wxpython:如何检查OnDragOver中的拖动数据？

import wx

class MyFrame(wx.Frame):
    def __init__(self, parent, title):
        super(MyFrame, self).__init__(parent, title=title, size=(300, 200))

        self.panel = wx.Panel(self)
        self.panel.Bind(wx.EVT_DROP_FILES, self.OnDropFiles)

        self.drop_target = wx.FileDropTarget()
        self.drop_target.Bind(wx.EVT_DROP_FILES, self.OnDropFiles)
        self.panel.SetDropTarget(self.drop_target)

    def OnDropFiles(self, event):
        files = event.GetFiles()
        if len(files) > 0:
            print("Dragged file: ", files[0])

app = wx.App(False)
frame = MyFrame(None, "Drag and Drop Example")
frame.Show(True)
app.MainLoop()