After hours of googling I managed to "write" this:
import win32gui
from ctypes import windll
hwnd = win32gui.FindWindow(None, 'Steam')
hdc = win32gui.GetDC(hwnd)
hdcMem = win32gui.CreateCompatibleDC(hdc)
hbitmap = win32ui.CreateBitmap()
hbitmap = win32gui.CreateCompatibleBitmap(hdcMem, 500, 500)
win32gui.SelectObject(hdcMem, hbitmap)
windll.user32.PrintWindow(hwnd, hdcMem, 0)
Is this a correct way to do this and how would I save an image?
After lots of searching and trying various different methods, the following worked for me.
import win32gui
import win32ui
from ctypes import windll
from PIL import Image
hwnd = win32gui.FindWindow(None, 'Calculator')
# Uncomment the following line if you use a high DPI display or >100% scaling size
# windll.user32.SetProcessDPIAware()
# Change the line below depending on whether you want the whole window
# or just the client area.
#left, top, right, bot = win32gui.GetClientRect(hwnd)
left, top, right, bot = win32gui.GetWindowRect(hwnd)
w = right - left
h = bot - top
hwndDC = win32gui.GetWindowDC(hwnd)
mfcDC = win32ui.CreateDCFromHandle(hwndDC)
saveDC = mfcDC.CreateCompatibleDC()
saveBitMap = win32ui.CreateBitmap()
saveBitMap.CreateCompatibleBitmap(mfcDC, w, h)
saveDC.SelectObject(saveBitMap)
# Change the line below depending on whether you want the whole window
# or just the client area.
#result = windll.user32.PrintWindow(hwnd, saveDC.GetSafeHdc(), 1)
result = windll.user32.PrintWindow(hwnd, saveDC.GetSafeHdc(), 0)
print result
bmpinfo = saveBitMap.GetInfo()
bmpstr = saveBitMap.GetBitmapBits(True)
im = Image.frombuffer(
'RGB',
(bmpinfo['bmWidth'], bmpinfo['bmHeight']),
bmpstr, 'raw', 'BGRX', 0, 1)
win32gui.DeleteObject(saveBitMap.GetHandle())
saveDC.DeleteDC()
mfcDC.DeleteDC()
win32gui.ReleaseDC(hwnd, hwndDC)
if result == 1:
#PrintWindow Succeeded
im.save("test.png")