仍在与 class 范围作斗争

Question

我还没有完全理解 classes 的范围。我已经阅读了这篇文章，并且我一直在尝试做不同的事情来取得一些成功，但是这个让我摸不着头脑。我正在玩弄这段代码。我认为 Bryan Oakley 可能已经写了这个例子，但不是正面的。

基本上就是一个分页的例子。我添加了 buttoncontroloff 和 buttoncontrolon 函数来尝试控制菜单按钮的状态。我在第 1 页 class 中尝试过，但没有用。

class Page1(Page):
    def __init__(self, *args, **kwargs):
        tk.Frame.__init__(self, MainMenu, *args, **kwargs)
        newframe = tk.Frame(self, width=780, height=540, background="red")
        newframe.place(anchor="c", relx=.5, rely=.5)
        main = MainView()
        main.buttoncontrolon()

我在开始时确实禁用了其中一个按钮，所以我有一部分。但是当我试图在两个 class 之间执行此操作时，我无法弄清楚。当您单击第 2 页按钮时，我只想启用第 1 页按钮。

import Tkinter as tk
from Tkinter import *


class Page(tk.Frame):
    def __init__(self, *args, **kwargs):
        tk.Frame.__init__(self, *args, **kwargs)
    def show(self):
        self.lift()


class Page1(Page):
    def __init__(self, *args, **kwargs):
        tk.Frame.__init__(self, *args, **kwargs)
        newframe = tk.Frame(self, width=780, height=540, background="red")
        newframe.place(anchor="c", relx=.5, rely=.5)

class Page2(Page):
    def __init__(self, *args, **kwargs):
        tk.Frame.__init__(self, *args, **kwargs)
        newframe = tk.Frame(self, width=780, height=540, background="blue")
        newframe.place(anchor="c", relx=.5, rely=.5)


class MainView(tk.Frame):
    def __init__(self, *args, **kwargs):
        tk.Frame.__init__(self, *args, **kwargs)
        p1 = Page1(self)
        p2 = Page2(self)

        buttonframe = tk.Frame(self)
        container = tk.Frame(self)
        buttonframe.pack(side="top", fill="x", expand=False)
        container.pack(side="top", fill="both", expand=True)

        p1.place(in_=container, x=0, y=0, relwidth=1, relheight=1)
        p2.place(in_=container, x=0, y=0, relwidth=1, relheight=1)

        self.b1 = tk.Button(buttonframe, text="Page 1", command=lambda: p1.lift())
        self.b1.pack(side="left")
        self.b2 = tk.Button(buttonframe, text="Page 2", command=lambda: p2.lift())
        self.b2.pack(side="left")

        p1.show()

    def buttoncontroloff(self):
        self.b1.config(state = DISABLED)

    def buttoncontrolon(self):
        self.b1.config(state = NORMAL)

if __name__ == "__main__":
    root = tk.Tk()
    main = MainView(root)
    main.buttoncontroloff()
    main.pack(side="top", fill="both", expand=True)
    root.wm_geometry("800x600")
    root.mainloop()

Answer 1

我会这样做：在 MainView 中编写一个方法来打开编号页面 (0 ...):

def open_page(self, page_number):
    # enable all except the button for this page.
    for i, button in enumerate(self.buttons):
        if i == page_number:
            button.config(state=DISABLED)
        else:
            button.config(state=ACTIVE)

    self.pages[page_number].lift()

使按钮使用此方法传入页码，作为它们的命令：

self.b1 = tk.Button(buttonframe, 
    text="Page 1", command=lambda: self.open_page(0))
self.b2 = tk.Button(buttonframe, 
    text="Page 2", command=lambda: self.open_page(1))

然后将所有页面和按钮放入这些列表中：

p1 = Page1(self)
p2 = Page2(self)
self.pages = [ p1, p2 ]

和

self.buttons = [ self.b1, self.b2 ]

请记住，列表使用从 0 开始的索引。现在这以后很容易重构为 add_page 可以为页面创建一个按钮，并将两者都放入列表等

Page 不需要关心 Button 本身；这不是他们的责任范围，Button不属于他们。

Answer 2

Antti，我修正了错误。下面这段代码效果很好！我会将您的解决方案标记为已回答。再次感谢。

import Tkinter as tk
from Tkinter import *


class Page(tk.Frame):
    def __init__(self, *args, **kwargs):
        tk.Frame.__init__(self, *args, **kwargs)
    def show(self):
        self.lift()

class Page1(Page):
    def __init__(self, *args, **kwargs):
        tk.Frame.__init__(self, *args, **kwargs)
        newframe = tk.Frame(self, width=780, height=540, background="red")


class Page2(Page):
    def __init__(self, *args, **kwargs):
        tk.Frame.__init__(self, *args, **kwargs)
        newframe = tk.Frame(self, width=780, height=540, background="blue")
        newframe.place(anchor="c", relx=.5, rely=.5)


class MainView(tk.Frame):
    def __init__(self, *args, **kwargs):
        tk.Frame.__init__(self, *args, **kwargs)
        p1 = Page1(self)
        p2 = Page2(self)
        self.pages = [ p1, p2 ]

        buttonframe = tk.Frame(self)
        container = tk.Frame(self)
        buttonframe.pack(side="top", fill="x", expand=False)
        container.pack(side="top", fill="both", expand=True)

        p1.place(in_=container, x=0, y=0, relwidth=1, relheight=1)
        p2.place(in_=container, x=0, y=0, relwidth=1, relheight=1)

        self.b1 = tk.Button(buttonframe, text="Page 1", command=lambda: self.open_page(0))
        self.b2 = tk.Button(buttonframe, text="Page 2", command=lambda: self.open_page(1))
        self.b2.pack(side="left")
        self.b1.pack(side="left")
        self.buttons = [ self.b1, self.b2 ]

        p1.show()


    def open_page(self, page_number):
        # enable all except the button for this page.
        for i, button in enumerate(self.page_buttons):
            if i == page_number:
                button.config(state=DISABLED)
            else:
                button.config(state=ACTIVE)
        self.pages[page_number].lift()


if __name__ == "__main__":
    root = tk.Tk()
    main = MainView(root)
    #main.buttoncontroloff()
    main.pack(side="top", fill="both", expand=True)
    root.wm_geometry("800x600")
    root.mainloop()

仍在与 class 范围作斗争

Still struggling with class scope

python

scope

class