如何在 python 中设置 Tkinter 以显示和更新变量？

Question

我试图每 2.5 秒更新一次变量，但不知何故它不会显示在 Tkinter 上。

我编写了除了 Tkinter 相关内容之外的所有代码，因为我在该领域知之甚少。我操纵了从网站获得的代码，该网站提供了使用 Tkinter 的示例。

代码如下：

import threading
from tkinter import *

def onclick():
   pass


its1_c = 0    # first upgrade amount
its2_c = 0    # second upgrade amount
ITS1 = its1_c * 30 # amount of first upgrade owned x multiplier to money
ITS2 = its2_c * 70 # amount of second upgrade owned x multiplier to money

cashflow = 0
balance = 100
def moneygain():
    global cashflow
    global balance
    global text
    text = balance
    cashflow = balance
    threading.Timer(2.5, moneygain).start()
    cashflow = cashflow + 10
    cashflow = cashflow + ITS2
    cashflow = cashflow + ITS1
    balance = cashflow
    print("Balance: " + str(balance))
    text.insert(INSERT, balance)
    root = Tk()
    text = Text(root)
    text.insert(INSERT, balance)
    text.pack()

    text.tag_add("here", "1.0", "1.4")
    text.tag_add("start", "1.8", "1.13")
    text.tag_config("here", background="yellow", foreground="blue")
    text.tag_config("start", background="black", foreground="green")
    root.mainloop()  

moneygain()

当我尝试显示“余额”时，它不会更新。相反，它抛出了这个错误：

Exception in thread Thread-2:
Traceback (most recent call last):

File "D:\Python34\lib\threading.py", line 911, in _bootstrap_inner
    self.run()
  File "D:\Python34\lib\threading.py", line 1177, in run
    self.function(*self.args, **self.kwargs)
  File "D:/Python34/menugui.py", line 27, in moneygain
    text.insert(INSERT, balance)
AttributeError: 'int' object has no attribute 'insert'

如何在 Tkinter 窗口上显示balance？

Answer 1

为了解决您在 tkinter 上更新 balance 变量的问题，这是我的解决方案：

  from Tkinter import *

  root = Tk()
  moneyShown = Label(root, font=('times', 20, 'bold')) #use a Label widget, not Text
  moneyShown.pack(fill=BOTH, expand=1)
  def onclick():
     pass


  its1_c = 0    # first upgrade amount
  its2_c = 0    # second upgrade amount
  ITS1 = its1_c * 30 # amount of first upgrade owned x multiplier to money
  ITS2 = its2_c * 70 # amount of second upgrade owned x multiplier to money

  cashflow = 0
  balance = 100
  def moneygain():
      global cashflow
      global balance
      global text
      text = balance
      cashflow = balance

      cashflow = cashflow + 10
      cashflow = cashflow + ITS2
      cashflow = cashflow + ITS1
      balance = cashflow
      print("Balance: " + str(balance))

      moneyShown.configure(text="Balance: "+str(balance)) #changes the label's text
      moneyShown.after(2500, moneygain) #tkinter's threading (look more into how this works)
  moneygain()
  root.mainloop()

Tkinter 真的不喜欢老式的线程，使用 .after() 的最后一行 moneygain() 的函数效果更好

此外，我还发挥了创造性，将您的 Text 小部件切换为 Label。正如您所说您是该语言的新手，我很确定在这种情况下Label 比Text 更合适（至少对于这个问题修复！）。

另一个建议：当您要多次调用一个函数（因为我们多次调用moneygain）时，最好不要在这些函数中创建小部件。当我测试你的代码时，它会无限地创建新的 Text 小部件，因为它被一遍又一遍地调用（同样，可能不是你想要的）。

Tkinter 一开始很难学，但是一旦你学会了，它真的很有趣！祝你的项目好运！