python - 为什么 wxGridSizer 在 wxDialog 上的初始化比在 wxFrame 上的初始化慢得多？

Question

这似乎是windows特有的，这里有一个重现效果的例子:

import wx


def makegrid(window):
    grid = wx.GridSizer(24, 10, 1, 1)
    window.SetSizer(grid)
    for i in xrange(240):
        cell = wx.Panel(window)
        cell.SetBackgroundColour(wx.Color(i, i, i))
        grid.Add(cell, flag=wx.EXPAND)


class TestFrame(wx.Frame):
    def __init__(self, parent):
        wx.Frame.__init__(self, parent)
        makegrid(self)


class TestDialog(wx.Dialog):
    def __init__(self, parent):
        wx.Dialog.__init__(self, parent)
        makegrid(self)


class Test(wx.Frame):
    def __init__(self):
        wx.Frame.__init__(self, None)
        btn1 = wx.Button(self, label="Show Frame")
        btn2 = wx.Button(self, label="Show Dialog")
        sizer = wx.BoxSizer(wx.VERTICAL)
        self.SetSizer(sizer)
        sizer.Add(btn1, flag=wx.EXPAND)
        sizer.Add(btn2, flag=wx.EXPAND)
        btn1.Bind(wx.EVT_BUTTON, self.OnShowFrame)
        btn2.Bind(wx.EVT_BUTTON, self.OnShowDialog)

    def OnShowFrame(self, event):
        TestFrame(self).Show()

    def OnShowDialog(self, event):
        TestDialog(self).ShowModal()


app = wx.PySimpleApp()
app.TopWindow = Test()
app.TopWindow.Show()
app.MainLoop()

我已经在以下配置上尝试过:

• 带有 Python 2.5.4 和 wxPython 2.8.10.1 的 Windows 7
• 带有 Python 2.5.2 和 wxPython 2.8.7.1 的 Windows XP
• 带有 Python 2.6.0 和 wxPython 2.8.9.1 的 Windows XP
• Ubuntu 9.04 与 Python 2.6.2 和 wxPython 2.8.9.1

wxDialog 不仅在 Ubuntu 上很慢。

Answer 1

我在 wxPython-users mailing list 上收到了回复，可以通过在显示对话框之前显式调用 Layout 来解决此问题。

This is really weird...

My guess is that this is due to Windows and wxWidgets not dealing very well with overlapping siblings, and so when the sizer is doing the initial layout and moving all the panels from (0,0) to where they need to be that something about the dialog is causing all of them to be refreshed and repainted at each move. If you instead do the initial layout before the dialog is shown then it is just as fast as the frame.

You can do this by adding a call to window.Layout() at the end of makegrid.

-- Robin Dunn