界面编程基础-计算器.py

from tkinter import *
master = Tk()

frame = Frame(master)
frame.pack(padx = 10,pady =10)
v1= StringVar()
v2 = StringVar()
v3 = StringVar()
def test(content):
    return content.isdigit()
testCMD = frame.register(test)
e1 = Entry(frame,textvariable=v1,validate = "key",\
           validatecommand = (testCMD,"%P")).grid(row = 0,\
                                                  column = 0)

Label(frame,text = "+").grid(row = 0,column = 1)
e2 = Entry(frame,textvariable=v2,validate = "focusout",\
           validatecommand = (testCMD,"%P")).grid(row = 0,\
                                                  column = 2)
Label(frame,text = "=").grid(row = 0,column = 3)

e3 = Entry(frame,textvariable = v3,state = "readonly").grid(row = 0,\
                                                             column = 4)
def calc():
    result = int(v1.get())+ int(v2.get())
    v3.set(str(result))
Button(frame,text = "计算结果",command = calc).grid(row = 1,column = 2,pady = 5)
mainloop()