Python Тема не слушает флаг

Question

Я использую слегка отредактированный пример из здесь . Кнопка запуска в GUI запускает поток, кнопка остановки останавливает его. Я добавил x = x + 1 и печать (x) к l oop, это тоже работает. Но если я попытаюсь довести x до GUI, кнопка остановки перестает работать. Я не понимаю почему. Можете ли вы объяснить это мне?

Код ниже. Такой запуск даст вам результат после остановки потока. Раскомментирующая строка 48 будет давать вам результат каждую 1 секунду, но кнопка остановки перестанет работать.

import time
from threading import *
import wx

# Button definitions
ID_START = wx.NewId()
ID_STOP = wx.NewId()

# Define notification event for thread completion
EVT_RESULT_ID = wx.NewId()

def EVT_RESULT(win, func):
    """Define Result Event."""
    win.Connect(-1, -1, EVT_RESULT_ID, func)

class ResultEvent(wx.PyEvent):
    """Simple event to carry arbitrary result data."""
    def __init__(self, data):
        """Init Result Event."""
        wx.PyEvent.__init__(self)
        self.SetEventType(EVT_RESULT_ID)
        self.data = data
        pass

# Thread class that executes processing
class WorkerThread(Thread):
    """Worker Thread Class."""
    def __init__(self, notify_window):
        """Init Worker Thread Class."""
        Thread.__init__(self)
        self._notify_window = notify_window
        self._want_abort = 0
        # This starts the thread running on creation, but you could
        # also make the GUI thread responsible for calling this
        self.start()

    def run(self):
        """Run Worker Thread."""
        # This is the code executing in the new thread. Simulation of
        # a long process (well, 10s here) as a simple loop - you will
        # need to structure your processing so that you periodically
        # peek at the abort variable
        x=0
        for i in range(10):
            x = x + 1
            time.sleep(1)
            print(x)
            #wx.PostEvent(self._notify_window, ResultEvent(x))
            if self._want_abort:
                # Use a result of None to acknowledge the abort (of
                # course you can use whatever you'd like or even
                # a separate event type)
                wx.PostEvent(self._notify_window, ResultEvent('ended with ' + str(x)))
                return
        # Here's where the result would be returned (this is an
        # example fixed result of the number 10, but it could be
        # any Python object)
        wx.PostEvent(self._notify_window, ResultEvent(10))

    def abort(self):
        """abort worker thread."""
        # Method for use by main thread to signal an abort
        self._want_abort = 1

# GUI Frame class that spins off the worker thread
class MainFrame(wx.Frame):
    """Class MainFrame."""
    def __init__(self, parent, id):
        """Create the MainFrame."""
        wx.Frame.__init__(self, parent, id, 'Thread Test')

        # Dumb sample frame with two buttons
        wx.Button(self, ID_START, 'Start', pos=(0,0))
        wx.Button(self, ID_STOP, 'Stop', pos=(0,50))
        self.status = wx.StaticText(self, -1, '', pos=(0,100))

        self.Bind(wx.EVT_BUTTON, self.OnStart, id=ID_START)
        self.Bind(wx.EVT_BUTTON, self.OnStop, id=ID_STOP)

        # Set up event handler for any worker thread results
        EVT_RESULT(self,self.OnResult)

        # And indicate we don't have a worker thread yet
        self.worker = None

    def OnStart(self, event):
        """Start Computation."""
        # Trigger the worker thread unless it's already busy
        if not self.worker:
            self.status.SetLabel('Starting computation')
            self.worker = WorkerThread(self)

    def OnStop(self, event):
        """Stop Computation."""
        # Flag the worker thread to stop if running
        if self.worker:
            self.status.SetLabel('Trying to abort computation')
            self.worker.abort()

    def OnResult(self, event):
        """Show Result status."""
        if event.data is None:
            # Thread aborted (using our convention of None return)
            self.status.SetLabel('Computation aborted')
        else:
            # Process results here
            self.status.SetLabel('Computation Result: %s' % event.data)
        # In either event, the worker is done
        self.worker = None

class MainApp(wx.App):
    """Class Main App."""
    def OnInit(self):
        """Init Main App."""
        self.frame = MainFrame(None, -1)
        self.frame.Show(True)
        self.SetTopWindow(self.frame)
        return True

if __name__ == '__main__':
    app = MainApp(0)
    app.MainLoop()

Answer 1

Вы нашли пример classi c, но теперь он очень устарел. Либо ищите современный пример, либо выберите кости из следующего:

import time
import wx
from threading import Thread

import wx.lib.newevent
progress_event, EVT_PROGRESS_EVENT = wx.lib.newevent.NewEvent()

class ThreadFrame(wx.Frame):

    def __init__(self, title, parent=None):
        wx.Frame.__init__(self, parent=parent, title=title)
        panel = wx.Panel(self)
        self.btn = wx.Button(panel,label='Stop Long running process', size=(200,30), pos=(10,10))
        self.btn.Bind(wx.EVT_BUTTON, self.OnExit)
        self.progress = wx.Gauge(panel,size=(240,10), pos=(10,50), range=240)

        #Bind to the progress event issued by the thread
        self.Bind(EVT_PROGRESS_EVENT, self.OnProgress)
        #Bind to Exit on frame close
        self.Bind(wx.EVT_CLOSE, self.OnExit)
        self.Show()

        self.mythread = TestThread(self)
        #Enable the GUI to be responsive by briefly returning control to the main App
        while self.mythread.isAlive():
            time.sleep(0.1)
            wx.GetApp().Yield()
            continue

        try:
            self.OnExit(None)
        except:
            pass

    def OnProgress(self, event):
        self.progress.SetValue(event.count)
        #or for indeterminate progress
        #self.progress.Pulse()

    def OnExit(self, event):
        if self.mythread.isAlive():
            self.mythread.terminate() # Shutdown the thread
            self.mythread.join() # Wait for it to finish
        self.Destroy()

class TestThread(Thread):
    def __init__(self,parent_target):
        Thread.__init__(self)
        self.parent = parent_target
        self.stopthread = False
        self.time = time.time()
        self.start()    # start the thread

    def run(self):
        # A loop that will run for 2 minutes then terminate
        while self.stopthread == False:
            curr_loop = int(time.time() - self.time)
            if curr_loop < 240:
                time.sleep(0.1)
                evt = progress_event(count=curr_loop)
                #Send back current count for the progress bar
                try:
                    wx.PostEvent(self.parent, evt)
                except: # The parent frame has probably been destroyed
                    self.terminate()
            else:
                self.terminate()

    def terminate(self):
        self.stopthread = True

class MyPanel(wx.Panel):

    def __init__(self, parent):
        wx.Panel.__init__(self, parent)
        self.text_count = 0
        self.thread_count = 0
        self.parent=parent
        btn = wx.Button(self, wx.ID_ANY, label='Start Long running process', size=(200,30), pos=(10,10))
        btn.Bind(wx.EVT_BUTTON, self.Thread_Frame)
        btn2 = wx.Button(self, wx.ID_ANY, label='Is the GUI still active?', size=(200,30), pos=(10,50))
        btn2.Bind(wx.EVT_BUTTON, self.AddText)
        self.txt = wx.TextCtrl(self, wx.ID_ANY, style= wx.TE_MULTILINE, pos=(10,90),size=(400,100))

    def Thread_Frame(self, event):
        self.thread_count += 1
        frame = ThreadFrame(title='Threaded Task '+str(self.thread_count), parent=self.parent)

    def AddText(self,event):
        self.text_count += 1
        txt = "Gui is still active " + str(self.text_count)+"\n"
        self.txt.write(txt)

class MainFrame(wx.Frame):

    def __init__(self):
        wx.Frame.__init__(self, None, title='Main Frame', size=(600,400))
        panel = MyPanel(self)
        self.Show()


if __name__ == '__main__':
    app = wx.App(False)
    frame = MainFrame()
    app.MainLoop()