Grab window content

Question

 

Hi all,

 

I'm trying to grab a window content so that I can later convert it into a bitmap image.

 

Is it possible? I know how to get the window handler and how to resize it with that handler but, how could I grab a picture like Print Screen currently does.

 

Thank you in advance.

Answer 1

Code Snippet

1. Get screen DC

HDC hdcScreen = GetDC(NULL);

 

2. Get Window (being captured) bounds

RECT rcWindow;

GetWindowRect(hwnd);

 

3. Allocated a DC and a bitmap:

 

HDC hdcMem = CreateCompatibleDC(hdcScreen);

HBITMAP hbmCapture = CreateCompatibleBitmap(hdcScreen, rcWindow.right - rcWindow.left, rcWindow.bottom - rcWindow.top);

HGDIOBJ hbm = SelectObject(hdcMem, hbmCapture);

 

4. Blit a block to the memory DC

 

BitBlt(hdcMem, 0, 0, rcWindow.right - rcWindow.left, rcWindow.bottom - rcWindow.top, hdcScreen, rcWindow.left, rcWindow.top, SRCCOPY);