尝试重复使用Python中的Windows Notification类时出错

Question

我试图在玩我的游戏时使用pywin32模块创建更多的交互式体验，但遇到了一些问题。我希望多次使用类WindowsBalloonTip，但在尝试再次使用时遇到问题。

class WindowsBalloonTip: 
    def __init__(self, title, msg): 
     message_map = { 
       win32con.WM_DESTROY: self.OnDestroy, 
     } 
     # Register the Window class. 
     wc = WNDCLASS() 
     hinst = wc.hInstance = GetModuleHandle(None) 
     wc.lpszClassName = "PythonTaskbar" 
     wc.lpfnWndProc = message_map # could also specify a wndproc. 
     classAtom = RegisterClass(wc) 
     # Create the Window. 
     style = win32con.WS_OVERLAPPED | win32con.WS_SYSMENU 
     self.hwnd = CreateWindow(classAtom, "Taskbar", style, \ 
       0, 0, win32con.CW_USEDEFAULT, win32con.CW_USEDEFAULT, \ 
       0, 0, hinst, None) 
     UpdateWindow(self.hwnd) 
     iconPathName = os.path.abspath(os.path.join(sys.path[0], "balloontip.ico")) 
     icon_flags = win32con.LR_LOADFROMFILE | win32con.LR_DEFAULTSIZE 
     try: 
      hicon = LoadImage(hinst, iconPathName, \ 
        win32con.IMAGE_ICON, 0, 0, icon_flags) 
     except: 
      hicon = LoadIcon(0, win32con.IDI_APPLICATION) 
     flags = NIF_ICON | NIF_MESSAGE | NIF_TIP 
     nid = (self.hwnd, 0, flags, win32con.WM_USER+20, hicon, "tooltip") 
     Shell_NotifyIcon(NIM_ADD, nid) 
     Shell_NotifyIcon(NIM_MODIFY, \ 
         (self.hwnd, 0, NIF_INFO, win32con.WM_USER+20,\ 
          hicon, "Balloon tooltip",msg,200,title)) 
     # self.show_balloon(title, msg) 
     DestroyWindow(self.hwnd) 
    def OnDestroy(self, hwnd, msg, wparam, lparam): 
     nid = (self.hwnd, 0) 
     Shell_NotifyIcon(NIM_DELETE, nid) 
     PostQuitMessage(0) # Terminate the app. 

def balloon_tip(title, msg): 
    w=WindowsBalloonTip(title, msg) 

要在WindowsBalloonTip打电话，我使用：

balloon_tip("Fantasy Text", "Welcome to Fantasy Text!") 

可是后来，当我试图再次使用balloon_tip上，我遇到这个错误：

Traceback (most recent call last): 
    File "C:\Users\austin\Documents\Programming\Fantasy Text\v1.0.1.0\Fantasy Text.py", line 456, in <module> 
    Start() 
    File "C:\Users\austin\Documents\Programming\Fantasy Text\v1.0.1.0\Fantasy Text.py", line 89, in Start 
    Zombie_Mode() 
    File "C:\Users\austin\Documents\Programming\Fantasy Text\v1.0.1.0\Fantasy Text.py", line 224, in Zombie_Mode 
    Zombie_Attack() 
    File "C:\Users\austin\Documents\Programming\Fantasy Text\v1.0.1.0\Fantasy Text.py", line 240, in Zombie_Attack 
    balloon_tip("FT: Zombie", "Zombie did %s" % zombie_damage + ' damage!') 
    File "C:\Users\austin\Documents\Programming\Fantasy Text\v1.0.1.0\Fantasy Text.py", line 60, in balloon_tip 
    w=WindowsBalloonTip(title, msg) 
    File "C:\Users\austin\Documents\Programming\Fantasy Text\v1.0.1.0\Fantasy Text.py", line 32, in __init__ 
    classAtom = RegisterClass(wc) 
pywintypes.error: (1410, 'RegisterClass', 'Class already exists.') 

我意识到，类已经存在的错误给出，但我该如何解决这个问题？

Answer 1

只是重构你的代码。创建WindowsBalloonTip一个实例，并用它来显示你所有的技巧：

class WindowsBalloonTip: 
    def __init__(self): 
     message_map = { 
       win32con.WM_DESTROY: self.OnDestroy, 
     } 
     # Register the Window class. 
     wc = WNDCLASS() 
     self.hinst = wc.hInstance = GetModuleHandle(None) 
     wc.lpszClassName = "PythonTaskbar" 
     wc.lpfnWndProc = message_map # could also specify a wndproc. 
     self.classAtom = RegisterClass(wc) 

    def ShowWindow(self,title, msg): 
     # Create the Window. 
     style = win32con.WS_OVERLAPPED | win32con.WS_SYSMENU 
     self.hwnd = CreateWindow(self.classAtom, "Taskbar", style, \ 
       0, 0, win32con.CW_USEDEFAULT, win32con.CW_USEDEFAULT, \ 
       0, 0, self.hinst, None) 
     UpdateWindow(self.hwnd) 
     iconPathName = os.path.abspath(os.path.join(sys.path[0], "balloontip.ico")) 
     icon_flags = win32con.LR_LOADFROMFILE | win32con.LR_DEFAULTSIZE 
     try: 
      hicon = LoadImage(self.hinst, iconPathName, \ 
        win32con.IMAGE_ICON, 0, 0, icon_flags) 
     except: 
      hicon = LoadIcon(0, win32con.IDI_APPLICATION) 
     flags = NIF_ICON | NIF_MESSAGE | NIF_TIP 
     nid = (self.hwnd, 0, flags, win32con.WM_USER+20, hicon, "tooltip") 
     Shell_NotifyIcon(NIM_ADD, nid) 
     Shell_NotifyIcon(NIM_MODIFY, \ 
         (self.hwnd, 0, NIF_INFO, win32con.WM_USER+20,\ 
          hicon, "Balloon tooltip",msg,200,title)) 
     # self.show_balloon(title, msg) 
     DestroyWindow(self.hwnd) 

    def OnDestroy(self, hwnd, msg, wparam, lparam): 
     nid = (self.hwnd, 0) 
     Shell_NotifyIcon(NIM_DELETE, nid) 
     PostQuitMessage(0) # Terminate the app. 

w = WindowsBalloonTip() 
w.ShowWindow("Title1","Message One!") 
time.sleep(1) # some time later 
w.ShowWindow("Title2","Message Two!")