从其他类别中检索值

如何解决从其他类别中检索值

我在尝试在程序的拖放区中检索值时遇到麻烦。 真的很抱歉，我是Python和OOP的新手，所以对不起，如果我的问题有点傻。

我的目标是在DnDPanel类中单击按钮（btn）后检索放置在拖放区域中的文件名。 我尝试了很多事情，但是仍然无法从'OnDropFiles'方法访问'filenames'值，我创建了'buff_pdf'方法来执行此操作，但是它不起作用。 我一定在做错事，但我不知道该怎么办。 谢谢您的帮助！

import wx

########################################################################
class MyFileDropTarget(wx.FileDropTarget):
    """"""

    #----------------------------------------------------------------------
    def __init__(self,window):
        """Constructor"""
        wx.FileDropTarget.__init__(self)
        self.window = window
       
    #----------------------------------------------------------------------
    def OnDropFiles(self,x,y,filenames):
        """
        Quand les fichiers sont glissés,écrit le chemin depuis lequel
        ils viennent
        """
        self.window.SetInsertionPointEnd()
        self.window.updateText("\n%d fichier reçu %d,%d:\n" %
                              (len(filenames),y))
        for filepath in filenames:
            self.window.updateText(filepath + '\n')

        return True
        
########################################################################
class DnDPanel(wx.Panel,MyFileDropTarget):

    #----------------------------------------------------------------------
    def __init__(self,parent):
        """Constructor"""
        wx.Panel.__init__(self,parent=parent)
        file_drop_target = MyFileDropTarget(self)
        lbl = wx.StaticText(self,label="Put your PDF file in the drop zone :")
        self.fileTextCtrl = wx.TextCtrl(self,style=wx.TE_MULTILINE|wx.HSCROLL|wx.TE_READONLY)
        self.fileTextCtrl.SetDropTarget(file_drop_target)
        btn = wx.Button(self,label='buff files')
        #Retrieve filenames onclick
        btn.Bind(wx.EVT_BUTTON,self.buff_pdf)
        sizer = wx.BoxSizer(wx.VERTICAL)
        sizer.Add(lbl,wx.ALL,25)
        sizer.Add(self.fileTextCtrl,1,wx.EXPAND|wx.ALL,5)
        self.SetSizer(sizer)

#----------------------------------------------------------------------

    def buff_pdf(self,event,MyFileDropTarget):
        """
        Retrieve filenames after clicking on the button (btn)
        """
        MyFileDropTarget.OnDropFiles(self)
        obj = MyFileDropTarget(self)
        obj.OnDropFiles(self)
        print(self.filenames)
        
    #----------------------------------------------------------------------
    def SetInsertionPointEnd(self):
        """
        Put insertion point at end of text control to prevent overwriting
        """
        self.fileTextCtrl.SetInsertionPointEnd()
        
    #----------------------------------------------------------------------
    def updateText(self,text):
        """
        Write text to the text control
        """
        self.fileTextCtrl.WriteText(text)

########################################################################
class DnDFrame(wx.Frame):
    """"""

    #----------------------------------------------------------------------
    def __init__(self):
        """Constructor"""
        wx.Frame.__init__(self,parent=None,title="PDF Buffer")
        panel = DnDPanel(self)
        self.Show()

########################################################################

if __name__ == "__main__":
    app = wx.App(False)
    frame = DnDFrame()
    app.MainLoop()

解决方法

主要问题是DnDPanel继承自MyFileDropTarget，并且还创建了MyFileDropTarget的子实例。最好只创建子实例并对其进行访问。

filenames变量也需要定义为MyFileDropTarget类的属性，以便从父级访问。

这是工作代码：

import wx

########################################################################
class MyFileDropTarget(wx.FileDropTarget):
    """"""

    #----------------------------------------------------------------------
    def __init__(self,window):
        """Constructor"""
        wx.FileDropTarget.__init__(self)
        self.window = window
        self.filenames = []   # create attribute for later reference
       
    #----------------------------------------------------------------------
    def OnDropFiles(self,x,y,filenames):
        """
        Quand les fichiers sont glissés,écrit le chemin depuis lequel
        ils viennent
        """
        self.window.SetInsertionPointEnd()
        self.window.updateText("\n%d fichier reçu %d,%d:\n" %
                              (len(filenames),y))
        for filepath in filenames:
            self.window.updateText(filepath + '\n')
        
        self.filenames.extend(filenames)   # update attribute

        return True
        
########################################################################
class DnDPanel(wx.Panel):

    #----------------------------------------------------------------------
    def __init__(self,parent):
        """Constructor"""
        wx.Panel.__init__(self,parent=parent)
        self.file_drop_target = MyFileDropTarget(self)  # create child object
        lbl = wx.StaticText(self,label="Put your PDF file in the drop zone :")
        self.fileTextCtrl = wx.TextCtrl(self,style=wx.TE_MULTILINE|wx.HSCROLL|wx.TE_READONLY)
        self.fileTextCtrl.SetDropTarget(self.file_drop_target)
        btn = wx.Button(self,label='buff files')
        #Retrieve filenames onclick
        btn.Bind(wx.EVT_BUTTON,self.buff_pdf)
        sizer = wx.BoxSizer(wx.VERTICAL)
        sizer.Add(lbl,wx.ALL,25)
        sizer.Add(self.fileTextCtrl,1,wx.EXPAND|wx.ALL,5)
        self.SetSizer(sizer)

#----------------------------------------------------------------------

    def buff_pdf(self,event):
        """
        Retrieve filenames after clicking on the button (btn)
        """
        # MyFileDropTarget.OnDropFiles(self)
        # obj = MyFileDropTarget(self)
        # obj.OnDropFiles(self)
        print(self.file_drop_target.filenames)  # from child object
        
    #----------------------------------------------------------------------
    def SetInsertionPointEnd(self):
        """
        Put insertion point at end of text control to prevent overwriting
        """
        self.fileTextCtrl.SetInsertionPointEnd()
        
    #----------------------------------------------------------------------
    def updateText(self,text):
        """
        Write text to the text control
        """
        self.fileTextCtrl.WriteText(text)

########################################################################
class DnDFrame(wx.Frame):
    """"""

    #----------------------------------------------------------------------
    def __init__(self):
        """Constructor"""
        wx.Frame.__init__(self,parent=None,title="PDF Buffer")
        panel = DnDPanel(self)
        self.Show()

########################################################################

if __name__ == "__main__":
    app = wx.App(False)
    frame = DnDFrame()
    app.MainLoop()