无法更改按钮颜色，因为未定义-Python .Tkinter

Question

尝试配置按钮，以便单击后更改颜色。

from tkinter import *

root = Tk()

def  buttonsMake():
    for c in range(10):
        for r in range(3):
            movieSeats=Button(root, text="Empty", bg="green", fg="white", 
width=5, height=1, command=lambda c=c, r=r:[redClick(c, r)])
            movieSeats.grid(row=r,column=c)


def redClick(c, r):
    movieSeats.configure(bg="red")



buttonsMake()
root.mainloop()

我希望它会改变颜色这是错误：

movieSeats=Button(root, text="Empty", bg="green", fg="white", width=5, 
height=1, command=lambda c=c, r=r:[redClick(c, r)])
  File "C:/Users/----/Downloads/test2.py", line 21, in redClick
    movieSeats.configure(bg="red")
NameError: name 'movieSeats' is not defined

Answer 1

movieSeats是局部变量buttonsMake()因此不存在在redClick ，你会得到错误name 'movieSeats' is not defined

您必须在buttonsMake()使用global movieSeats才能创建全局变量。

---

BTW：

您将所有按钮都关联到同一变量，因此您只能访问最后一个按钮。 您可以将所有按钮保留在列表中或将其发送给redClick作为参数

import tkinter as tk

# --- functions ---

def make_buttons():

    for c in range(10):
        for r in range(3):
            btn = tk.Button(root, text="Empty")
            btn['command'] = lambda c=c, r=r, b=btn:red_click(c, r, b)
            btn.grid(row=r,column=c)

def red_click(c, r, btn):
    btn.configure(bg="red")

# --- main ---

root = tk.Tk()

make_buttons()

root.mainloop()