如何更改線程中的變量？

Question

這是我的情況。比方說，我想創建一個線程，不斷打印數字1.當單擊一個按鈕時，值應該變爲2.我的問題是，我不確定如何在已經運行的線程中更改變量。這裏是我的代碼：

import wx 
from threading import Thread 
import time 

class testThread(Thread): 
    def __init__(self, parent): 
     self.parent = parent 
     Thread.__init__(self) 
     self.start() 

    def run(self): 
     while 1: 
      x = 1 
      print x 
      time.sleep(1) 

class testGUI(wx.Frame): 
    def __init__(self): 
     wx.Frame.__init__(self, None, -1, "Test", size=(500,270)) 
     panel = wx.Panel(self, -1) 

     self.buttonStart = wx.Button(panel, -1, label="Start thread", pos=(0,0)) 
     self.buttonChange = wx.Button(panel, -1, label="Change var", pos=(0,30)) 
     panel.Bind(wx.EVT_BUTTON, self.startThread, id=self.buttonStart.GetId()) 
     panel.Bind(wx.EVT_BUTTON, self.changeVar, id=self.buttonChange.GetId()) 

    def startThread(self, event): 
     testThread(self) 

    def changeVar(self, event): 
     # DO SOMETHING HERE THAT CHANGES 'x' IN THREAD TO 2... 
     pass 

if __name__ == '__main__': 
    app = wx.App(redirect=False) 
    frame = testGUI() 
    frame.Show(True) 
    app.MainLoop() 

所以，問題是，我該怎麼放在功能changeVar將修改變量x是在正在運行的線程的內容是什麼？提前致謝！

Answer 1

您不能更改局部變量。

你可以做的是這樣的：

class testThread(Thread): 
    def __init__(self, parent): 
     self.parent = parent 
     Thread.__init__(self) 
     self.start() 

    def run(self): 
     self.value = 1 
     while 1: 
      print self.value 
      time.sleep(1) 

class testGUI(wx.Frame): 
    def __init__(self): 
     wx.Frame.__init__(self, None, -1, "Test", size=(500,270)) 
     panel = wx.Panel(self, -1) 

     self.buttonStart = wx.Button(panel, -1, label="Start thread", pos=(0,0)) 
     self.buttonChange = wx.Button(panel, -1, label="Change var", pos=(0,30)) 
     panel.Bind(wx.EVT_BUTTON, self.startThread, id=self.buttonStart.GetId()) 
     panel.Bind(wx.EVT_BUTTON, self.changeVar, id=self.buttonChange.GetId()) 

    def startThread(self, event): 
     self.the_thread = testThread(self) 

    def changeVar(self, event): 
     # DO SOMETHING HERE THAT CHANGES 'x' IN THREAD TO 2... 
     self.the_thread.value = 2 

if __name__ == '__main__': 
    app = wx.App(redirect=False) 
    frame = testGUI() 
    frame.Show(True) 
    app.MainLoop() 

Answer 2

你不需要爲主題，在所有。 wx包含一個wx.Timer，它允許你在同一個線程中以一定的時間間隔調用你的函數。機會是，wx包括一個功能，可以做你想做的事情：

import wx 

class testGUI(wx.Frame): 
    def __init__(self): 
     wx.Frame.__init__(self, None, -1, "Test", size=(500,270)) 
     panel = wx.Panel(self, -1) 
     self.buttonStart = wx.Button(panel, -1, label="Start timer", pos=(0,0)) 
     self.buttonChange = wx.Button(panel, -1, label="Change var", pos=(0,30)) 
     panel.Bind(wx.EVT_BUTTON, self.startTimer, id=self.buttonStart.GetId()) 
     panel.Bind(wx.EVT_BUTTON, self.changeVar, id=self.buttonChange.GetId()) 
     self.value = 1 
     self.timer = wx.Timer(self) 
     self.Bind(wx.EVT_TIMER, self.printer, self.timer) 

    def startTimer(self, event): 
     self.timer.Start(1000) # 1 second 

    def printer(self, event): 
     print self.value 

    def changeVar(self, event): 
     self.value = 2 

if __name__ == '__main__': 
    app = wx.App(redirect=False) 
    frame = testGUI() 
    frame.Show(True) 
    app.MainLoop()