Tkinter多帧事件

Question

我尝试通过Tkinter GUI。该代码如下， 目标是每1秒显示消息“本页xxx”。当我打开每个帧相同

1. 当我打开一个页面将显示消息“这是一个网页”每隔1秒
2. 当我打开两个页面将显示消息“这是两页的”每1第二（不显示消息页面之一）

（对不起我的所有解释英语不太好）

import Tkinter as tk 
LARGE_FONT= ("Verdana", 12) 

class Application(tk.Tk): 

    def __init__(self, *args, **kwargs): 

     tk.Tk.__init__(self, *args, **kwargs) 
     container = tk.Frame(self, bg='red') 
     container.pack(side="top", fill="both", expand = True) 

     self.val1 = "chain" 

     container.grid_rowconfigure(0, weight=1) 
     container.grid_columnconfigure(0, weight=1) 

     self.frames = {} 
     self.collection = (StartPage, PageOne, PageTwo) 

     for F in self.collection: 
      frame = F(container, self) 
      self.frames[F] = frame 
      frame.grid(row=0, column=0, sticky="nsew") 
     self.show_frame(StartPage) 

    def show_frame(self, cont): 
     frame = self.frames[cont] 
     frame.tkraise() 

    def printdata(self, data): 
     print data 


class StartPage(tk.Frame): 

    def __init__(self, parent, controller): 
     tk.Frame.__init__(self,parent) 
     self.master = controller 
     self.configure(background='green') 
     label = tk.Label(self, text="Start Page", font=LARGE_FONT) 
     label.pack(pady=10,padx=10) 

     button = tk.Button(self, text="Visit Page 1", command=lambda: controller.show_frame(PageOne)) 
     button.pack() 

     button2 = tk.Button(self, text="Visit Page 2", command=lambda: self.gopagetwo()) 
     button2.pack() 

    def gopagetwo(self): 
     PageTwo.mymessage() 
     self.master.show_frame(PageTwo) 

    def mymessage(self): 
     print 'This is page initial.' 
     self.after(1000, self.mymessage) 


class PageOne(tk.Frame): 

    def __init__(self, parent, controller): 
     tk.Frame.__init__(self, parent, bg='yellow') 
     self.master = controller 
     self.label = tk.Label(self, text="Page One!!!", font=LARGE_FONT) 
     self.label.pack(pady=5,padx=10) 
     self.lblCounter = tk.Label(self, text="Counter", font=LARGE_FONT) 
     self.lblCounter.pack(pady=5,padx=10) 
     self.lblStartTime = tk.Label(self, text="time start", font=LARGE_FONT) 
     self.lblStartTime.pack(pady=5,padx=10) 
     self.lblStartNow = tk.Label(self, text="time now", font=LARGE_FONT) 
     self.lblStartNow.pack(pady=5,padx=10) 

     button1 = tk.Button(self, text="Back to Home", 
          command=lambda: controller.show_frame(StartPage)) 
     button1.pack() 

    def mymessage(self): 
     print 'This is page one.' 
     self.after(1000, self.mymessage) 


class PageTwo(tk.Frame): 

    def __init__(self, parent, controller): 
     tk.Frame.__init__(self, parent, bg='pink') 
     self.master = controller 
     label = tk.Label(self, text="Page Two!!!", font=LARGE_FONT) 
     label.pack(pady=5,padx=10) 
     self.lblCounter = tk.Label(self, text="Counter", font=LARGE_FONT) 
     self.lblCounter.pack(pady=5,padx=10) 
     self.lblStartTime = tk.Label(self, text="time start", font=LARGE_FONT) 
     self.lblStartTime.pack(pady=5,padx=10) 
     self.lblStartNow = tk.Label(self, text="time now", font=LARGE_FONT) 
     self.lblStartNow.pack(pady=5,padx=10) 

     button1 = tk.Button(self, text="Back to Home", 
          command=lambda: controller.show_frame(StartPage)) 
     button1.pack() 

    def mymessage(self): 
     print 'This is page two.' 
     self.after(1000, self.myssage) 


app = Application() 
app.mainloop() 

Answer 1

有代码中的几个问题。

首先，在StartPage.gopagetwo中，调用PageTwo.mymessage()无法工作，因为mymessage是一个实例方法，它需要一个PageTwo实例才能正常工作。

您可以尝试通过在Application.show_frame中添加对frame.mymessage()的调用来达到您想要的行为。但是，您会发现它不会为当前帧打印消息，而是会为每个访问帧（并通过访问）打印一条消息。如果你遵循这个轨道，你将不得不在某个地方存储以后的绑定，并提供一个中止它的选项。

class StartPage(tk.Frame): 
    #... 
    def mymessage(self): 
     print 'This is page initial.' 
     self.after_id = self.after(1000, self.mymessage) 

    def end_mymessageloop(self): 
     self.after_cancel(self.after_id) 

和适应show_frame：

class Application(tk.Tk): 
    #... 
    def show_frame(self, cont): 
     if hasattr(self,"current_frame"): 
      self.current_frame.end_mymessageloop() 
     frame = self.frames[cont] 
     frame.tkraise() 
     frame.mymessage() 
     self.current_frame = frame 

---

然而，你可能会发现简单的只具有循环结束后的这一个实例委托print语句的帧（并删除在后循环每个mymessage）。

class Application(tk.Tk): 
    def __init__(self, *args, **kwargs): 
     #... 
     self.show_frame(StartPage) 
     self.status_message() 

    def show_frame(self, cont): 
     frame = self.frames[cont] 
     frame.tkraise() 
     self.current_frame = frame 

    def status_message(self): 
     self.current_frame.mymessage() 
     self.after(1000, self.status_message)