Python Library Reference,版本3.6.5,第16.16段ctypes - Python的外部函数库,在函数原型部分中给出了演示输出参数的示例:
win32 GetWindowRect函数:
WINUSERAPI BOOL WINAPI GetWindowRect(HWND hWnd, LPCRECT lprect);
ctypes包装器:
from ctypes import POINTER, WINFUNCTYPE, windll, WinError
from ctypes.wintypes import BOOL, HWND, RECT
prototype = WINFUNCTYPE(BOOL, HWND, POINTER(RECT))
paramflags = (1, 'hwnd'), (2, 'lprect')
GetWindowRect = prototype(('GetWindowRect', windll.user32), paramflags)
现在,我如何实际使用GetWindowRect?
试
from ctypes import byref, cast
r = RECT()
h = cast(65552, HWND) # _65552_ is the return value of _GetDesktopWindow_ on my system
result = GetWindowRect([h, byref(r)])
返回ctypes.ArgumentError: argument 1: <class 'TypeError'>: wrong type
。
[Python]: ctypes - A foreign function library for Python没有提供完整的例子。
code.朋友:
#!/usr/bin/env python3
import sys
import ctypes
from ctypes import wintypes
def errcheck(result, func, args):
if not result:
raise ctypes.WinError()
rc = args[1]
return rc.left, rc.top, rc.bottom, rc.right
def test_get_window_rect(desktop_wnd_handle):
print("\n{:s}\n".format(test_get_window_rect.__name__))
prototype = ctypes.WINFUNCTYPE(wintypes.BOOL, wintypes.HWND, ctypes.POINTER(wintypes.RECT))
paramflags = (1, "hwnd"), (2, "lprect")
GetWindowRect = prototype(("GetWindowRect", ctypes.windll.user32), paramflags)
print("Without errcheck:\n")
result = GetWindowRect(ctypes.windll.user32.GetDesktopWindow())
print("Left: {:d}, Top: {:}, Right: {:d}, Bottom: {:}".format(result.left, result.top, result.right, result.bottom))
result = GetWindowRect(0)
print("Left: {:d}, Top: {:}, Right: {:d}, Bottom: {:}".format(result.left, result.top, result.right, result.bottom))
GetWindowRect.errcheck = errcheck
print("\nWith errcheck:\n")
result = GetWindowRect(desktop_wnd_handle)
print("Left: {:d}, Top: {:}, Right: {:d}, Bottom: {:}".format(*result))
result = GetWindowRect(0)
print("Left: {:d}, Top: {:}, Right: {:d}, Bottom: {:}".format(*result))
def test_get_window_rect_old_style(desktop_wnd_handle):
print("\n{:s}\n".format(test_get_window_rect_old_style.__name__))
user32_dll = ctypes.WinDLL("user32")
get_windows_rect_func = user32_dll.GetWindowRect
get_windows_rect_func.argtypes = [wintypes.HWND, ctypes.POINTER(wintypes.RECT)]
get_windows_rect_func.restype = wintypes.BOOL
rect = wintypes.RECT()
result = get_windows_rect_func(desktop_wnd_handle, ctypes.byref(rect))
print("Result: {:d}\nLeft: {:d}, Top: {:}, Right: {:d}, Bottom: {:}".format(result, rect.left, rect.top, rect.right, rect.bottom))
rect = wintypes.RECT()
result = get_windows_rect_func(0, ctypes.byref(rect))
print("Result: {:d}\nLeft: {:d}, Top: {:}, Right: {:d}, Bottom: {:}".format(result, rect.left, rect.top, rect.right, rect.bottom))
def main():
hwnd = ctypes.windll.user32.GetDesktopWindow()
test_get_window_rect_old_style(hwnd)
test_get_window_rect(hwnd)
if __name__ == "__main__":
print("Python {:s} on {:s}\n".format(sys.version, sys.platform))
main()
笔记:
输出:
(py35x64_test) e:\Work\Dev\StackOverflow\q050669907>"e:\Work\Dev\VEnvs\py35x64_test\Scripts\python.exe" code.py Python 3.5.4 (v3.5.4:3f56838, Aug 8 2017, 02:17:05) [MSC v.1900 64 bit (AMD64)] on win32 test_get_window_rect_old_style Result: 1 Left: 0, Top: 0, Right: 1920, Bottom: 1080 Result: 0 Left: 0, Top: 0, Right: 0, Bottom: 0 test_get_window_rect Without errcheck: Left: 0, Top: 0, Right: 1920, Bottom: 1080 Left: 0, Top: 0, Right: 0, Bottom: 0 With errcheck: Left: 0, Top: 0, Right: 1080, Bottom: 1920 Traceback (most recent call last): File "code.py", line 58, in <module> main() File "code.py", line 53, in main test_get_window_rect(hwnd) File "code.py", line 30, in test_get_window_rect result = GetWindowRect(0) File "code.py", line 9, in errcheck raise ctypes.WinError() OSError: [WinError 1400] Invalid window handle.