[python-win32] How to take a snapshot of a specific control?

[Ray Schumacher]

Thanks for the reply,

At 08:06 PM 12/10/2006, Mark Hammond wrote:
 > I'm trying to do a fast desktop capture myself, and having DC/pyDC
 > confusion.

I'm not sure exactly what this means, but I'm guessing you are having
trouble with the pythonwin/win32ui GetSafeHdc objects, versus those 
used by win32gui.

I'm generally confused by DC/pyDC, PyCDC, selecting and blitting..

The goal is to get a 640x480 RGB image data string from the screen 
window that I can pass to pyMedia.

I've tried various permutations of the below lines, but I realize 
that I really don't get the Windows DC/BMP/blit concepts: the order 
that windows-handles-DCs-blits-selects-BMPs need to be created.

These lines all execute:
dtwnd = win32gui.GetDesktopWindow()
hdcSrc = win32gui.GetWindowDC(dtwnd)
hdcDestH = win32ui.CreateDCFromHandle(dtwnd)
hdcDest = win32gui.CreateCompatibleDC(hdcSrc)
hBitmap = win32gui.CreateCompatibleBitmap(hdcSrc, 1024, 768)
win32gui.SelectObject(hdcDest, hBitmap)
destHDC = hdcDestH.GetSafeHdc()

but I start having trouble with
   hdcDestH.BitBlt((0, 0), (1024, 768), hdcSrc, (0, 0), 0x00CC0020)
   TypeError: The 'O' param must be a PyCDC object
and on from there.
I can't say that I need anything from win32ui, since I don't know 
what I need at all!

Thank you,
Ray