Python GUI 应用中 Pango 错误

用户在运行一个 Python GUI 应用时，遇到了 Pango 错误，该错误通常出现在程序运行一分钟后。以下是该用户提供的代码片段：

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# generated by wxGlade 0.6.3 on Fri Jul  9 17:00:08 2010

import wx
import settimer

# begin wxGlade: extracode
# end wxGlade

class MyFrame(wx.Frame):
    def __init__(self, *args, **kwds):
        # begin wxGlade: MyFrame.__init__
        kwds["style"] = wx.DEFAULT_FRAME_STYLE
        wx.Frame.__init__(self, *args, **kwds)
        self.todo1 = wx.TextCtrl(self, -1, "")
        self.timer_label1 = wx.StaticText(self, -1, "00:00")
        self.set_timer1 = wx.Button(self, -1, "Set Timer")
        self.todo2 = wx.TextCtrl(self, -1, "")
        self.timer_label2 = wx.StaticText(self, -1, "00:00")
        self.set_timer2 = wx.Button(self, -1, "Set Timer")
        self.todo3 = wx.TextCtrl(self, -1, "")
        self.timer_label3 = wx.StaticText(self, -1, "00:00")
        self.set_timer3 = wx.Button(self, -1, "Set Timer")
        self.todo4 = wx.TextCtrl(self, -1, "")
        self.timer_label4 = wx.StaticText(self, -1, "00:00")
        self.set_timer4 = wx.Button(self, -1, "Set Timer")
        self.todo5 = wx.TextCtrl(self, -1, "")
        self.timer_label5 = wx.StaticText(self, -1, "00:00")
        self.set_timer5 = wx.Button(self, -1, "Set Timer")
        self.hours = 0
        self.minutes = 0

2、解决方案

该错误通常是由多线程问题引起的，解决方法是将计时器线程与 GUI 线程分开，让计时器线程独立运行。以下是修改后的代码片段：

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# generated by wxGlade 0.6.3 on Fri Jul  9 17:00:08 2010

import wx
import settimer
from threading import Thread

class MyFrame(wx.Frame):
    def __init__(self, *args, **kwds):
        # begin wxGlade: MyFrame.__init__
        kwds["style"] = wx.DEFAULT_FRAME_STYLE
        wx.Frame.__init__(self, *args, **kwds)
        self.todo1 = wx.TextCtrl(self, -1, "")
        self.timer_label1 = wx.StaticText(self, -1, "00:00")
        self.set_timer1 = wx.Button(self, -1, "Set Timer")
        self.todo2 = wx.TextCtrl(self, -1, "")
        self.timer_label2 = wx.StaticText(self, -1, "00:00")
        self.set_timer2 = wx.Button(self, -1, "Set Timer")
        self.todo3 = wx.TextCtrl(self, -1, "")
        self.timer_label3 = wx.StaticText(self, -1, "00:00")
        self.set_timer3 = wx.Button(self, -1, "Set Timer")
        self.todo4 = wx.TextCtrl(self, -1, "")
        self.timer_label4 = wx.StaticText(self, -1, "00:00")
        self.set_timer4 = wx.Button(self, -1, "Set Timer")
        self.todo5 = wx.TextCtrl(self, -1, "")
        self.timer_label5 = wx.StaticText(self, -1, "00:00")
        self.set_timer5 = wx.Button(self, -1, "Set Timer")
        self.hours = 0
        self.minutes = 0

        self.__set_properties()
        self.__do_layout()

        self.Bind(wx.EVT_BUTTON, self.on_set1, self.set_timer1)
        self.Bind(wx.EVT_BUTTON, self.on_set2, self.set_timer2)
        self.Bind(wx.EVT_BUTTON, self.on_set3, self.set_timer3)
        self.Bind(wx.EVT_BUTTON, self.on_set4, self.set_timer4)
        self.Bind(wx.EVT_BUTTON, self.on_set5, self.set_timer5)

    def on_set1(self, event): # wxGlade: MyFrame.<event_handler>
        self.timer_thread = TimerThread(self, self.minutes)
        self.timer_thread.start()
        event.Skip()

    def set_label(self):
        self.timer_label1.SetLabel("%02d:%02d" % (self.hours, self.minutes))
        self.minutes -= 1

class TimerThread(Thread):
    def __init__(self, track, minutes):
        Thread.__init__(self)
        self.track = track
        self.minutes = minutes

    def run(self):
        for sec in range(self.minutes):
            time.sleep(60)
            self.track.set_label()


# end of class MyFrame

if __name__ == "__main__":
    app = wx.PySimpleApp(0)
    wx.InitAllImageHandlers()
    main_frame = MyFrame(None, -1, "")
    app.SetTopWindow(main_frame)
    main_frame.Show()
    app.MainLoop()

在修改后的代码中，计时器线程被移出了 GUI 类，并作为单独的线程运行。这样，计时器线程就不会与 GUI 线程冲突，Pango 错误也不会再出现了。