如何在 python 中使用 ctypes 在消息框中包含图像

Question

我正在 windows 7 64 位机器上的 python 2.7 中制作一个消息框。它将在消息框中向用户显示错误消息。

import ctypes

msgbox = ctypes.windll.user32.MessageBoxA
ret = msgbox(None, 'message', 'title', 0)
print ret

这会显示所需的消息框。但是在任务栏中会出现python的默认图像，这很烦人。那么，如何在任务栏中包含图像。或者只是不在任务栏中显示 python 的默认图像。

Answer 1

这是因为你没有窗口，None，然后系统会分配一个默认图标。

您可以使用SetWindowsHookEx 安装挂钩，然后更改MessageBox 图标。例如让我们使用StackOverflow icon。

#-*- coding: utf-8 -*-
#!python


from ctypes import *
from ctypes.wintypes import *
#recommended
#from ctypes import windll, c_int, c_int64, c_long, WINFUNCTYPE, POINTER, cast, c_wchar, byref
#from ctypes.wintypes import HMODULE, LPCWSTR, HANDLE, HINSTANCE, UINT, HWND, WPARAM, LPARAM, HHOOK, DWORD, BOOL, RECT, POINT
from os import path
import platform

#################################################################

RelPath = lambda file : path.join(path.dirname(path.abspath(__file__)), file)

#################################################################

GetModuleHandle = windll.kernel32.GetModuleHandleW
GetModuleHandle.restype = HMODULE
GetModuleHandle.argtypes = [LPCWSTR]

#################################################################

IMAGE_ICON = 1
LR_LOADFROMFILE = 0x00000010
LR_CREATEDIBSECTION = 0x00002000

LoadImage = windll.user32.LoadImageW
LoadImage.restype = HANDLE
LoadImage.argtypes = [HINSTANCE, LPCWSTR, UINT, c_int, c_int, UINT]

#################################################################

LRESULT = c_int64 if platform.architecture()[0] == "64bit" else c_long

SendMessage = windll.user32.SendMessageW
SendMessage.restype = LRESULT
SendMessage.argtypes = [HWND, UINT, WPARAM, LPARAM]

#################################################################

MB_OK = 0x00000000L 

MessageBox = windll.user32.MessageBoxW
MessageBox.restype  = c_int
MessageBox.argtypes = [HWND, LPCWSTR, LPCWSTR, UINT]

#################################################################

WH_CBT = 5
HCBT_ACTIVATE = 5
HOOKPROC = WINFUNCTYPE(LRESULT, c_int, WPARAM, LPARAM)

SetWindowsHookEx = windll.user32.SetWindowsHookExW
SetWindowsHookEx.restype = HHOOK
SetWindowsHookEx.argtypes = [c_int, HOOKPROC, HINSTANCE, DWORD]

#################################################################

CallNextHookEx = windll.user32.CallNextHookEx
CallNextHookEx.restype = LRESULT
CallNextHookEx.argtypes = [HHOOK, c_int, WPARAM, LPARAM]

#################################################################

GetCurrentThreadId = windll.kernel32.GetCurrentThreadId
GetCurrentThreadId.restype = DWORD
GetCurrentThreadId.argtypes = None

#################################################################

UnhookWindowsHookEx = windll.user32.UnhookWindowsHookEx
UnhookWindowsHookEx.restype = BOOL
UnhookWindowsHookEx.argtypes = [HHOOK]

#################################################################
# code starts here

def MyMessageBox(hWnd, lpText, lpCaption, uType, lpIcon):
  hHook = HHOOK(None)

  #**********************************************************#
    # center button code
  def EnumChildProc(hwnd, lParam):
    ClassName = (c_wchar * 7)()
    if GetClassName(hwnd, ClassName, 7) > 0:
      if ClassName.value.lower() == "button":
        wrect = RECT()
        GetClientRect(lParam, byref(wrect))
        brect = RECT()
        GetClientRect(hwnd, byref(brect))
        bpoint = RECT()
        MapWindowPoints(hwnd, lParam, cast(byref(bpoint), POINTER(POINT)), 2)
        MoveWindow(hwnd,
                  ((wrect.right - wrect.left) - (brect.right - brect.left)) // 2,
                  bpoint.top,
                  brect.right - brect.left,
                  brect.bottom - brect.top,
                  True)
        return False
    return True
    
  WNDENUMPROC = WINFUNCTYPE(BOOL, HWND, LPARAM)

  EnumChildWindows = windll.user32.EnumChildWindows
  EnumChildWindows.restype = BOOL
  EnumChildWindows.argtypes = [HWND, WNDENUMPROC, LPARAM]

  GetClassName = windll.user32.GetClassNameW
  GetClassName.restype = HWND
  GetClassName.argtypes = [HWND, LPCWSTR, c_int]

  GetClientRect = windll.user32.GetClientRect 
  GetClientRect.restype = BOOL
  GetClientRect.argtypes = [HWND, POINTER(RECT)]
  
  MoveWindow = windll.user32.MoveWindow
  MoveWindow.restype = BOOL
  MoveWindow.argtypes = [HWND, c_int, c_int, c_int, c_int, BOOL]
  
  MapWindowPoints = windll.user32.MapWindowPoints
  MapWindowPoints.restype = c_int
  MapWindowPoints.argtypes = [HWND, HWND, POINTER(POINT), UINT]
    
  #**********************************************************#

  def AlterIcon(_hWnd, lpszIcon):

    WM_SETICON = 0x0080
    ICON_BIG = 1

    hModel = GetModuleHandle(None)
    hIcon = LoadImage(hModel,
                      RelPath(lpszIcon),
                      IMAGE_ICON,
                      0, 0,
                      LR_LOADFROMFILE | LR_CREATEDIBSECTION)


    SendMessage(_hWnd, WM_SETICON, ICON_BIG, hIcon)

  def CBTProc(nCode, wParam, lParam):
    if nCode == HCBT_ACTIVATE:
      _hWnd = cast(wParam, HWND)
      AlterIcon(_hWnd, lpIcon)
      #**********************************************************#
      pEnumChildProc = WNDENUMPROC(EnumChildProc)
      EnumChildWindows(_hWnd, pEnumChildProc, _hWnd.value)
      #**********************************************************#

    CallNextHookEx(hHook, nCode, wParam, lParam)
    return 0

  # WARNING: don't pass HOOKPROC(CBTProc) directly to SetWindowsHookEx
  pCBTProc = HOOKPROC(CBTProc)

  hHook = SetWindowsHookEx(WH_CBT, pCBTProc, None, GetCurrentThreadId())

  MessageBox(hWnd, lpText, lpCaption, uType)

  UnhookWindowsHookEx(hHook)

# example of usage
MyMessageBox(None, "Hello world!", "Title", MB_OK, "favicon.ico")

大部分代码只是函数原型。现在您可以拨打MyMessageBox 为：

MyMessageBox(None, "Hello world!", "Title", MB_OK, "favicon.ico")

结果：

更新：它现在将通过枚举消息框窗口的冷却器并寻找一个按钮，然后将其居中来居中按钮。我没有对其进行太多测试，但到目前为止看起来还不错。