在Tkinter中重叠不同的帧

Question

I'm trying to make a calculator and it has different frames ie Basic, Statistics, ..., etc. However, I'm having issues to show each frame.

This is the container for all the frames (I took a code of a previous post as example)

import tkinter as tk

class calculatorframe(tk.Tk):
    def __init__(self, *args, **kwargs):
        tk.Tk.__init__(self, *args, **kwargs)
        #----------------CONTAINER FOR ALL THE FRAMES----------
        container = tk.Frame(self)
        container.pack()
        #--------------------- DROPDOWN MENU------------------

        tkvar = tk.StringVar()
        choices={'Basic Mode','Calculus Mode'} #Options of the dropdown menu
        tkvar.set('Basic Mode') #default frame
        dropdownmenu =tk.OptionMenu(container, tkvar, *choices)
        dropdownmenu.grid(row=2,column=3) #position of the dropdown menu

        self.frames = {}


        for F in (Basic, Calculus):
            page_name = F.__name__
            frame = F(parent= container, controller=self)
            self.frames[page_name] = frame

            frame.grid(row=0, column=0, sticky= "nsew")

        self.show_frame('Basic')

    #-------FUNCTION TO SHOW THE CURRENT FRAME

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

These are the classes that I created for the basic calculator

class Basic(tk.Frame):

    def __init__(self, parent, controller):
        #--------------- SCREEN ---------------
        tk.Frame.__init__(self, parent)
        screen = tk.Entry(self, width=80)  
        screen.grid(row=3, column=1,columnspan=7) #position of the screen
        #------------ BUTTON ---------------------
        button7=tk.Button(self, text="7", width=8)  #button
        button7.grid(row=4,column=1)
#---------------------frame for calculus -------------------------
class Calculus(tk.Frame):
    def __init__(self, parent, controller):
            tk.Frame.__init__(self, parent)
            #-----------------------------SCREEN------------
            screen=tk.Entry(self, width=50)
            screen.pack()
            screen.grid(row=3, column=1, pady=20, columnspan=7) #position of the screen
            #------------------------BUTTON---------------
            go=tk.Button(self, height=1, text="Go") #button
            go.grid(row=1, column=8)


if __name__ == "__main__":
    app = calculatorframe()
    app.mainloop()

I'm aware that I have to keep track of the value of tkvar and that I need to do it using trace() and pass that value to show_frame, however, I don't know where to place it in my code. I tried to put it below the dropdown menu, but I get an error message and I tried after the function show_frame and it did not work either. I'm a bit stuck, I would really appreciate your help, thanks in advance.

Answer 1

The simple solution would be to add a command to your OptionsMenu() function. We will also need to change your class names and your choice options due to how the command argument works here.

For the OptionsMenu() command argument when you tell it to call a method it will automatically pass the value of the selected item in the drop down. So because of this we need to make sure our selection reflect the class names. You can change the choices/classes to be whatever you wish I just used BasicMode and CalculusMode as an example.

The command will automatically pass the value selected so we can use that to call each frame using you show_frame method.

Take a look at the below code and let me know if you have any questions.

import tkinter as tk


class calculatorframe(tk.Tk):
    def __init__(self, *args, **kwargs):
        tk.Tk.__init__(self, *args, **kwargs)
        container = tk.Frame(self)
        container.pack()

        tkvar = tk.StringVar()
        choices = {'BasicMode', 'CalculusMode'}
        tkvar.set('BasicMode')
        dropdownmenu = tk.OptionMenu(container, tkvar, *choices, command=self.show_frame)
        dropdownmenu.grid(row=2, column=3)

        self.frames = {}

        for F in (BasicMode, CalculusMode):
            page_name = F.__name__
            frame = F(parent= container, controller=self)
            self.frames[page_name] = frame

            frame.grid(row=0, column=0, sticky="nsew")

        self.show_frame('BasicMode')

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


class BasicMode(tk.Frame):
    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        screen = tk.Entry(self, width=80)  
        screen.grid(row=3, column=1, columnspan=7)

        button7 = tk.Button(self, text="7", width=8)
        button7.grid(row=4,column=1)


class CalculusMode(tk.Frame):
    def __init__(self, parent, controller):
            tk.Frame.__init__(self, parent)
            screen = tk.Entry(self, width=50)
            screen.pack()
            screen.grid(row=3, column=1, pady=20, columnspan=7)
            go = tk.Button(self, height=1, text="Go")
            go.grid(row=1, column=8)


if __name__ == "__main__":
    app = calculatorframe()
    app.mainloop()