Messagebox无法正常工作

Question

我的消息框的代码无法在我的窗口中运行。其他一切都有效，但是当我运行它时，我的“关于”消息框将不会显示。我想在我的窗口点击“关于”时弹出消息框。我能做些什么才能让它发挥作用？

from tkinter import *
from tkinter import messagebox
calculator = Tk()
calculator.title("Calculator")
calculator.geometry("317x145")

menubar = Menu(calculator)

class Calculator(Frame):
    def __init__(self):
        Frame.__init__(self)
        display = Frame(calculator, bd=0, width=1000, height=1000, relief=SUNKEN)
        buttons = Frame(calculator, bd=0, width=7, height=1, relief=GROOVE)
        display.grid(column=0, row=0, padx=0, pady=0)
        buttons.grid(column=0, row=1, padx=1)
        numbers = StringVar()
        self.results = Entry(display, textvariable=numbers, width=31, fg="DarkOrchid4", bg="lavender blush", font="Verdana")
        self.results.pack()
        self.results.grid(column=0, row=0)

        def showup(x):
            return lambda: self.results.insert(END, x)

        numbers=["7", "4", "1", "8", "5", "2", "9", "6", "3"]
        for i in range(9):
            n=numbers[i]
            Button(buttons, bg="snow", text=n, width=7, height=1, command=showup(n), relief=RAISED).grid(row=i%3, column=i//3)

        Clear = Button(buttons, bg="snow", text="C", width=7, height=1, command=self.clear, relief=RAISED)
        Clear.grid(padx=2, pady=2, column=3, row=0)
        Equals = Button(buttons, bg="snow", text="=", width=7, height=1, command=self.equals, relief=RAISED)
        Equals.grid(padx=2, pady=2, column=4, row=3)
        All_clear = Button(buttons, bg="snow", text="AC", width=7, height=1, command=self.all_clear, relief=RAISED)
        All_clear.grid(padx=2, pady=2, column=4, row=0)
        Bracket_one = Button(buttons, bg="snow", text="(", width=7, height=1, command=self.bracket_one, relief=RAISED)
        Bracket_one.grid(padx=2, pady=2, column=2, row=3)
        Bracket_two = Button(buttons, bg="snow", text=")", width=7, height=1, command=self.bracket_two, relief=RAISED)
        Bracket_two.grid(padx=2, pady=2, column=3, row=3)
        Zero = Button(buttons, bg="snow", text="0", width=7, height=1, command=self.zero, relief=RAISED)
        Zero.grid(padx=2, pady=2, column=0, row=3)
        Decimal_point = Button(buttons, bg="snow", text=".", width=7, height=1, command=self.decimal_point, relief=RAISED)
        Decimal_point.grid(padx=2, pady=2, column=1, row=3)
        Multiplication = Button(buttons, bg="red", text="x", width=7, height=1, command=self.multiplication, relief=RAISED)
        Multiplication.grid(padx=2, pady=2, column=3, row=1)
        Division = Button(buttons, bg="powder blue", text="/", width=7, height=1, command=self.division, relief=RAISED)
        Division.grid(padx=2, pady=2, column=4, row=1)
        Addition = Button(buttons, bg="yellow", text="+", width=7, height=1, command=self.addition, relief=RAISED)
        Addition.grid(padx=2, pady=2, column=3, row=2)
        Subtraction = Button(buttons, bg="green", text="-", width=7, height=1, command=self.subtraction, relief=RAISED)
        Subtraction.grid(padx=2, pady=2, column=4, row=2)

    def equals(self):
        try:
            result = eval(self.results.get())
        except:
            result = "Invalid input"
        self.all_clear()
        self.results.insert(0, result)
    def zero(self):
        self.results.insert(END, "0")
    def bracket_one(self):
        self.results.insert(END, "(")
    def bracket_two(self):
        self.results.insert(END, ")")
    def all_clear(self):
        self.results.delete(0, END)
    def clear(self):
        self.results.delete(-1)
    def multiplication(self):
        self.results.insert(END, "*")
    def division(self):
        self.results.insert(END, "/")
    def addition(self):
        self.results.insert(END, "+")
    def subtraction(self):
        self.results.insert(END, "-")
    def decimal_point(self):
        self.results.insert(END, ".")    

def about():
    messagebox.showinfo(title = "About", message = "Author")
    return
helpMenu = Menu(menubar)
menubar.add_command(label = "About", command=about)

if __name__ == '__main__':
    Calculator().mainloop()
    calculator.config(menu=menubar)
    calculator.mainloop()

Answer 1

您的问题是您没有将menubar与您的根应用程序相关联。这就是它永远不会出现的原因。您需要将应用程序的menu配置为您创建的menubar。示例 -

calculator.configure(menu=menubar)

此外，将代码移到框架中也会更好。示例 -

from tkinter import *
from tkinter import messagebox
calculator = Tk()
calculator.title("Calculator")
calculator.geometry("317x145")

menubar = Menu(calculator)

class Calculator(Frame):
    def __init__(self):
        Frame.__init__(self)
        display = Frame(calculator, bd=0, width=1000, height=1000, relief=SUNKEN)
        buttons = Frame(calculator, bd=0, width=7, height=1, relief=GROOVE)
        display.grid(column=0, row=0, padx=0, pady=0)
        buttons.grid(column=0, row=1, padx=1)
        numbers = StringVar()
        self.results = Entry(display, textvariable=numbers, width=31, fg="DarkOrchid4", bg="lavender blush", font="Verdana")
        self.results.pack()
        self.results.grid(column=0, row=0)

        def showup(x):
            return lambda: self.results.insert(END, x)

        numbers=["7", "4", "1", "8", "5", "2", "9", "6", "3"]
        for i in range(9):
            n=numbers[i]
            Button(buttons, bg="snow", text=n, width=7, height=1, command=showup(n), relief=RAISED).grid(row=i%3, column=i//3)

        Clear = Button(buttons, bg="snow", text="C", width=7, height=1, command=self.clear, relief=RAISED)
        Clear.grid(padx=2, pady=2, column=3, row=0)
        Equals = Button(buttons, bg="snow", text="=", width=7, height=1, command=self.equals, relief=RAISED)
        Equals.grid(padx=2, pady=2, column=4, row=3)
        All_clear = Button(buttons, bg="snow", text="AC", width=7, height=1, command=self.all_clear, relief=RAISED)
        All_clear.grid(padx=2, pady=2, column=4, row=0)
        Bracket_one = Button(buttons, bg="snow", text="(", width=7, height=1, command=self.bracket_one, relief=RAISED)
        Bracket_one.grid(padx=2, pady=2, column=2, row=3)
        Bracket_two = Button(buttons, bg="snow", text=")", width=7, height=1, command=self.bracket_two, relief=RAISED)
        Bracket_two.grid(padx=2, pady=2, column=3, row=3)
        Zero = Button(buttons, bg="snow", text="0", width=7, height=1, command=self.zero, relief=RAISED)
        Zero.grid(padx=2, pady=2, column=0, row=3)
        Decimal_point = Button(buttons, bg="snow", text=".", width=7, height=1, command=self.decimal_point, relief=RAISED)
        Decimal_point.grid(padx=2, pady=2, column=1, row=3)
        Multiplication = Button(buttons, bg="red", text="x", width=7, height=1, command=self.multiplication, relief=RAISED)
        Multiplication.grid(padx=2, pady=2, column=3, row=1)
        Division = Button(buttons, bg="powder blue", text="/", width=7, height=1, command=self.division, relief=RAISED)
        Division.grid(padx=2, pady=2, column=4, row=1)
        Addition = Button(buttons, bg="yellow", text="+", width=7, height=1, command=self.addition, relief=RAISED)
        Addition.grid(padx=2, pady=2, column=3, row=2)
        Subtraction = Button(buttons, bg="green", text="-", width=7, height=1, command=self.subtraction, relief=RAISED)
        Subtraction.grid(padx=2, pady=2, column=4, row=2)
        self.menubar = Menu(self)
        def about():
            messagebox.showinfo(title = "About", message = "Author")
            return
        self.helpMenu = Menu(self.menubar)
        self.menubar.add_cascade(label="Help",menu=self.helpMenu)
        self.helpMenu.add_command(label = "About", command=about)
        calculator.config(menu=self.menubar)

    def equals(self):
        try:
            result = eval(self.results.get())
        except:
            result = "Invalid input"
        self.all_clear()
        self.results.insert(0, result)
    def zero(self):
        self.results.insert(END, "0")
    def bracket_one(self):
        self.results.insert(END, "(")
    def bracket_two(self):
        self.results.insert(END, ")")
    def all_clear(self):
        self.results.delete(0, END)
    def clear(self):
        self.results.delete(-1)
    def multiplication(self):
        self.results.insert(END, "*")
    def division(self):
        self.results.insert(END, "/")
    def addition(self):
        self.results.insert(END, "+")
    def subtraction(self):
        self.results.insert(END, "-")
    def decimal_point(self):
        self.results.insert(END, ".")    


if __name__ == '__main__':
    Calculator().mainloop()
    calculator.config(menu=menubar)
    calculator.mainloop()