python - wxpython 将变量传递给回调事件。 lambda 岛

Question

我是不是对 lambda 不了解？或者 GetValue() 我试图传递的变量是空的。最好为此创建一个 global palletNumberText 吗？在 createWidgets() 中，我绑定(bind)了一个 EVT_TEXT，这样当在 TextCtrl 中输入文本时，它应该调用 onPalletNumberText(event, variable_here )

下一行是我遇到困难的地方:

palletNumberText.Bind(wx.EVT_TEXT, lambda event, temp_str=palletNumberText.GetValue(): self.onPalletNumberText( event, temp_str ))

在这里面代码片段:

class ClassName(wx.Frame):
    def __init__(self, parent, title):
        wx.Frame.__init__(self, parent, title=title)
        self.panel = wx.Panel(self)
        self.PhotoMaxSize = 240
        self.createWidgets()
        self.Show()

    def createWidgets(self):
        .
        .
        .
        palletNumberText = wx.TextCtrl(self.panel, size=(80,-1))
        # THIS LINE
        palletNumberText.Bind(wx.EVT_TEXT, lambda event, temp_str=palletNumberText.GetValue(): self.onPalletNumberText( event, temp_str ))
        .
        .
        .

    def onPalletNumberText(self, event, palletNumber):
        '''
        save palletNumbertTxt Value when text is entered
        '''
        print palletNumber
        print "This is a test"
        # Store Value

        return

我看过的读物:

• wxpython, passing data to a function in self.Bind
• http://wiki.wxpython.org/Passing%20Arguments%20to%20Callbacks
• wxpython passing information, pointers?
• How can I give variables to the event handler?
• Is it possible to pass arguments into event bindings?
• http://wxpython-users.1045709.n5.nabble.com/GetValue-from-TextCtrl-by-hitting-a-button-td3203210.html
• Getting String from A TextCtrl Box

但是我的结果:

谢谢。

Answer 1

你的默认参数在开始时计算

lambda event, temp_str=None: self.onPalletNumberText( event, 
                             temp_str if temp_str is not None else palletNumberText.GetValue() )

我觉得可以

但你真正想要的可能更像

lambda event, txt_instance=palletNumberText: self.onPalletNumberText( event, txt_instance.GetValue() )