User32_DrawText.py

import win32api
import win32con
import win32gui
# https://www.christophekeller.com/hello-world-in-python-using-win32/

def main():
    #get instance handle
    hInstance = win32api.GetModuleHandle()

    # the class name
    className = 'SimpleWin32'


    # create and initialize window class
    wndClass                = win32gui.WNDCLASS()
    wndClass.style          = win32con.CS_HREDRAW | win32con.CS_VREDRAW
    wndClass.lpfnWndProc    = wndProc
    wndClass.hInstance      = hInstance
    wndClass.hIcon          = win32gui.LoadIcon(0, win32con.IDI_APPLICATION)
    wndClass.hCursor        = win32gui.LoadCursor(0, win32con.IDC_ARROW)
    wndClass.hbrBackground  = win32gui.GetStockObject(win32con.WHITE_BRUSH)
    wndClass.lpszClassName  = className

    # register window class
    wndClassAtom = None
    try:
        wndClassAtom = win32gui.RegisterClass(wndClass)
    except:
        print(e)
        raise e

    print(wndClassAtom)
    hWindow = win32gui.CreateWindow(
        wndClassAtom,                   #it seems message dispatching only works with the atom, not the class name
        'Python Win32 Window',
        win32con.WS_OVERLAPPEDWINDOW,
        win32con.CW_USEDEFAULT,
        win32con.CW_USEDEFAULT,
        win32con.CW_USEDEFAULT,
        win32con.CW_USEDEFAULT,
        0,
        0,
        hInstance,
        None)

    # Show & update the window
    win32gui.ShowWindow(hWindow, win32con.SW_SHOWNORMAL)
    win32gui.UpdateWindow(hWindow)

    # Dispatch messages
    win32gui.PumpMessages()



def wndProc(hWnd, message, wParam, lParam):

    if message == win32con.WM_PAINT:
        hDC, paintStruct = win32gui.BeginPaint(hWnd)

        rect = win32gui.GetClientRect(hWnd)
        win32gui.DrawText(
            hDC,
            'Hello send by Python via Win32!',
            -1,
            rect,
            win32con.DT_SINGLELINE | win32con.DT_CENTER | win32con.DT_VCENTER)

        win32gui.EndPaint(hWnd, paintStruct)
        return 0

    elif message == win32con.WM_DESTROY:
        print('Closed!')
        win32gui.PostQuitMessage(0)
        return 0

    else:
        return win32gui.DefWindowProc(hWnd, message, wParam, lParam)



if __name__ == '__main__':
    main()