wxPython 进度条崩溃并且无法按预期工作

Question

我正在尝试使用 wx.Gauge 实现一个简单的进度条。在转到我的原始代码之前，我想编写如下小脚本：

import time
for i in range(101):
    print i
    time.sleep(0.5)

上面的脚本只是延迟了 for 循环。现在，该程序的相同概念是挂起我的 Ubuntu 12.04LTS 并最终显示完整的进度条。代码如下：

# -*- coding: utf-8 -*- 
import wx
import time

class MainFrame ( wx.Frame ):

    def __init__( self, parent ):
        wx.Frame.__init__ ( self, parent, id = wx.ID_ANY, title = u"Progress Bar Example", pos = wx.DefaultPosition, size = wx.Size( 460,135 ), style = wx.CAPTION|wx.CLOSE_BOX|wx.TAB_TRAVERSAL )

        self.SetSizeHintsSz( wx.DefaultSize, wx.DefaultSize )

        bSizer2 = wx.BoxSizer( wx.VERTICAL )

        self.progress = wx.Gauge( self, wx.ID_ANY, 100, wx.Point( 10,10 ), wx.Size( 400,-1 ), wx.GA_HORIZONTAL|wx.GA_SMOOTH )
        self.progress.SetValue( 0 ) 
        self.progress.SetForegroundColour( wx.Colour( 255, 255, 255 ) )

        bSizer2.Add( self.progress, 0, wx.ALL, 5 )

        self.start_again = wx.Button( self, wx.ID_ANY, u"START", wx.DefaultPosition, wx.DefaultSize, 0 )
        bSizer2.Add( self.start_again, 0, wx.ALL, 5 )


        self.SetSizer( bSizer2 )
        self.Layout()

        self.Centre( wx.BOTH )

        # Connect Events
        self.start_again.Bind( wx.EVT_BUTTON, self.run_progreee_bar )

    def __del__( self ):
        pass


    # Virtual event handlers, overide them in your derived class
    def run_progreee_bar( self, event ):
        self.progress.SetValue( 0 )
        for i in range(101):
            self.progress.SetValue( i )
            self.delay()
    def delay(self):
        time.sleep(0.5)

app  = wx.App()
frame = MainFrame(None)
frame.Show()
app.MainLoop()

我相信这个程序在语法上是正确的。我也觉得逻辑是对的。我在这段代码中有什么问题？

Answer 1

发生这种情况的原因是您的计数器的增长速度超过了 app.MainLoop() 重绘进度条的速度。因此，如果您在按下开始后尝试与您的小部件交互，它会挂起，直到循环结束并显示最终状态。您需要在 GUI 编程中使用线程来执行这些任务。我稍微改变了你的代码。现在应该可以正常工作了。

import wx, time, thread

class MainFrame ( wx.Frame ):

    def __init__( self, parent ):
        wx.Frame.__init__ ( self, parent, id = wx.ID_ANY, title = u"Progress Bar Example", pos = wx.DefaultPosition, size = wx.Size( 460,135 ), style = wx.CAPTION|wx.CLOSE_BOX|wx.TAB_TRAVERSAL )

        self.SetSizeHintsSz( wx.DefaultSize, wx.DefaultSize )

        bSizer2 = wx.BoxSizer( wx.VERTICAL )

        self.progress = wx.Gauge( self, wx.ID_ANY, 100, wx.Point( 10,10 ), wx.Size( 400,-1 ), wx.GA_HORIZONTAL|wx.GA_SMOOTH )
        self.progress.SetValue( 0 ) 
        self.progress.SetForegroundColour( wx.Colour( 255, 255, 255 ) )

        bSizer2.Add( self.progress, 0, wx.ALL, 5 )

        self.start_again = wx.Button( self, wx.ID_ANY, u"START", wx.DefaultPosition, wx.DefaultSize, 0 )
        bSizer2.Add( self.start_again, 0, wx.ALL, 5 )


        self.SetSizer( bSizer2 )
        self.Layout()

        self.Centre( wx.BOTH )

        # Connect Events
        self.start_again.Bind( wx.EVT_BUTTON, self.run_progreee_bar)

    def __del__( self ):
        pass


    # Virtual event handlers, overide them in your derived class
    def run_progreee_bar( self, event ):
        thread.start_new_thread(self.update_progress_bar, ())

    def update_progress_bar(self):
        self.start_again.Disable()
        self.progress.SetValue( 0 )
        for i in range(101):
            self.progress.SetValue( i )
            self.delay()
        self.start_again.Enable()

    def delay(self):
        time.sleep(0.5)

app  = wx.App()
frame = MainFrame(None)
frame.Show()
app.MainLoop()

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