBJ old_obj = SelectObject(hDC, hBitmap);

    BOOL    bRet    = BitBlt(hDC, 0, 0, w, h, hScreen, x1, y1, SRCCOPY);

    // save bitmap to clipboard

    OpenClipboard(NULL);

    EmptyClipboard();

    SetClipboardData(CF_BITMAP, hBitmap);

    CloseClipboard();   

    // clean up

    SelectObject(hDC, old_obj);

    DeleteDC(hDC);

    ReleaseDC(NULL, hScreen);

    DeleteObject(hBitmap);

}