Tkinter开关架

Question

我使用以下代码：

Switch between two frames in tkinter

import RPi.GPIO as GPIO
from threading import Timer,Thread,Event

import tkinter as tk                # python 3
from tkinter import font  as tkfont # python 3
#import Tkinter as tk     # python 2
#import tkFont as tkfont  # python 2

#----------------------------------------------------------
#Setup GPIO
#----------------------------------------------------------
GPIO.setwarnings(False)
# RPi.GPIO Layout verwenden (wie Pin-Nummern)
#GPIO.setmode(GPIO.BOARD)
GPIO.setmode(GPIO.BCM)

# (GPIO 17,27,22,5) auf Input setzen
chan_list1 = [17, 27, 22, 5]
GPIO.setup(chan_list1, GPIO.IN, pull_up_down=GPIO.PUD_UP)

# (GPIO 12,13,23,24) auf Output setzen
chan_list = [12, 13, 23, 24]
GPIO.setup(chan_list, GPIO.OUT)
#----------------------------------------------------------

#--------------------------------------------------------
#Timer
#--------------------------------------------------------
class perpetualTimer():

   def __init__(self,t,hFunction):
      self.t=t
      self.hFunction = hFunction
      self.thread = Timer(self.t,self.handle_function)

   def handle_function(self):
      self.hFunction()
      self.thread = Timer(self.t,self.handle_function)
      self.thread.start()

   def start(self):
      self.thread.start()

   def cancel(self):
      self.thread.cancel()
#--------------------------------------------------------



class SampleApp(tk.Tk):

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

        self.overrideredirect(1)              #Remove Title bar  
        self.geometry("480x272")              #Set the window dimensions

        self.title_font = tkfont.Font(family='Helvetica', size=18, weight="bold", slant="italic")

        # the container is where we'll stack a bunch of frames
        # on top of each other, then the one we want visible
        # will be raised above the others
        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 (StartPage, PageOne, PageTwo):
            page_name = F.__name__
            frame = F(parent=container, controller=self)
            self.frames[page_name] = frame

            # put all of the pages in the same location;
            # the one on the top of the stacking order
            # will be the one that is visible.
            frame.grid(row=0, column=0, sticky="nsew")

        self.show_frame("StartPage")

    def show_frame(self, page_name):
        '''Show a frame for the given page name'''
        frame = self.frames[page_name]
        frame.tkraise()


class StartPage(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        self.controller = controller
        label = tk.Label(self, text="This is the start page", font=controller.title_font)
        label.pack(side="top", fill="x", pady=10)

        button1 = tk.Button(self, text="Go to Page One",
                            command=lambda: controller.show_frame("PageOne"))
        button2 = tk.Button(self, text="Go to Page Two",
                            command=lambda: controller.show_frame("PageTwo"))
        button1.pack()
        button2.pack()


class PageOne(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        self.controller = controller
        label = tk.Label(self, text="This is page 1", font=controller.title_font)
        label.pack(side="top", fill="x", pady=10)
        button = tk.Button(self, text="Go to the start page",
                           command=lambda: controller.show_frame("StartPage"))
        button.pack()


class PageTwo(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        self.controller = controller
        label = tk.Label(self, text="This is page 2", font=controller.title_font)
        label.pack(side="top", fill="x", pady=10)
        button = tk.Button(self, text="Go to the start page",
                           command=lambda: controller.show_frame("StartPage"))
        button.pack()



def printer():
    print ('PIT(!)')
    SampleApp.show_frame('PageOne') 
if __name__ == "__main__":
    t = perpetualTimer(0.01,printer)
    t.start()

    app = SampleApp()
    app.mainloop()

是否可以在不使用按钮的情况下切换框架？ 例如比较一个计数器。如果计数器值为1，则显示第1页 如果计数器值为2，请显示第2页，依此类推。

说实话，我不记得我曾经尝试过的所有内容。 我尝试过的一件事是def打印机子程序中的“ controller.show_frame（“ StartPage”）”。 我要实现的是从“ def printer”子菜单中切换页面， 这是定期调用的。 我不知道那有可能吗？

Answer 1

  

我尝试过的一件事是从def打印机子机上controller.show_frame("StartPage")。

您必须在具有该方法的对象上调用switch_frame。这与python中的任何其他对象或任何其他类没有什么不同。

在您的情况下，由于SampleApp是具有该方法的类，而app是包含该类实例的全局变量，因此您可以这样做：

app.show_frame("StartPage")