wxpython 为什么小弟我的textctrl不能充满整个panel，现在显示的很窄

wxpython 为什么我的textctrl不能充满整个panel，现在显示的很窄


       def __init__(self):
        wx.Frame.__init__(self,None,-1,"快速启动",size=(650,520))
        panel=wx.Panel(self,-1)
        
        cmd=wx.StaticText(panel,-1,"cmd:")
        self.stringtext=wx.TextCtrl(panel,-1," ",size=(500,-1))
        self.button = wx.Button(panel,-1,label='Run',size=(60,30))
        self.button.Enable(False)
        self.Bind(wx.EVT_TEXT,self.OnEnter,self.stringtext) 
        self.Bind(wx.EVT_BUTTON,self.OpenFile,self.button)     

        head = wx.FlexGridSizer(rows=1,cols=3,hgap=5,vgap=5)
        head.AddMany([cmd,self.stringtext,self.button])
        text =wx.StaticBox(panel, -1, 'setting')
        bsizer = wx.StaticBoxSizer(text, wx.VERTICAL)
        control = wx.TextCtrl(panel,style=wx.TE_MULTILINE|wx.TE_LINEWRAP)
        bsizer.Add(control, flag=wx.EXPAND|wx.ALL)
        sizer = self.LayoutPanel(head, bsizer)
        panel.SetSizer(sizer)
    
    def LayoutPanel(self, head, days):
        bsizer = wx.BoxSizer(wx.VERTICAL)
        bsizer.Add(head, flag=wx.EXPAND)
        bsizer.Add(days, flag=wx.EXPAND)
        return bsizer    


------解决方案--------------------
def __init__(self):
    ...
    bsizer.Add(control, 1, wx.EXPAND
------解决方案--------------------
wx.ALL)
    ...

def LayoutPanel(self, head, days):
    ...
    bsizer.Add(days, 1, wx.EXPAND)
    ...