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我正在使用 TreeView (System.Windows.Controls.TreeView) 的 WPF 版本，需要分配几个事件。由于这些是 WPF，大多数事件要么不同，要么行为方式不同，因此我感到困惑，因为 AfterExpand 不可用

现在我需要 2 个事件：

处于 TreeView 级别的 SelectedItemChanged 处于 TreeViewItem 级别的 ExpandedEvent

到目前为止我有

    private void DisplayGetEventTypes(UXEvent.GetEventTypesResp resp, CustomAsyncStateContainer state)
    {

        navBarControl.Groups.Clear();

        if (resp.eventTypeItems != null)
        {
            UXEvent.EventType[] eventItems = resp.eventTypeItems;

            int nodeCount = eventItems.Length;
            for (int i = 0; i < nodeCount; i++)
            {
                UXEvent.TryEvent eventItem = new UXEvent.TryEvent();
                eventItem.eventName = eventItems[i].name;
                eventItem.eventId = eventItems[i].id;

                NavBarGroup group1 = new NavBarGroup();

                group1.Header = eventItems[i].name;
                group1.Tag = eventItem;

                group1.IsExpanded = false;

                //Add dummy treeview to fill later if expanded
                System.Windows.Controls.TreeView treeview = new System.Windows.Controls.TreeView();
                treeview.SelectedItemChanged += new RoutedPropertyChangedEventHandler<object>(myTreeView_SelectedItemChanged);
                AddHandler(TreeViewItem.ExpandedEvent, new RoutedEventHandler(myTreeView_ItemExpanded));
                group1.Content = treeview;
                group1.DisplaySource = DisplaySource.Content;

                navBarControl.Groups.Add(group1);

            }

        }
    }

以及以下两个用于测试的草稿事件处理程序

    void myTreeView_SelectedItemChanged(object sender,
    RoutedPropertyChangedEventArgs<object> e)
    {
        // Set the data context of the text block to the selected value.
        var node = (ItemsControl)e.OriginalSource;
        System.Windows.Forms.MessageBox.Show("Selected!");

    }

    void myTreeView_ItemExpanded(object sender, RoutedEventArgs e)
    {
        // Set the data context of the text block to the selected value.
        var node = (TreeViewItem)e.OriginalSource;

        System.Windows.Forms.MessageBox.Show("Opening! - " + node.Header);

    }

我遇到的问题是，myTreeView_ItemExpanded当任何 treeviewItem 展开时会触发多次。我认为由于事件冒泡它会触发多次。

首先，谁能指出我可以阅读这种行为的一些好的资源？

其次，我怎样才能修改我的代码AddHandler(TreeViewItem.ExpandedEvent, new RoutedEventHandler(myTreeView_ItemExpanded));只做一个事件？

谢谢

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1 回答 1

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我发现了问题。线

AddHandler(TreeViewItem.ExpandedEvent, new RoutedEventHandler(myTreeView_ItemExpanded));

应该读

treeview.AddHandler(TreeViewItem.ExpandedEvent, new RoutedEventHandler(myTreeView_ItemExpanded));

我假设第一行必须已将事件处理程序添加到所有可用控件，并且在事件触发时全部触发。

于 2012-08-26T17:16:54.393 回答