贴上源代码

#-* coding:GBK *-
import os
import wx

def create(parent):
    return Frame1(parent)

# assign ID numbers
[wxID_FRAME1, wxID_FRAME1BUTTON1, wxID_FRAME1BUTTON2, wxID_FRAME1LISTBOX1,
] = [wx.NewId() for _init_ctrls in range(4)]

class Frame1(wx.Frame):
    def _init_ctrls(self, prnt):
        # BOA generated methods
        wx.Frame.__init__(self, id=wxID_FRAME1, name='', parent=prnt,
              pos=wx.Point(400, 400), size=wx.Size(500, 400),
              style=wx.DEFAULT_FRAME_STYLE, title='改系统hosts，需要把要修改的hosts文件放在hosts目录下面')

        self.SetClientSize(wx.Size(750, 300))

        self.listBox1 = wx.ListBox(choices=[], id=wxID_FRAME1LISTBOX1,
              name='listBox1', parent=self, pos=wx.Point(10, 10),
              size=wx.Size(200, 240), style=0)

        self.t1 = wx.TextCtrl(self, -1,"",size=(520, 280), pos=wx.Point(220, 10),style=wx.TE_MULTILINE|wx.TE_PROCESS_ENTER)

        '''列表目录中所有文件'''
        for i in os.listdir('./hosts/'):
            self.listBox1.Append(i)   

        self.listBox1.Bind(wx.EVT_LISTBOX, self.OnListBox1Listbox,
              id=wxID_FRAME1LISTBOX1)            

        self.button2 = wx.Button(id=wxID_FRAME1BUTTON2, label='改写系统hosts',
              name='button2', parent=self, pos=wx.Point(10, 260),
              size=wx.Size(200, 30), style=0)

        self.button2.Bind(wx.EVT_BUTTON, self.OnButton2Button,
              id=wxID_FRAME1BUTTON2)

    def __init__(self, parent):
        self._init_ctrls(parent)

    def OnListBox1Listbox(self, event):
        selName = './hosts/' + self.listBox1.GetStringSelection()
        #self.SetTitle(selName)       

        f = open(selName, "r+")
        try:
            all_the_text = f.read( )
        finally:
            f.close()
        self.t1.Clear()
        self.t1.write(all_the_text)        

    def OnButton2Button(self, event):
        x = os.getenv('WINDIR')+"\system32\drivers\etc\hosts"
        v = self.t1.GetValue();
        v = v.encode('gb2312')
        f = open(x, 'w')
        f.writelines(v)
        f.close( )        

#--------------- end of class Frame1 --------------------

# program entry point ...
if __name__ == '__main__':
    app = wx.PySimpleApp()
    wx.InitAllImageHandlers()
    frame = create(None)
    frame.Show()

    app.MainLoop()