wxpython's treectrl can't expand in windows
<p>Why my wxpython's treectrl can't show and expand in windows but ok in mac:</p>

<pre><code>import wx
class MyFrame(wx.Frame):
    def __init__(self, parent, id, title):
        wx.Frame.__init__(self, parent, id, title, wx.DefaultPosition, wx.Size(450, 350))
        hbox = wx.BoxSizer(wx.HORIZONTAL)
        vbox = wx.BoxSizer(wx.VERTICAL)
        panel1 = wx.Panel(self, -1)
        panel2 = wx.Panel(self, -1)
        self.tree = wx.TreeCtrl(panel1, 1, wx.DefaultPosition, (-1,-1), wx.TR_HIDE_ROOT|wx.TR_HAS_BUTTONS)
        root = self.tree.AddRoot('Programmer')
        os = self.tree.AppendItem(root, 'Operating Systems')
        self.tree.AppendItem(os, 'Linux')
        self.tree.AppendItem(os, 'FreeBSD')
        self.tree.AppendItem(os, 'OpenBSD')
        self.tree.AppendItem(os, 'NetBSD')
        self.tree.AppendItem(os, 'Solaris')
        self.tree.Bind(wx.EVT_TREE_SEL_CHANGED, self.OnSelChanged, id=1)
        self.display = wx.StaticText(panel2, -1, '',(10,10), style=wx.ALIGN_CENTRE)
        self.tree.Bind(wx.EVT_TREE_ITEM_EXPANDING,self.OnExpanding, id=1)
        self.tree.Bind(wx.EVT_TREE_ITEM_EXPANDED,self.OnExpanded, id=1)
        self.tree.Bind(wx.EVT_TREE_ITEM_ACTIVATED,self.OnActivated, id=1)
        self.tree.Bind(wx.EVT_TREE_ITEM_COLLAPSED,self.OnCollapsed, id=1)
        self.tree.Bind(wx.EVT_TREE_ITEM_COLLAPSING,self.OnCollaping, id=1)
        vbox.Add(self.tree, 1, wx.EXPAND)
        hbox.Add(panel1, 1, wx.EXPAND)
        hbox.Add(panel2, 1, wx.EXPAND)
        panel1.SetSizer(vbox)
        self.SetSizer(hbox)
        self.Centre()
    def OnSelChanged(self, event):
        item =  event.GetItem()
        self.display.SetLabel(self.tree.GetItemText(item))

    def OnExpanding(self,evt):
        print "OnExpanding"

    def OnExpanded(self,evt):
        print "OnExpaned"

    def OnActivated(self,evt):
        print "OnActivated"

    def OnCollapsed(self,evn):
        print "OnCollapsed"
    def OnCollaping(self,evt):
        print "OnCollaping"

class MyApp(wx.App):
    def OnInit(self):
        frame = MyFrame(None, -1, 'treectrl.py')
        frame.Show(True)
        self.SetTopWindow(frame)
        return True

app = MyApp(0)
app.MainLoop()
</code></pre>

<p><a href="https://i.stack.imgur.com/F7DwX.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/F7DwX.png" alt="inwindows it looks like this"></a></p>

<p><a href="https://i.stack.imgur.com/p4G93.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/p4G93.png" alt="on mac is ok"></a></p>

<p>I run this code with:
python2.7-win32 
wxPython3.0-win32-3.0.2.0-py27
window7-64</p>

<p>and in windows then event about expand and collaps is never be sended too</p>

<p>so how can tell me where am i wrong?</p>