应对listctrl的变化恰好一次

Question

我在窗体上使用的wxPython，我想改变基于其他的listctrl的选择值的想要的listctrl的名单工作。要做到这一点，我使用链接到控制对象的EVT_LIST_ITEM_SELECTED和EVT_LIST_ITEM_DESELECTED事件调用Publisher.sendMessage方法。要改变的控制具有是订户到发布商的方法。这个作品：当单击第一的listctrl时，第二刷新

的问题是，该数据必须从数据库被刷新并为每选择和取消选择被发送的消息。这意味着，即使我只需点击一个项目，数据库查询得到两次（一次为取消选择，然后再进行选择）。如果我按住Shift键单击多选择5个项目，然后5次调用就会做出。有没有什么办法都设定了的listctrl响应，而不是个人的选择？

Answer 1

最好的解决办法似乎是使用wx.CallAfter带有标志准确地执行一次后续程序：

import wx

class MyFrame(wx.Frame):
    def __init__(self, *args, **kwds):
        wx.Frame.__init__(self, *args, **kwds)
        self.list_ctrl_1 = wx.ListCtrl(self, -1, style=wx.LC_REPORT|wx.SUNKEN_BORDER)
        sizer_1 = wx.BoxSizer(wx.HORIZONTAL)
        sizer_1.Add(self.list_ctrl_1, 1, wx.EXPAND, 0)
        self.list_ctrl_1.InsertColumn(0,"1")
        self.list_ctrl_1.InsertStringItem(0,"HELLO1")
        self.list_ctrl_1.InsertStringItem(0,"HELLO2")
        self.list_ctrl_1.InsertStringItem(0,"HELLO3")
        self.list_ctrl_1.InsertStringItem(0,"HELLO4")
        self.list_ctrl_1.InsertStringItem(0,"HELLO5")
        self.list_ctrl_1.InsertStringItem(0,"HELLO6")
        self.Bind(wx.EVT_LIST_ITEM_SELECTED, self.OnItemSelected, self.list_ctrl_1)
        self.Bind(wx.EVT_LIST_ITEM_DESELECTED, self.OnItemDeselected, self.list_ctrl_1)
        self.dirty = False
    def Cleanup(self, StringToPrint):
        print 'No Longer Dirty!'
        self.dirty = False

    def OnItemSelected(self,event):
        print str(self.__class__) + " - OnItemSelected"
        if not self.dirty:
            self.dirty = True
            wx.CallAfter(self.Cleanup)
        event.Skip()

    def OnItemDeselected(self,event):
        print str(self.__class__) + " - OnItemDeselected"
        if not self.dirty:
            self.dirty = True
            wx.CallAfter(self.Cleanup)
        event.Skip()

if __name__ == "__main__":
    app = wx.PySimpleApp(0)
    wx.InitAllImageHandlers()
    frame_1 = MyFrame(None, -1, "")
    app.SetTopWindow(frame_1)
    frame_1.Show()
    app.MainLoop()

Answer 2

您可以尝试EVT_LIST_ITEM_RIGHT_CLICK。这应该工作。否则，你会想用一个标志，每一次检查说标志选择事件触发，看它是否需要查询数据库或没有。另外还有UltimateListCtrl，一个纯Python窗口小部件，或许您可以破解成这样的。

Answer 3

可以在一个自定义的事件处理程序推

import wx

class MyEventHandler(wx.PyEvtHandler):
        def __init__(self,target):
            self.target = target
            wx.PyEvtHandler.__init__(self)

        def ProcessEvent(self,event):
            # there must be a better way of getting the event type,
            # but I couldn't find it
            if event.GetEventType() == wx.EVT_LEFT_DOWN.evtType[0]:
                print "Got Mouse Down event"
                (item,where) = self.target.HitTest(event.GetPosition())
                if item != -1:
                    print self.target.GetItem(item,0).GetText()
                    print where
                else:
                    print "Not on list item though"
                return True
            else:
                return False

class MyFrame(wx.Frame):
        def __init__(self, *args, **kwds):
           wx.Frame.__init__(self, *args, **kwds)
           self.list_ctrl_1 = wx.ListCtrl(self, -1, style=wx.LC_REPORT|wx.SUNKEN_BORDER)
           self.myevthandler = MyEventHandler(self.list_ctrl_1)
           sizer_1 = wx.BoxSizer(wx.HORIZONTAL)
           sizer_1.Add(self.list_ctrl_1, 1, wx.EXPAND, 0)
           self.list_ctrl_1.InsertColumn(0,"1")
           self.list_ctrl_1.InsertStringItem(0,"HELLO1")
           self.list_ctrl_1.PushEventHandler(self.myevthandler)


if __name__ == "__main__":
    app = wx.PySimpleApp(0)
    wx.InitAllImageHandlers()
    frame_1 = MyFrame(None, -1, "")
    app.SetTopWindow(frame_1)
    frame_1.Show()
    app.MainLoop()