Question

如何在tkinter中为标签设置新值？我有这个代码，但它只显示一个空白窗口对不起我的英语，如果可以的话，请解释一下。（我是编程新手）谢谢你的关注！

import os, time, tkinter, urllib
from tkinter import *
from urllib.request import *
from urllib.error import *

class App:
    def __init__(self, master):
        v = StringVar()
        start_time = time.time()
        frame = Frame(master)
        frame.pack()
        self.label = Label(frame, textvariable=v).pack()
        if self.internet_on() == 1:
            v.set = "Internet is online"
            start_time = time.time()
        else:
            v.set = "Internet is offline!  Downtime: " + str(time.time() - start_time)


    def internet_on(self):
        try:
            response=urllib.request.urlopen('http://www.google.com.br',timeout=1)
            return True
        except urllib.error.URLError as err: pass
        return False            
top = tkinter.Tk()
app = App(top)

top.mainloop()

Answer 1

v.set是一种方法，你不应该把它写成 -

v.set = "Internet is online"

你应该调用它并传递你想要写为参数的字符串 -

v.set("Internet is online")

和

v.set("Internet is offline!  Downtime: " + str(time.time() - start_time))

如评论中所述，您还可以直接设置标签的文本值，然后使用label.config()更改文本。示例 -

import os, time, tkinter, urllib
from tkinter import *
from urllib.request import *
from urllib.error import *

class App:
    def __init__(self, master):
        start_time = time.time()
        frame = Frame(master)
        frame.pack()
        if self.internet_on() == 1:
            self.label = Label(frame, text="Internet is online")
            self.label.pack()
            start_time = time.time()
        else:
            self.label = Label(frame, text="Internet is offline!  Downtime: " + str(time.time() - start_time))
            self.label.pack()


    def internet_on(self):
        try:
            response=urllib.request.urlopen('http://www.google.com.br',timeout=1)
            return True
        except urllib.error.URLError as err: pass
        return False            
top = tkinter.Tk()
app = App(top)

top.mainloop()

解决您的要求的最佳方式 -

在'internet_on'中，定期检查互联网状态（更改标签中的文字）。我已经尝试使用而没有成功。

使用.after()方法Tk()指定时间（以毫秒为单位）（可能大约5000毫秒左右，您可以决定这一点）并将iternet_on方法指定为第二个参数然后使用internet_on方法更新标签。示例 -

import os, time, tkinter, urllib
from tkinter import *
from urllib.request import *
from urllib.error import *

class App:
    def __init__(self, master):
        start_time = time.time()
        self.master = master
        self.frame = Frame(master)
        self.frame.pack()
        self.label = Label(self.frame, text="")
        self.label.pack()
        self.start_time = time.time()


    def internet_on(self):
        try:
            response=urllib.request.urlopen('http://www.google.com.br',timeout=1)
            self.label.config(text="Internet is online")
        except urllib.error.URLError as err:
            self.label.config(text="Internet is offline!  Downtime: " + str(time.time() - self.start_time))
        self.master.after(5000,self.internet_on)          
top = tkinter.Tk()
app = App(top)
top.after(5000,app.internet_on)
top.mainloop()

Answer 2

最简单的方法是在忘记返回布尔值并使用root.after的方法中进行更新：

from tkinter import *
import  urllib.request
import urllib.error

class App(Frame):
    def __init__(self, master):
        Frame.__init__(self, master)
        self.start_time = time.time()
        self.label = Label(root, text="Starting.....")
        self.label.pack()
        self.internet_on()

    def internet_on(self):
        try:
            urllib.request.urlopen('http://www.google.com.br', timeout=1)
            self.label.config(text="Internet is online")
            self.start_time = time.time()
        except urllib.error.URLError:
            self.label.config(text="Internet is offline!  Downtime: " + str(time.time() - self.start_time))
        root.after(1000, self.internet_on)

root = tkinter.Tk()
app = App(root)
app.pack()

Tkinter为标签设置了新值

2 个答案: