如果在wxPython中使用了ScrolledPanel，如何正确添加另一个面板？

Question

在我的 wxPython 4.1.0 继承自 wx.Frame，然后从 wx.Panel，增加一个 ScrolledPanel 除此之外，我还要加上一个 wx.Bitmap 作为子代。该位图图像的高度大于滚动面板的高度，所以垂直滚动条被显示出来--一切都符合预期。

然后我又添加了一个 wx.Panel 下方的滚动面板，没有任何子菜单，但仅此一项就使滚动面板中的滚动条消失了。这是一个bug还是一个功能？

下面是一个完全可行的例子。取消在 def init_panel(self) 来查看奇怪的行为。

import wx
import wx.grid
import wx.lib.intctrl
import wx.lib.scrolledpanel

class TestApp(wx.Frame):
    IMAGE_SIZE = 800
    SCROLL_SPEED = 10

    def __init__(self):
        super(TestApp, self).__init__(
            None, title="wxPython Test", style=wx.DEFAULT_FRAME_STYLE ^ wx.RESIZE_BORDER,
        )

        self.init_panel()
        self.main_panel.Layout()
        self.main_panel.Fit()
        self.Center()
        self.Show()

    def init_panel(self):
        self.main_panel = wx.Panel(self)
        self.main_sizer = wx.BoxSizer(wx.VERTICAL)
        self.main_panel.SetSizer(self.main_sizer)

        self.bitmaps_panel = wx.lib.scrolledpanel.ScrolledPanel(self.main_panel)
        self.bitmaps_panel.SetMinSize((-1, 250))
        self.bitmaps_panel.SetupScrolling(scroll_x=False, scroll_y=True, rate_y=self.SCROLL_SPEED)
        self.bitmaps_panel.SetAutoLayout(True)

        self.bitmaps_sizer = wx.BoxSizer(wx.VERTICAL)
        self.bitmaps_panel.SetSizer(self.bitmaps_sizer)

        bitmap = wx.Bitmap(wx.Image(self.IMAGE_SIZE, self.IMAGE_SIZE))
        self.bitmaps_sizer.Add(wx.StaticBitmap(self.bitmaps_panel, wx.ID_ANY, bitmap))
        self.bitmaps_sizer.Fit(self)
        self.main_sizer.Add(self.bitmaps_panel, 0, flag=wx.EXPAND)

        ## With this block commented it works, uncomment to see the scroll bar dissapear
        # self.stats_panel = wx.Panel(self)
        # self.stats_sizer = wx.BoxSizer(wx.VERTICAL)
        # self.stats_panel.SetSizer(self.stats_sizer)
        # self.main_sizer.Add(self.stats_panel, 0, flag=wx.EXPAND)

        self.main_sizer.Fit(self)

if __name__ == "__main__":
    wxapp = wx.App()
    app = TestApp()
    wxapp.MainLoop()

Answer 1

这个怪异的现象是不是可以通过您创建的 "滚动面板 "来解释。stats_panel 吾辈 self而不是 self.main_panel?

import wx
import wx.grid
import wx.lib.intctrl
import wx.lib.scrolledpanel

class TestApp(wx.Frame):
    IMAGE_SIZE = 800
    SCROLL_SPEED = 10

    def __init__(self):
        super(TestApp, self).__init__(
            None, title="wxPython Test", style=wx.DEFAULT_FRAME_STYLE)

        self.init_panel()
        self.main_panel.Layout()
        self.main_panel.Fit()
        self.Center()
        self.Show()

    def init_panel(self):
        self.main_panel = wx.Panel(self)

        self.bitmaps_panel = wx.lib.scrolledpanel.ScrolledPanel(self.main_panel)
        self.bitmaps_panel.SetMinSize((-1, 250))
        self.bitmaps_panel.SetupScrolling(scroll_x=True, scroll_y=True, rate_y=self.SCROLL_SPEED)
        self.bitmaps_panel.SetAutoLayout(True)

        bitmap = wx.Bitmap(wx.Image(2000, self.IMAGE_SIZE))
        self.bitmap = wx.StaticBitmap(self.bitmaps_panel, wx.ID_ANY, bitmap)

        self.stats_panel = wx.Panel(self.main_panel)
        self.stats_panel.SetBackgroundColour('lightblue')
        label = wx.StaticText(self.stats_panel, label="Stats Panel")


        self.bitmaps_sizer = wx.BoxSizer(wx.VERTICAL)
        self.bitmaps_sizer.Add(self.bitmap, 0, wx.EXPAND, 5)
        self.bitmaps_panel.SetSizer(self.bitmaps_sizer)

        self.stats_sizer = wx.BoxSizer(wx.VERTICAL)
        self.stats_sizer.Add(label)
        self.stats_panel.SetSizer(self.stats_sizer)

        self.main_sizer = wx.BoxSizer(wx.VERTICAL)
        self.main_sizer.Add(self.bitmaps_panel, 0, flag=wx.EXPAND)
        self.main_sizer.Add(self.stats_panel, 1, flag=wx.EXPAND)
        self.main_panel.SetSizer(self.main_sizer)


if __name__ == "__main__":
    wxapp = wx.App()
    app = TestApp()
    wxapp.MainLoop()