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Python3 ctype Simple CreateWindowEx Example

I searched Google for some time, but could not find a simple example of ctypes python3 and the Win32 API to create and display a window. Please provide me with a good link or code here.

Thanks in advance!

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2 answers

This is easiest to do with the win32gui module and its friends, win32api and win32con. There is no need to write your own ctypes wrappers in the Windows API. The simplest Petzold style app looks something like this:

import win32api, win32con, win32gui

class MyWindow:

    def __init__(self):
        win32gui.InitCommonControls()
        self.hinst = win32api.GetModuleHandle(None)
        className = 'MyWndClass'
        message_map = {
            win32con.WM_DESTROY: self.OnDestroy,
        }
        wc = win32gui.WNDCLASS()
        wc.style = win32con.CS_HREDRAW | win32con.CS_VREDRAW
        wc.lpfnWndProc = message_map
        wc.lpszClassName = className
        win32gui.RegisterClass(wc)
        style = win32con.WS_OVERLAPPEDWINDOW
        self.hwnd = win32gui.CreateWindow(
            className,
            'My win32api app',
            style,
            win32con.CW_USEDEFAULT,
            win32con.CW_USEDEFAULT,
            300,
            300,
            0,
            0,
            self.hinst,
            None
        )
        win32gui.UpdateWindow(self.hwnd)
        win32gui.ShowWindow(self.hwnd, win32con.SW_SHOW)

    def OnDestroy(self, hwnd, message, wparam, lparam):
        win32gui.PostQuitMessage(0)
        return True

w = MyWindow()
win32gui.PumpMessages()
+6
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, , vanilla python 3.4.0:
( , PyWin32)
http://code.activestate.com/recipes/208699-calling-windows-api-using-ctypes-and-win32con/

import sys
from ctypes import *

kernel32 = windll.kernel32
user32 = windll.user32
gdi32 = windll.gdi32

NULL = 0
CW_USEDEFAULT = -2147483648
IDI_APPLICATION = 32512
WS_OVERLAPPEDWINDOW = 13565952

CS_HREDRAW = 2
CS_VREDRAW = 1

IDC_ARROW = 32512
WHITE_BRUSH = 0

SW_SHOWNORMAL = 1

WNDPROC = WINFUNCTYPE(c_long, c_int, c_uint, c_int, c_int)

class WNDCLASS(Structure):
    _fields_ = [('style', c_uint),
                ('lpfnWndProc', WNDPROC),
                ('cbClsExtra', c_int),
                ('cbWndExtra', c_int),
                ('hInstance', c_int),
                ('hIcon', c_int),
                ('hCursor', c_int),
                ('hbrBackground', c_int),
                ('lpszMenuName', c_char_p),
                ('lpszClassName', c_char_p)]

class RECT(Structure):
    _fields_ = [('left', c_long),
                ('top', c_long),
                ('right', c_long),
                ('bottom', c_long)]

class PAINTSTRUCT(Structure):
    _fields_ = [('hdc', c_int),
                ('fErase', c_int),
                ('rcPaint', RECT),
                ('fRestore', c_int),
                ('fIncUpdate', c_int),
                ('rgbReserved', c_char * 32)]

class POINT(Structure):
    _fields_ = [('x', c_long),
                ('y', c_long)]

class MSG(Structure):
    _fields_ = [('hwnd', c_int),
                ('message', c_uint),
                ('wParam', c_int),
                ('lParam', c_int),
                ('time', c_int),
                ('pt', POINT)]

def ErrorIfZero(handle):
    if handle == 0:
        raise WinError
    else:
        return handle

def MainWin():
    global NULL
    CreateWindowEx          = user32.CreateWindowExA
    CreateWindowEx.argtypes = [c_int, c_char_p, c_char_p, c_int, c_int, c_int, c_int, c_int, c_int, c_int, c_int, c_int]
    CreateWindowEx.restype  = ErrorIfZero

    # Define Window Class
    wndclass = WNDCLASS()
    wndclass.style          = CS_HREDRAW | CS_VREDRAW
    wndclass.lpfnWndProc    = WNDPROC(WndProc)
    wndclass.cbClsExtra = wndclass.cbWndExtra = 0
    wndclass.hInstance      = kernel32.GetModuleHandleA(c_int(NULL))
    wndclass.hIcon          = user32.LoadIconA(c_int(NULL), c_int(IDI_APPLICATION))
    wndclass.hCursor        = user32.LoadCursorA(c_int(NULL), c_int(IDC_ARROW))
    wndclass.hbrBackground  = gdi32.GetStockObject(c_int(WHITE_BRUSH))
    wndclass.lpszMenuName   = None
    wndclass.lpszClassName  = b"MainWin"
    # Register Window Class
    if not user32.RegisterClassA(byref(wndclass)):
        raise WinError()
    # Create Window
    hwnd = CreateWindowEx(0,
                          wndclass.lpszClassName,
                          b"Python Window",
                          WS_OVERLAPPEDWINDOW,
                          CW_USEDEFAULT,
                          CW_USEDEFAULT,
                          CW_USEDEFAULT,
                          CW_USEDEFAULT,
                          NULL,
                          NULL,
                          wndclass.hInstance,
                          NULL)
    # Show Window
    user32.ShowWindow(c_int(hwnd), c_int(SW_SHOWNORMAL))
    user32.UpdateWindow(c_int(hwnd))
    # Pump Messages
    msg = MSG()
    pMsg = pointer(msg)
    NULL = c_int(NULL)

    while user32.GetMessageA( pMsg, NULL, 0, 0) != 0:
        user32.TranslateMessage(pMsg)
        user32.DispatchMessageA(pMsg)

    return msg.wParam

WM_PAINT = 15
WM_DESTROY = 2

DT_SINGLELINE = 32
DT_CENTER = 1
DT_VCENTER = 4
def WndProc(hwnd, message, wParam, lParam):
    ps = PAINTSTRUCT()
    rect = RECT()

    if message == WM_PAINT:
        hdc = user32.BeginPaint(c_int(hwnd), byref(ps))
        user32.GetClientRect(c_int(hwnd), byref(rect))
        user32.DrawTextA(c_int(hdc),
                         b"Python Powered Windows" ,
                         c_int(-1), byref(rect), 
                         DT_SINGLELINE|DT_CENTER|DT_VCENTER)
        user32.EndPaint(c_int(hwnd), byref(ps))
        return 0
    elif message == WM_DESTROY:
        user32.PostQuitMessage(0)
        return 0

    return user32.DefWindowProcA(c_int(hwnd), c_int(message), c_int(wParam), c_int(lParam))

if __name__=='__main__':
    sys.exit(MainWin())


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