python - 无法从其他类访问变量 - tkinter

Question

我正在尝试在 tkinter 中编写一个程序，用户单击带有其姓名的按钮，然后验证页面会向他们显示该程序。我遇到的问题是变量要么正在重置，要么我访问错误:

import tkinter as tk
from tkinter import *
from tkinter import ttk

LARGE_FONT = ("Times New Roman", 12)
NORM_FONT = ("Times New Roman", 10)
root = Tk()
root.withdraw()


class DIS(tk.Tk):

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

        tk.Tk.__init__(self, *args, **kwargs)
        tk.Tk.iconbitmap(self, default="")
        tk.Tk.wm_title(self, "program")
        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, contactQues, nameVerify):

            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()


class StartPage(tk.Frame):

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

        button2 = ttk.Button(self, text = "Name Select",
                        command=lambda:           controller.show_frame(contactQues))
        button2.pack()


class contactQues(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)  
        self.controller = controller
        global name
        name = StringVar()

        label1 = tk.Label(self, text = "Select Your Name", font = LARGE_FONT)
        label1.pack(pady=10, padx=10)

        button2 = ttk.Button(self, text = "Bojangles", command = self.bojangles)
        button2.pack(pady=5)

    def bojangles(self):

        name.set("Mr. Bojangles")
        self.controller.show_frame(nameVerify)
    #
    #Many other names to select
    #

class nameVerify(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        self.controller = controller
        namename = name.get()

        label5 = tk.Label(self, text = "Your Name:", font = LARGE_FONT)
        label5.pack(pady=10, padx=10)
        labelcontact = tk.Label(self, text = namename, font = NORM_FONT)
        labelcontact.pack()

app = DIS()
app.mainloop()

所以，本质上，我想要发生的是: - 程序运行，用户按下“名称选择”，用户选择他们的名称，最后一页显示他们的选择。

我尝试过使用全局变量、labelcontact 标签的文本变量、StringVar() 等，但似乎无法确定这一点。

有更好的方法吗？或者我做错了什么？

感谢您的帮助。

Answer 1

我建议将 name 设为 DIS 类的属性。然后您的 StartPage 和 nameVerify 实例可以通过其 controller 属性访问它。如果您希望 labelcontact 在 name 更新时自动更新，请使用 textvariable 属性。

此外，您需要删除 root = Tk() 和 root.withdraw() 行。我不知道为什么，但只要它们在那里，labelcontact 标签就不会正确更新。在任何情况下它们似乎都没有做任何事情 - 希望它们对您的实际代码并不重要。

import tkinter as tk
from tkinter import *
from tkinter import ttk

LARGE_FONT = ("Times New Roman", 12)
NORM_FONT = ("Times New Roman", 10)

class DIS(tk.Tk):

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

        tk.Tk.__init__(self, *args, **kwargs)
        tk.Tk.iconbitmap(self, default="")
        tk.Tk.wm_title(self, "program")
        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.name = StringVar()
        self.frames = {}

        for F in (StartPage, contactQues, nameVerify):

            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()


class StartPage(tk.Frame):

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

        button2 = ttk.Button(self, text = "Name Select",
                        command=lambda:           controller.show_frame(contactQues))
        button2.pack()


class contactQues(tk.Frame):

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

        label1 = tk.Label(self, text = "Select Your Name", font = LARGE_FONT)
        label1.pack(pady=10, padx=10)

        button2 = ttk.Button(self, text = "Bojangles", command = self.bojangles)
        button2.pack(pady=5)

    def bojangles(self):

        self.controller.name.set("Mr. Bojangles")
        self.controller.show_frame(nameVerify)
    #
    #Many other names to select
    #

class nameVerify(tk.Frame):

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

        label5 = tk.Label(self, text = "Your Name:", font = LARGE_FONT)
        label5.pack(pady=10, padx=10)
        labelcontact = tk.Label(self, textvariable = self.controller.name, font = NORM_FONT)
        labelcontact.pack()

app = DIS()
app.mainloop()