是否可以在 tkinter 中更新标签？

Question

我编写了一个可以求平方根的程序，但我注意到在找到 3 和 4 的平方根时，它并没有更改标签，而是在旧标签之上创建了一个新标签（请参阅图片）。 这就是我的代码的样子：

import tkinter as tk

root= tk.Tk()

canvas1 = tk.Canvas(root, width = 400, height = 300)
canvas1.pack()

entry1 = tk.Entry (root) 
canvas1.create_window(200, 140, window=entry1)

def getSquareRoot ():  
    x1 = entry1.get()
    
    label1 = tk.Label(root, text= float(x1)**0.5)
    canvas1.create_window(200, 230, window=label1)
    
button1 = tk.Button(text='Get the Square Root', command=getSquareRoot)
canvas1.create_window(200, 180, window=button1)

root.mainloop()

This is what it looks like

Answer 1

您应该只有 1 个标签，您应该使用结果更新，因为它像这样进来：

import tkinter as tk

root= tk.Tk()

canvas1 = tk.Canvas(root, width = 400, height = 300)
canvas1.pack()

entry1 = tk.Entry (root) 
canvas1.create_window(200, 140, window=entry1)

# Create the results label
results_label = tk.Label(root)
canvas1.create_window(200, 230, window=results_label)

def getSquareRoot():
    x1 = entry1.get()
    # Update the label with the new result:
    results_label.config(text=float(x1)**0.5)
    
button1 = tk.Button(text='Get the Square Root', command=getSquareRoot)
canvas1.create_window(200, 180, window=button1)

root.mainloop()