tkinter-当帧显示后运行函数

Question

下面的代码在OtherPage类中有一个onShowFrame函数，该函数在显示OtherPage框架时运行。我的问题是onShowFrame函数中的所有内容都在帧实际显示给用户之前运行。我用time.sleep(5)演示了这一点。在显示OtherPage帧之前，程序会在空白页上休眠5秒。我希望首先显示OtherPage框架，然后运行onShowFrame函数中的任何内容。在

我该怎么做？在

import tkinter as tk
import time

class Program(tk.Tk):        
    def __init__(self, *args, **kwargs):
        tk.Tk.__init__(self, *args, **kwargs)

        tk.Tk.iconbitmap(self, default = "")
        tk.Tk.wm_title(self, "")

        container = tk.Frame(self)
        container.pack(side="top", fill="both", expand=True)
        container.grid_rowconfigure(0, weight=1)
        container.grid_columnconfigure(0, weight=1)

        self.frames = {}
        for F in (BlankPage, OtherPage):

            frame = F(container, self)
            self.frames[F] = frame
            frame.grid(row = 0, column = 0, sticky = "nsew")

        self.showFrame(BlankPage)

    def showFrame(self,cont):
        frame = self.frames[cont]
        frame.tkraise()
        frame.event_generate("<<ShowFrame>>")

###########################################################################################################
class OtherPage(tk.Frame):
    def __init__(self, parent, controller):

        self.controller = controller
        tk.Frame.__init__(self, parent)

        innerFrame = tk.Frame(self)
        innerFrame.place(relx=.5, rely=.5, anchor="c", relwidth=1.0, relheight=1.0)

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

        self.frameOne = tk.Frame(innerFrame)
        self.frameOne.grid()

        label = tk.Label(self.frameOne, text = "Other Page")
        label.pack()

        self.bind("<<ShowFrame>>", self.onShowFrame)

    def onShowFrame(self, event):
        time.sleep(5)

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

class BlankPage(tk.Frame):
    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)

        innerFrame = tk.Frame(self)
        innerFrame.place(relx=.5, rely=.5, anchor="c", relwidth=1.0, relheight=1.0)

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

        self.frameOne = tk.Frame(innerFrame)
        self.frameOne.grid()

        button = tk.Button(self.frameOne, text = "Press", command = lambda: controller.showFrame(OtherPage))
        button.pack()

app = Program()
app.state('zoomed')
app.mainloop()

Answer 1

这个问题与您调用sleep这会导致应用程序睡眠。为了更新显示，事件循环必须能够处理事件，而这在休眠时无法处理。睡眠的字面意思是停止所有的处理。time.sleep文档的前六个字是挂起当前线程的执行。在

在这个地方，对小部件调用update是一件合理的事情。它将使tkinter有机会在生成新事件之前处理所有未决事件，如处理按钮单击的完成、重新绘制窗口等。在

只需将您的功能更改为如下所示：

def showFrame(self,cont):
    frame = self.frames[cont]
    frame.tkraise()
    frame.update()
    frame.event_generate("<<ShowFrame>>")