如何更新 tkinter label

Question

所以我正在尝试制作某种基本的自动答题器，其排名会在一定数量的点击后更新，但每当我更新排名时，应该显示的 label 不会改变，我不知道如何进行 label 更新

from tkinter import *

count = 0
rank = "click the button to rank up!"

window = Tk()

if count == 1:
    rank = "wow first click!"

def click():
    global count
    count += 1
    counter = Label(window, text=count).grid(row = 0, column = 1)

clicker = Button(window, text="The Button", padx = 50, pady = 50, command = click).grid(row = 0, column = 0)

rankDisplay = Label(window, text = rank, padx = 100, pady = 25).grid(row = 1, column = 0)
  
window.mainloop()

第一次点击后，排名仍然显示为“点击按钮排名”而不是“哇第一次点击”，这就是问题所在

Answer 1

这是代码：

from tkinter import *

count = 0

window = Tk()
def changed(text):
    rankDisplay.config(text=text)
    rankDisplay.grid(row = 1, column = 0)
def click():
    global count
    count += 1
    counter = Label(window, text=count).grid(row = 0, column = 1)
    if count == 1:
        changed("wow first click!")
    return count
clicker = Button(window, text="The Button", padx = 50, pady = 50, command = click).grid(row = 0, column = 0)
rankDisplay = Label(window, text = "", padx = 100, pady = 25)
changed("click the button to rank up!")
  
window.mainloop()

当您单击按钮时，label 文本将“单击按钮排名”更新为“哇第一次点击”。因为 label 的文本是一个 StringVar()，如果我设置 stringvar，则 label 的文本将更新为 stringvar

Answer 2

我已经知道这个问题了。 要解决这个问题，您必须为您的 label 创建一个全局变量：

global l1
l1 = Label(...)

然后，要修改文本，您必须在函数中执行以下操作：

l1.config(text=str(count))

Answer 3

看到这里你应该使用名为rankDisplay的 label 的update方法

这是代码：

from tkinter import *

count = 0



window = Tk()

rank = StringVar()
rank.set("Click the button to rank up")


def click():
    global count
    count += 1
    counter = Label(window, text=count).grid(row=0, column=1)
    if count == 1:
        rank.set("wow first click!")
        rankDisplay.update()


clicker = Button(window, text="The Button", padx=50, pady=50, command=click).grid(row=0, column=0)

rankDisplay = Label(window, textvariable=rank, padx=100, pady=25)
rankDisplay.grid(row=1, column=0)

window.mainloop()

代码中的修改：您应该知道tkinter中StringVar的概念才能使用update方法..链接了解它https://www.pythontutorial.net/tkinter/tkinter-stringvar/#:~:text=The%20Tkinter %20StringVar%20helps%20you,Label%20or%20Entry%20more%20effectively.&text=The%20StringVar%20constructor%20accepts%20three,defaults%20to%20the%20root%20window 。

在rankDisplay label 你必须使用textvariable属性而不是text

只有这些是变化......

Answer 4

刚刚在第 16 行添加了rankDisplay.configure(...) 。

代码：

from tkinter import *

count = 0
rank = "click the button to rank up!"

window = Tk()

#if count == 1:
    #rank = "wow first click!"

def click():
    global count
    count += 1
    counter = Label(window, text=count)
    counter.grid(row = 0, column = 1)
    rankDisplay.configure(text="wow first click!")

clicker = Button(window, text="The Button", padx = 50, pady = 50, command = click).grid(row = 0, column = 0)

rankDisplay = Label(window, text = rank, padx = 100, pady = 25)
rankDisplay.grid(row = 1, column = 0)
  
window.mainloop()

Output：

点击后Output：