Question

我被要求编辑我的代码，所以我决定包含整个计算器脚本

from tkinter import *
global choice 
choice = 0


#Program
def calculate(*event):
    if choice == 1:
        try:
            add1 = ccalc1.get()
            add2 = ccalc2.get()
        except:
            no = Label(app, text="You must use a number").grid(row=0, column=0)
        answ = add1 + add2         
        answer = Label(app, text = answ).grid(row=1, column=0)
    elif choice == 2:
        try:
            sub1 = ccalc1.get()
            sub2 = ccalc2.get()
        except:
            no = Label(app, text="You must use a number").grid(row=1, column=0)
        answ = sub1 - sub2         
        answer = Label(app, text = answ).grid(row=1, column=0) 
def choice2():
    global choice
    choice = 2       
#End Program
#GUI
#Window Info
calc = Tk()
calc.title("Calculator")
calc.geometry("200x140")
#End Window Info

#Build Window
app = Frame(calc)
app.grid()
ccalc1 = IntVar()
ccalc2 = IntVar()

#Widgets
if choice == 0:
    welcome = Label(app, text="Select a choice")
elif choice == 2:
    welcome.config(text="Subtraction")
calcbox1 = Entry(app,textvariable=ccalc1)
calcbox2 = Entry(app,textvariable=ccalc2)
submit = Button(app, text="CALCULATE", command = calculate)

welcome.grid(row=0,column=0)
calcbox1.grid(row=2, column=0)
calcbox2.grid(row=3, column=0)
submit.grid(row=4, column=0)
calc.bind('<Return>', calculate)
#End Widgets

#Menu
menu=Menu(calc)
#Operations
filemenu = Menu(menu,tearoff=0)
filemenu.add_command(label="Subtract", command = choice2)  
menu.add_cascade(label="Operations",menu=filemenu)     
calc.config(menu=menu)
calc.mainloop()
#End GUI

欢迎标签文字不会相应改变是错误的。

更新：我收录了整个计算器代码

感谢任何帮助。

Answer 1

很难理解你期望发生的事情。例如，看看这段代码：

#Widgets
if choice == 0:
    welcome = Label(app, text="Select a choice")
elif choice == 2:
    welcome.config(text="Subtraction")

此代码只会执行一次，并且选择将始终为零，因为这是您初始化它的内容。它执行一次因为它不在函数中而不在循环中，所以当python解析代码时它将运行它并移动到下一行。该文本块将永远不会再次处理。

如果您希望在用户选择菜单项时更改标签，则需要在choice2函数中执行该代码：

def choice2():
    global choice
    choice = 2
    welcome.config(text="Subtraction")

tkinter：如何更改程序内部的标签

1 个答案: