ShowModal之后，wxPython对话框冻结

Question

直接在这里的代码，值得一千个单词来解释它。

#!/usr/bin/env python2

import wx

class TestDialog(wx.Dialog):

    def __init__self(*arg, **args):

        wx.Dialog.__init__(self, parent, id, title, size=(350,300))

        sizer = self.CreateTextSizer('My Buttons')

        # bad()

        sizer = wx.BoxSizer(wx.VERTICAL)

        sizer.Add(wx.Button(self, -1, 'Button'), 0, wx.ALL, 5)

        sizer.Add(wx.Button(self, -1, 'Button'), 0, wx.ALL, 5)

        sizer.Add(wx.Button(self, -1, 'Button'), 0, wx.ALL, 5)

        sizer.Add(wx.Button(self, -1, 'Button'), 0, wx.ALL|wx.ALIGN_CENTER, 5)

        sizer.Add(wx.Button(self, -1, 'Button'), 0, wx.ALL|wx.EXPAND, 5)

        sizer.Fit(self)

        self.SetSizer(sizer)

    def InitUI(self):

        pnl = wx.Panel(self)

        vbox = wx.BoxSizer(wx.VERTICAL)

        btn = wx.Button(pnl, label='Ok')

        vbox.Add(btn, 1, flag=wx.LEFT)

        pnl.SetSizer(vbox)

    def OnClose(self):

        self.Destroy()

class MyFrame(wx.Frame):

    def __init__(self, parent, id, title):

        wx.Frame.__init__(self, parent, id, title, size=(550,500))

        panel = wx.Panel(self, -1)

        wx.Button(panel, 1, 'Show Custom Dialog', (100,100))

        self.Bind (wx.EVT_BUTTON, self.OnShowCustomDialog)

    def OnShowCustomDialog(self, event):

        dia = TestDialog(self, -1, 'buttons')

        dia.ShowModal()

        # dia.Destroy()

if __name__ == "__main__":

    try:

        app = wx.App()

        frame = MyFrame(None, wx.ID_ANY, 'dialog')

        frame.Show()

        # import wx.lib.inspection

        # wx.lib.inspection.InspectionTool().Show()

        app.MainLoop()

    except:

        import sys

        import traceback

        xc = traceback.format_exception(*sys.exc_info())

        wx.MessageBox(''.join(xc))

显示了主窗口，但显示对话框后似乎什么也没有执行。即使取消注释，bad()呼叫似乎也不会显示任何内容。