線程和tkinter python 3

Question

我聽說Python中的線程不容易處理，他們變得更加糾結於tkinter。

我有以下問題。我有兩個類，一個用於GUI，另一個用於無限過程。首先，我啓動GUI類，然後啓動無限過程的類。我希望當你關閉GUI時，它也完成了無限的過程，程序結束。

代碼的簡化版本如下：

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() 

當我點擊關閉按鈕（在右上角）出現在控制檯以下錯誤：

Tcl_AsyncDelete ：異步處理程序由錯誤的線程刪除

我不知道它爲什麼發生或它的意思，請幫助！

Answer 1

All Tcl commands need to originate from the same thread。由於tkinter的 依賴於Tcl，通常必須使所有tkinter gui語句來自同一個線程。因爲 mainWindow在tkinterGui線程中被實例化，但是 - 因爲mainWindow是tkinterGui的屬性 - 直到tkinterGui在主線程中被銷燬才被銷燬。即改變self.mainWindow到mainWindow -

該問題可以通過不使mainWindow的tkinterGui 的屬性來避免。當run方法在tkinterGui線程中結束時，這允許mainWindow被銷燬。但是，往往就可以避免線程完全使用mainWindow.after調用來代替：

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() 

---

如果要定義一個類裏面的圖形用戶界面，你還可以這樣做：

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() 

甚至更簡單，只需使用主線程來運行GUI主循環：

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

此處的修復很簡單，但很難發現：

呼叫mainWindow.quit()後立即mainwindow.mainloop()，使清理髮生在同一個線程創建了TK UI，而不是主線程時蟒蛇退出上一個上。