import tkinter as tk

# 创建主窗口

root = tk.Tk()

root.title("云黑课堂例子——简单计算机")

# 输入框

entry = tk.Entry(root, width=16, font=('Arial', 24), borderwidth=2)

entry.grid(row=0, column=0, columnspan=4)

# 按钮点击事件

def button_click(number):

    current = entry.get()

    entry.delete(0, tk.END)

    entry.insert(0, current + str(number))

def button_clear():

    entry.delete(0, tk.END)

def button_equal():

    try:

        result = eval(entry.get())

        entry.delete(0, tk.END)

        entry.insert(0, result)

    except Exception as e:

        entry.delete(0, tk.END)

        entry.insert(0, "错误")

# 创建按钮

buttons = [

    '7', '8', '9', '/',

    '4', '5', '6', '*',

    '1', '2', '3', '-',

    '0', 'C', '=', '+'

]

row_val = 1

col_val = 0

for button in buttons:

    if button == 'C':

        btn = tk.Button(root, text=button, padx=20, pady=20, command=button_clear)

    elif button == '=':

        btn = tk.Button(root, text=button, padx=20, pady=20, command=button_equal)

    else:

        btn = tk.Button(root, text=button, padx=20, pady=20, command=lambda b=button: button_click(b))

    btn.grid(row=row_val, column=col_val)

    col_val += 1

    if col_val > 3:

        col_val = 0

        row_val += 1

# 启动主循环

root.mainloop()