Tkinter-Python 3.3-销毁窗口的问题

Question

我目前正在用tkinter编写一个基本程序，并且对一个特定的窗口 （称为“ appetiser ”）有问题。

前一个屏幕上的按钮。

我真的对自己遇到的问题感到困惑，所以我在下面粘贴了整个appetiser窗口。 （对不起，只是将其丢到这里）

#Appetiser Window
def appetiser():
    global app, root


#----------------------------------MEAL-1------------------------
#----------------------------------MEAL-1------------------------
    def PlusMix():
        global MixQuan
        MixQuan = MixQuan + 1
        DisplayButton["text"]=str(MixQuan)

    def NegMix():
        global MixQuan
        MixQuan = MixQuan - 1
        DisplayButton["text"]=str(MixQuan)

    Label(app, text = "", width = 65, height = 5).grid(row = 1, column = 0, sticky = N)

    Label(app,text = "Mixed Starter", font = ("roboto", 20)).grid(row = 2, column = 1, sticky = W)

    DisplayButton = Button(app, text = MixQuan, bg="magenta")
    DisplayButton.grid(column = 3, row = 2, sticky = W)
    DisplayButton.config(height = 10, width = 10 )

    Plus1Button = Button(app, text = "+1", command=PlusMix, bg="magenta")
    Plus1Button.grid(column = 4, row = 2, sticky = W)
    Plus1Button.config(height = 10, width = 10 )

    Neg1Button = Button(app, text = "-1", command=NegMix, bg="magenta")
    Neg1Button.grid(column = 2, row = 2, sticky = W)
    Neg1Button.config(height = 10, width = 10 )
#----------------------------------MEAL-2-------------------------
#----------------------------------MEAL-2-------------------------

    def PlusDuck():
        global DuckQuan
        DuckQuan = DuckQuan + 1 
        Display2Button["text"]=str(DuckQuan)

    def NegDuck():
        global DuckQuan
        DuckQuan = DuckQuan - 1 
        Display2Button["text"]=str(DuckQuan)



    Label(app,text = "Crispy Duck", font = ("roboto", 20)).grid(row = 3, column = 1, sticky = W)


    Display2Button = Button(app, text = DuckQuan, bg="magenta")
    Display2Button.grid(column = 3, row = 3, sticky = W)
    Display2Button.config(height = 10, width = 10 )

    Plus2Button = Button(app, text = "+1", command=PlusDuck, bg="magenta")
    Plus2Button.grid(column = 4, row = 3, sticky = W)
    Plus2Button.config(height = 10, width = 10 )

    Neg2Button = Button(app, text = "-1", command=NegDuck, bg="magenta")
    Neg2Button.grid(column = 2, row = 3, sticky = W)
    Neg2Button.config(height = 10, width = 10 )

#----------------------------------MEAL-3---------------------------
#----------------------------------MEAL-3---------------------------

    def plus3():
        global LambQuan
        LambQuan = LambQuan + 1 
        Display3Button["text"]=str(LambQuan)

    def neg3():
        global LambQuan
        LambQuan = LambQuan - 1 
        Display3Button["text"]=str(LambQuan)

    Label(app,text = "Lamb starter", font = ("roboto", 20)).grid(row = 4, column = 1, sticky = W)

    Display3Button = Button(app, text = LambQuan, bg="magenta")
    Display3Button.grid(column = 3, row = 4, sticky = W)
    Display3Button.config(height = 10, width = 10 )

    Plus3Button = Button(app, text = "+1", command=plus3, bg="magenta")
    Plus3Button.grid(column = 4, row = 4, sticky = W)
    Plus3Button.config(height = 10, width = 10 )

    Neg3Button = Button(app, text = "-1", command=neg3, bg="magenta")
    Neg3Button.grid(column = 2, row = 4, sticky = W)
    Neg3Button.config(height = 10, width = 10 )

#----------------------------------------------------
#----------------------------------------------------

    BackButton = Button(app, text = "Back", command=OpenMain, bg="magenta")
    BackButton.grid(column = 2, row = 5, sticky = W)
    BackButton.config(height = 10, width = 10 )


    FinishButton = Button(app, text = "Finish", command=OpenFinish, bg="magenta")
    FinishButton.grid(column = 4, row = 5, sticky = W)
    FinishButton.config(height = 10, width = 10 )


    app = Frame(root)
    app.grid()

    Label(app, text = "", width = 75, height = 20).grid(row = 1, column = 0, sticky = N)

    root.mainloop()

现在

从其他窗口调用了2个函数OpenMain()和OpenWindow()以返回到先前的屏幕，但是在其他窗口中调用它们时，它们可以正常工作。

我只有从“ [ FinishButton ] ”和“ [ BackButton ] ”从此窗口调用函数时遇到问题。

以下是先前已调用且可以正常运行的两个函数。

#Wipe window and open main
def OpenMain():
    global app, root
    app.destroy()
    app = Frame(root) 
    app.grid()
    main()

#Wipe appetiser window and draw finish window
def OpenFinish():   
    global app, root
    app.destroy()
    app = Frame(root) 
    app.grid()
    FinishWindow()

当OpenFinish()函数被调用时，“ appetiser ” 窗口 ，不被破坏，并直接下创建的主窗口 appetiser 窗口 。

就像我说的那样，对不起，我只是将代码转储到这里，但是我无法弄清楚问题所在。

这些功能在其他窗口中也能正常工作，并且我遵循了相同的格式来为程序的其余部分创建窗口。

任何帮助将非常感激！

Answer 1

1. 避免global -s
2. 设计在对象- /基于类的方式
3. 撰写对象＆ 管理他们的对准及严格控制的基于TKinter-hiearachy内其内容.Tk() / .Toplevel() / .Frame()容器”
4. 避免自我毁灭性的练习，以使.Button()有权通过.destroy() +对self赋值来self

---

#  <appetiser> is not a window, it is a procedure ( a segment of code )
#
def appetiser():
    global app, root
    ...
    BackButton   = Button( app,
                           text    = "Back",
                           command = OpenMain,             # --> app.destroy()-->
                           bg      = "magenta"
                           )
    ...
    FinishButton = Button( app,
                           text    = "Finish",
                           command = OpenFinish,           # --> app.destroy()-->
                           bg      = "magenta"
                           )
    ...
# -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- |
#                                                                               v
def OpenMain():
    global app, root
    app.destroy()                                          # <-- COMMIT SUICCIDE
    app = Frame( root )                                    # new Frame instance
    app.grid()
    ...

def OpenFinish():   
    global app, root
    app.destroy()                                          # <-- COMMIT SUICCIDE
    app = Frame( root )                                    # new Frame instance
    ...