[SOLVED] wxpython + after changing panel and redo layout panel is very small

I change my panels by destroying panel 1 and then show panel 2. I cannot use the method creating both and hide en show, because than I have other problems. But after redo my layout my panel is very small. How can I make it the same size as before?

This is my testcode

import wx

class Main(wx.Frame):
def __init__(self, parent=None, id=-1, notify_channel="chanMicroanalysis", **kwargs):

    # general panel information
    wx.Frame.__init__(self, parent, wx.ID_ANY)
    self.SetTitle('Microanalysis')
    self.backpanel = wx.Panel(self, wx.ID_ANY)

    # first panel
    self.Choicepanel = wx.Panel(self.backpanel, wx.ID_ANY)

    self.lblChoose = wx.StaticText(self.Choicepanel, label="Choose:")
    self.btnChooseFilterOnly = wx.Button(self.Choicepanel, wx.ID_ANY, "Filter only ")
    self.btnChooseMA = wx.Button(self.Choicepanel, wx.ID_ANY, "Microanalyse")
    self.btnChooseCellInfo = wx.Button(self.Choicepanel, wx.ID_ANY, " CellInfo ")
    self.btnChooseReport = wx.Button(self.Choicepanel, wx.ID_ANY, "Report")

    # second panel: cellinfo
    self.test1 =wx.Panel(self.backpanel, wx.ID_ANY)
    self.Cellinfopanel = self.test1

    self.lblChooseingo = wx.StaticText(self.Cellinfopanel, label="Choose:")
    self.btnChooseFilter = wx.Button(self.Cellinfopanel, wx.ID_ANY, "Filter only ")
    self.btnChooseprr = wx.Button(self.Cellinfopanel, wx.ID_ANY, "Microanalyse")
    self.btnChooseCell = wx.Button(self.Cellinfopanel, wx.ID_ANY, " CellInfo ")
    self.btnChoose = wx.Button(self.Cellinfopanel, wx.ID_ANY, "Report")


    self._do_layout()
    self._do_bindings()

def _do_layout(self):
    self.h_main_sizer = wx.BoxSizer()
    self.h_centerbuttonsizer = wx.BoxSizer()
    self.h_centerbutton1sizer = wx.BoxSizer()
    self.v_firstsizer = wx.BoxSizer(wx.VERTICAL)

    self.v_secondsizer = wx.BoxSizer(wx.VERTICAL)
    self.v_thirdsizer = wx.BoxSizer(wx.VERTICAL)
    self.v_fourthsizer = wx.BoxSizer(wx.VERTICAL)
    self.v_buttonsizer = wx.BoxSizer(wx.VERTICAL)
    self.v_button1sizer = wx.BoxSizer(wx.VERTICAL)
    ########################################"
    self.v_firstsizer.Add(self.Choicepanel, 1, wx.EXPAND)
    self.v_buttonsizer.Add(self.lblChoose, 0, wx.CENTER)
    self.v_buttonsizer.Add(self.btnChooseFilterOnly, 0, wx.EXPAND)
    self.v_buttonsizer.Add(self.btnChooseMA, 0, wx.EXPAND)
    self.v_buttonsizer.Add(self.btnChooseCellInfo, 0, wx.EXPAND)
    self.v_buttonsizer.Add(self.btnChooseReport, 0, wx.EXPAND)

    self.h_centerbuttonsizer.AddStretchSpacer(1)
    self.h_centerbuttonsizer.Add(self.v_buttonsizer, 0, wx.CENTER)
    self.h_centerbuttonsizer.AddStretchSpacer(1)

    self.Choicepanel.SetSizer(self.h_centerbuttonsizer)
    self.h_centerbuttonsizer.Fit(self.Choicepanel)
        ########################################"
    self.v_secondsizer.Add(self.Cellinfopanel, 5, wx.EXPAND)
    self.v_button1sizer.Add(self.lblChooseingo, 0, wx.CENTER)
    self.v_button1sizer.Add(self.btnChooseFilter, 0, wx.EXPAND)
    self.v_button1sizer.Add(self.btnChooseprr, 0, wx.EXPAND)
    self.v_button1sizer.Add(self.btnChooseCell, 0, wx.EXPAND)
    self.v_button1sizer.Add(self.btnChoose, 0, wx.EXPAND)

    self.h_centerbutton1sizer.AddStretchSpacer(1)
    self.h_centerbutton1sizer.Add(self.v_button1sizer, 0, wx.CENTER)
    self.h_centerbutton1sizer.AddStretchSpacer(1)

    self.Cellinfopanel.SetSizer(self.h_centerbutton1sizer)
    self.h_centerbutton1sizer.Fit(self.Choicepanel)
    ########################################"


    self.h_main_sizer.Add(self.v_firstsizer, 20, wx.EXPAND)
    self.h_main_sizer.Add(self.v_secondsizer, 20, wx.EXPAND)

    self.backpanel.SetSizer(self.h_main_sizer)
    self.h_main_sizer.Fit(self)
    #
    # self.Choicepanel.Show()
    # self.Cellinfopanel.Hide()
    # self.MApanel.Hide()
    # self.Reportpanel.Hide()
    self.Choicepanel.Show()
    self.Cellinfopanel.Show()
    self.statusMAPanelShown = False


def _do_bindings(self):

    self.btnChooseprr.Bind(wx.EVT_BUTTON, self.on_chooseMA)


def on_chooseMA(self, event):
    print "in choose MA"
    self.showMAPanel()
    self._do_layout()

    #
    # self.Layout()


def showMAPanel(self):
    print "in showmapanel"
    self.test1.Destroy()
    self.test2 =wx.Panel(self.backpanel, wx.ID_ANY)
    self.Cellinfopanel = self.test2
    self.lblChooseingo = wx.StaticText(self.Cellinfopanel, label="test:")
    self.btnChooseFilter = wx.Button(self.Cellinfopanel, wx.ID_ANY, "test1 ")
    self.btnChooseprr = wx.Button(self.Cellinfopanel, wx.ID_ANY, "test2")
    self.btnChooseCell = wx.Button(self.Cellinfopanel, wx.ID_ANY, " test3 ")
    self.btnChoose = wx.Button(self.Cellinfopanel, wx.ID_ANY, "test4")

if __name__ == '__main__':
app = wx.PySimpleApp()
MAview = Main(None, wx.ID_ANY)
MAview.Maximize()
MAview.Show()
app.MainLoop()

EDIT: This is not the same question as is proposed. In the proposed question, I used the hide and show method, and there was also a resizing problem, but there the panel was to big. I actually solved the other question and I will add the answer.