Wpf- -如何获得触发TreeViewItem.Loaded事件的TreeViewItem.Loaded？

Question

我试图在每个TreeViewItem加载时附加一些处理程序，然后在卸载处理程序时删除它们。

下面是我从TreeView继承的自定义控件中的代码

public ModdedTreeView()
    {
        this.AddHandler(TreeViewItem.LoadedEvent, new RoutedEventHandler(ItemLoaded));            

        this.AddHandler(TreeViewItem.UnloadedEvent, new RoutedEventHandler(ItemUnloaded));
    }

    protected void ItemLoaded(object sender, RoutedEventArgs e)
    {
        TreeViewItem item = e.OriginalSource as TreeViewItem;

        if (item == null)
            return;

        item.AddHandler(TreeViewItem.CollapsedEvent, new RoutedEventHandler(ItemCollapsed));

        item.AddHandler(TreeViewItem.ExpandedEvent, new RoutedEventHandler(ItemExpanded));

        item.AddHandler(TreeViewItem.SelectedEvent, new RoutedEventHandler(ItemSelected));
    }


    protected void ItemUnloaded(object sender, RoutedEventArgs e)
    {
        TreeViewItem item = e.OriginalSource as TreeViewItem;

        if (item == null)
            return;

        item.RemoveHandler(TreeViewItem.CollapsedEvent, new RoutedEventHandler(ItemCollapsed));

        item.RemoveHandler(TreeViewItem.ExpandedEvent, new RoutedEventHandler(ItemExpanded));

        item.RemoveHandler(TreeViewItem.SelectedEvent, new RoutedEventHandler(ItemSelected));
    }

编辑：

我还是搞不懂到底是怎么回事。它似乎只是选择了TreeView加载的事件，而不是TreeViewItem加载的事件。

Answer 1

Loaded是一个路由事件，因此您将在OriginalSource属性中找到它的源，该属性应该是触发事件的treeviewitem。