Question

我正在尝试制作一个包含多个带按钮和标签页面的GUI程序。我需要程序能够通过按下按钮动态更改标签与我目前没有工作的页面上的标签进行交互。我已经制作了一个运行的示例程序，但是在尝试更改未显示的页面中的标签时出现错误。

import tkinter as tk
from tkinter import ttk

LARGE_FONT = ("Verdana", 12)


class ManyPagesApp(tk.Tk):

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

        # This loop adds the pages into the frame
        for F in (Page1, Page2):
            frame = F(container, self)
            self.frames[F] = frame
            frame.grid(row=0, column=0, sticky="nsew")
        self.show_frame(Page1)

    # This function raises the page to the "top" level of the frame
    def show_frame(self, cont):
        frame = self.frames[cont]
        frame.tkraise()


# Creates what shows in start page
class Page1(tk.Frame):

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

        button1 = ttk.Button(self, text="Go to Page 2", command=lambda: controller.show_frame(Page2))
        button1.pack()

        button2 = ttk.Button(self, text="THIS BUTTON CHANGES LABEL ON PAGE 1",
                         command=lambda: self.labelChanger('This label was changed by using button 2'))
        button2.pack()

        label = ttk.Label(self, text='This is Page 1', font=LARGE_FONT)
        label.pack(pady=10, padx=10)

        self.labelVariable1 = tk.StringVar()
        self.labelVariable1.set('This label will be changed')
        label = tk.Label(self, textvariable= self.labelVariable1)
        label.pack()

    def labelChanger(self, text):
        self.labelVariable1.set(text)

class Page2(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        objectofpage1 = Page1

        button1 = ttk.Button(self, text="Goes to page 1", command=lambda: controller.show_frame(Page1))
        button1.pack()

        button2 = ttk.Button(self, text="Changes Label 2 in page 1",
                         command=lambda: objectofpage1.labelChanger(objectofpage1, 'You have changed the label in page 1'))
        button2.pack()

        label = ttk.Label(self, text='This is page 2', font=LARGE_FONT)
        label.pack(pady=10, padx=10)



# Runs everything
if __name__ == "__main__":
    app = ManyPagesApp()
    app.mainloop()

由于有更多页面，我的应用程序变得更大但我制作了这个示例程序，它给了我同样的错误。

OBS：只有在第2页上尝试更改第1页上的标签时才会出现错误。

这是弹出的错误：

Exception in Tkinter callback
Traceback (most recent call last):
File "***\Python35-32\lib\tkinter\__init__.py", line 1549, in __call__
return self.func(*args)
  File "***/TestApp.py", line 63, in <lambda>
command=lambda: objectofpage1.labelChanger(objectofpage1, 'You have changed the label in page 1'))
  File "***/TestApp.py", line 51, in labelChanger
self.labelVariable1.set(text)
AttributeError: type object 'Page1' has no attribute 'labelVariable1'

PS：第一次发帖，我不知道这是否已经得到解答，但我找不到任何解决这个问题的方法，所以我创建了一个账号来发帖。

我很感激帮助，并提前致谢！

Answer 1

错误在于此声明：

objectofpage1 = Page1

您正在将objectofpage1设置为类，而不是类的实例。您的程序已经有一个实例，您只需要获取由控制器管理的实例。

如果每个页面都需要访问其他页面，则只需向控制器添加一个方法即可返回实例。像这样：

class ManyPagesApp(tk.Tk):
    ...
    def get_page(self, page_class):
        return self.frames[page_class]

class Page2(tk.Frame):

    def __init__(self, parent, controller):
        ...
        objectofpage1 = controller.get_page(Page1)

注意：您在此声明中也有一个错误：

command=lambda: objectofpage1.labelChanger(objectofpage1, 'You have changed the label in page 1'))

应该是：

command=lambda: objectofpage1.labelChanger('You have changed the label in page 1'))

有关在页面之间共享信息的更全面讨论，请参阅How to get variable data from a class

AttributeError：类型对象'class'没有属性'stringVar'

1 个答案: