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Wpf- How can I get the TreeViewItem that triggered the TreeViewItem.Loaded event?

开发者 https://www.devze.com 2023-01-13 20:55 出处:网络
I am trying to attach some handlers to each TreeViewItem as they are loaded and then remove the handlers as they are unloaded.

I am trying to attach some handlers to each TreeViewItem as they are loaded and then remove the handlers as they are unloaded.

Here is the Code that I have in my custom control which inherits from TreeView:

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

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

    protected void ItemLoaded(object se开发者_JAVA技巧nder, 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));
    }

Edit:

I still can not figure out what is going on. It just seems to be picking up the TreeView loaded event instead of the TreeViewItem loaded event.


Loaded is a routed event, so you will find its source in the OriginalSource property, which should be the treeviewitem that triggered the event.


Apparently the TreeViewItem.Loaded event is a direct event. So there is no way to accomplish what I was trying.

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