线程和tkinter python 3

Question

我听说Python中的线程不容易处理，他们变得更加纠结于tkinter。

我有以下问题。我有两个类，一个用于GUI，另一个用于无限过程。首先，我启动GUI类，然后启动无限过程的类。我希望当你关闭GUI时，它也完成了无限的过程，程序结束。

代码的简化版本如下：

import time, threading 
from tkinter import * 
from tkinter import messagebox 

finish = False 

class tkinterGUI(threading.Thread): 
    def __init__(self): 
     threading.Thread.__init__(self) 

    def run(self): 
     global finish 
     #Main Window 
     self.mainWindow = Tk() 
     self.mainWindow.geometry("200x200") 
     self.mainWindow.title("My GUI Title") 
     #Label 
     lbCommand = Label(self.mainWindow, text="Hello world", font=("Courier New", 16)).place(x=20, y=20) 
     #Start 
     self.mainWindow.mainloop() 
     #When the GUI is closed we set finish to "True" 
     finish = True 

class InfiniteProcess(threading.Thread): 
    def __init__(self): 
     threading.Thread.__init__(self) 

    def run(self): 
     global finish 
     while not finish: 
      print("Infinite Loop") 
      time.sleep(3) 

GUI = tkinterGUI() 
GUI.start() 
Process = InfiniteProcess() 
Process.start() 

当我点击关闭按钮（在右上角）出现在控制台以下错误：

Tcl_AsyncDelete ：异步处理程序由错误的线程删除

我不知道它为什么发生或它的意思，请帮助！

Answer 1

All Tcl commands need to originate from the same thread。由于tkinter的 依赖于Tcl，通常必须使所有tkinter gui语句来自同一个线程。因为 mainWindow在tkinterGui线程中被实例化，但是 - 因为mainWindow是tkinterGui的属性 - 直到tkinterGui在主线程中被销毁才被销毁。即改变self.mainWindow到mainWindow -

该问题可以通过不使mainWindow的tkinterGui 的属性来避免。当run方法在tkinterGui线程中结束时，这允许mainWindow被销毁。但是，往往就可以避免线程完全使用mainWindow.after调用来代替：

import time, threading 
from tkinter import * 
from tkinter import messagebox 

def infinite_process(): 
    print("Infinite Loop") 
    mainWindow.after(3000, infinite_process) 


mainWindow = Tk() 
mainWindow.geometry("200x200") 
mainWindow.title("My GUI Title") 
lbCommand = Label(mainWindow, text="Hello world", font=("Courier New", 16)).place(x=20, y=20) 
mainWindow.after(3000, infinite_process) 
mainWindow.mainloop() 

---

如果要定义一个类里面的图形用户界面，你还可以这样做：

import time, threading 
from tkinter import * 
from tkinter import messagebox 

class App(object): 
    def __init__(self, master): 
     master.geometry("200x200") 
     master.title("My GUI Title") 
     lbCommand = Label(master, text="Hello world", 
          font=("Courier New", 16)).place(x=20, y=20) 

def tkinterGui(): 
    global finish 
    mainWindow = Tk() 
    app = App(mainWindow) 
    mainWindow.mainloop() 
    #When the GUI is closed we set finish to "True" 
    finish = True 

def InfiniteProcess(): 
    while not finish: 
     print("Infinite Loop") 
     time.sleep(3) 

finish = False 
GUI = threading.Thread(target=tkinterGui) 
GUI.start() 
Process = threading.Thread(target=InfiniteProcess) 
Process.start() 
GUI.join() 
Process.join() 

甚至更简单，只需使用主线程来运行GUI主循环：

import time, threading 
from tkinter import * 
from tkinter import messagebox 

class App(object): 
    def __init__(self, master): 
     master.geometry("200x200") 
     master.title("My GUI Title") 
     lbCommand = Label(master, text="Hello world", 
          font=("Courier New", 16)).place(x=20, y=20) 

def InfiniteProcess(): 
    while not finish: 
     print("Infinite Loop") 
     time.sleep(3) 

finish = False 
Process = threading.Thread(target=InfiniteProcess) 
Process.start() 

mainWindow = Tk() 
app = App(mainWindow) 
mainWindow.mainloop() 
#When the GUI is closed we set finish to "True" 
finish = True 
Process.join() 

Answer 2

此处的修复很简单，但很难发现：

呼叫mainWindow.quit()后立即mainwindow.mainloop()，使清理发生在同一个线程创建了TK UI，而不是主线程时蟒蛇退出上一个上。