WxPython, popup menus, callbacks and Windows XP

My goal: the user clicks a button. From the button pops up a two-level menu. The user clicks on something, and this triggers a callback which does stuff.

Here is a minimal example:

import wx

class MyApp(wx.App):
    def OnInit(self):
        frame = TestFrame(None, -1, "Hello from wxPython")
        frame.Show(True)
        self.SetTopWindow(frame)
        re开发者_开发技巧turn True

class TestFrame(wx.Frame):
    def __init__(self, *args, **kw):
        wx.Frame.__init__(self, *args, **kw)

        sizer = wx.BoxSizer()
        button = wx.Button(self, label='Click me')
        sizer.Add(button)
        self.SetSizerAndFit(sizer)

        mainmenu = wx.Menu()
        next_id = 1000000
        submenus = {}

        for title in ['Submenu 1', 'Submenu 2', 'Submenu 3']:
            mit = wx.MenuItem(mainmenu, id=next_id, text=title)
            submenu = wx.Menu()
            mit.SetSubMenu(submenu)
            mainmenu.AppendItem(mit)

            next_id = next_id + 1
            submenus[title] = submenu

        items = [('Submenu 1', 'foo'),
                 ('Submenu 1', 'bar'),
                 ('Submenu 2', 'one'),
                 ('Submenu 2', 'two'),
                 ('Submenu 2', 'three'),
                 ('Submenu 3', 'zif'),
                 ('Submenu 3', 'zaf')]

        for title, item in items:
            submenu = submenus[title]
            mit = wx.MenuItem(submenu, id=next_id, text=item)
            submenu.AppendItem(mit)
            next_id = next_id + 1

            def callback(e, title=title, item=item):
                print 'Item clicked: %s, %s' % (title, item)

            self.Bind(wx.EVT_MENU, callback, mit)


        def show(e):
            self.PopupMenu(mainmenu, button.GetPosition())
        button.Bind(wx.EVT_BUTTON, show)

app = MyApp(0)
app.MainLoop()

Also:

Python 2.5.1 (r251:54863, Apr 18 2007, 08:51:08) [MSC v.1310 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import wx
>>> wx.version()
'2.8.10.1 (msw-unicode)'

You are handling ID generation yourself and in doing that mixing up IDs, anyway you do not need to generate IDs yourself use wx.NewId(), if you replace next_id with that it will work e.g.

mit = wx.MenuItem(submenu, id=wx.NewId(), text=item)