Question

我尝试通过Tkinter进行GUI。此代码如下目标是每1秒显示消息“此页面xxx”。当我打开每一帧时

当我打开第一页时，将每1秒显示一条消息“这是第一页”
当我打开第二页时，会每1秒显示一条消息“这是第二页”（不显示消息第一页）

（对不起，我解释英语不好）

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

您的代码中存在一些问题。

首先，在StartPage.gopagetwo中，PageTwo.mymessage()的调用不起作用，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frame.mymessage()中添加对Application.show_frame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，而是针对每个访问过的帧（以及一个访问过的帧）打印消息。如果您按照此轨道进行操作，则必须将after的绑定存储在某处，并提供中止它的选项。

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)

并调整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

<小时/> 但是，您可能会发现只有一个后循环的实例更简单，它将print语句委托给您的帧（并在每个mymessage中删除循环）。

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)

Tkinter Multiframe事件

1 个答案: