在WPF中为TreeViewItem创建事件处理程序

在WPF中为TreeViewItem创建事件处理程序,wpf,binding,treeview,Wpf,Binding,Treeview,Im通过ItemsSource属性和ItemTemplate属性向TreeView控件添加项,以设置TreeView项的模板。如何添加事件处理程序来处理TreeViewItems上的选择更改事件? 目前,我的ItemTemplate如下所示: <Window.Resources><DataTemplate x:Key="PeerDetailTemplate"> <TextBlock Text="{Binding DESCRIPTION}" Tag="

Im通过ItemsSource属性和ItemTemplate属性向TreeView控件添加项,以设置TreeView项的模板。如何添加事件处理程序来处理TreeViewItems上的选择更改事件?
目前,我的ItemTemplate如下所示:

<Window.Resources><DataTemplate x:Key="PeerDetailTemplate">
        <TextBlock Text="{Binding DESCRIPTION}" Tag="{Binding ID}" GotFocus="GetModules"/>
</DataTemplate></Window.Resources>


但是它不起作用(不调用GetModules)。我是WPF新手,请告诉我做这些事情的正确方向。

您需要向TreeView的SelectedItemChanged事件添加事件处理程序

<TreeView x:Name="myTreeView"
          SelectedItemChanged="myTreeView_SelectedItemChanged"
          ItemTemplate="{StaticResource PeerDetailTemplate} />

如果要在中捕获事件,则需要在父节点上设置事件处理程序,即

XAML

<StackPanel>
    <TreeView SelectedItemChanged="OnTreeViewSelectedItemChanged">          
        <TreeViewItem Header="Desktop">
            <TreeViewItem Header="Computer" />
            <TreeViewItem Header="My Documents" />
            <TreeViewItem Header="c:\" />
        </TreeViewItem>
        <TreeViewItem Header="Recyle Bin" >
            <TreeViewItem Header="foo.txt" />
            <TreeViewItem Header="bar.txt" />
            <TreeViewItem Header="fizz.buzz" />
        </TreeViewItem>
        <TreeViewItem Header="Control Panel" >
            <TreeViewItem Header="Programs" />
            <TreeViewItem Header="Security" />
            <TreeViewItem Header="User Accounts" />
        </TreeViewItem>
    </TreeView>

    <TextBlock Margin="20" x:Name="MyTextBlock" />
</StackPanel>

代码隐藏

private void OnTreeViewSelectedItemChanged( object sender, RoutedPropertyChangedEventArgs<object> e )
{
    MyTextBlock.Text = ( (TreeViewItem) ( (TreeView) sender ).SelectedItem ).Header.ToString();
}
private void OnTreeViewSelectedItemChanged(对象发送方,RoutedPropertyChangedEventArgs e)
{
MyTextBlock.Text=((TreeView)sender.SelectedItem.Header.ToString();
}

选择和选择与焦点是两个不同的概念。听起来您对选择感兴趣,在本例中,选择是TreeView的一个属性。事件将通知您选择的更改,属性将告诉您选择的内容。

有不同的方法绑定TreeItem的SelectedItemChanged事件:

方法1:直接连接事件

事件的附件可以在Xaml中完成

<TreeView x:Name="treeview1" HorizontalAlignment="Left" Height="243" Margin="30,211,0,0" VerticalAlignment="Top" Width="667" SelectedItemChanged="TreeView_SelectedItemChanged">
        <TreeViewItem Header="TreeViewItem"/>
</TreeView>
Private void TreeView_SelectedItemChanged(object sender, RoutedPropertyChangedEventArgs<object> e)
{

}
方法3行为的使用

public class BindableSelectedItemBehavior : Behavior<TreeView>
{
    #region SelectedItem Property

    public object SelectedItem
    {
        get { return (object)GetValue(SelectedItemProperty); }
        set { SetValue(SelectedItemProperty, value); }
    }

    public static readonly DependencyProperty SelectedItemProperty =
        DependencyProperty.Register("SelectedItem", typeof(object), typeof(BindableSelectedItemBehavior), new UIPropertyMetadata(null, OnSelectedItemChanged));

    private static void OnSelectedItemChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
    {
        var item = e.NewValue as TreeViewItem;
        if (item != null)
        {
            item.SetValue(TreeViewItem.IsSelectedProperty, true);
        }
    }

    #endregion

    protected override void OnAttached()
    {
        base.OnAttached();

        this.AssociatedObject.SelectedItemChanged += OnTreeViewSelectedItemChanged;
    }

    protected override void OnDetaching()
    {
        base.OnDetaching();

        if (this.AssociatedObject != null)
        {
            this.AssociatedObject.SelectedItemChanged -= OnTreeViewSelectedItemChanged;
        }
    }

诚恳地说

是的,就像前面的回答所说的那样……这很有帮助。谢谢大家的回答,但作为回答,我会在第一个问题上打分。其余部分将为+1,这是否意味着即使是深入到TreeView结构中的TreeViewItem也将显示在SelectedItem中?是的,SelectedItemChanged事件将始终捕获当前SelectedItem(TreeViewItem),无论TreeViewItem在TreeView中嵌套得有多深。
myTreeview.SelectedItemChanged += new RoutedPropertyChangedEventHandler<object>(TreeView_SelectedItemChanged);

private void TreeView_SelectedItemChanged(object sender, RoutedPropertyChangedEventArgs<object> e)
{

}
public class ExtendedTreeView : TreeView
{
    public ExtendedTreeView()
        : base()
    {
        this.SelectedItemChanged += new RoutedPropertyChangedEventHandler<object>(TreeView_SelectedItemChanged);
    }

    void TreeView_SelectedItemChanged(object sender, RoutedPropertyChangedEventArgs<object> e)
    {
        if (SelectedItem != null)
        {
            SetValue(SelectedItem_Property, SelectedItem);
        }
    }

    public object SelectedItem_
    {
        get { return (object)GetValue(SelectedItem_Property); }
        set { SetValue(SelectedItem_Property, value); }
    }
    public static readonly DependencyProperty SelectedItem_Property = DependencyProperty.Register("SelectedItem_", typeof(object), typeof(ExtendedTreeView), new UIPropertyMetadata(null));
}
ExtendedTreeView  myTreeview = new ExtendedTreeView();
public class BindableSelectedItemBehavior : Behavior<TreeView>
{
    #region SelectedItem Property

    public object SelectedItem
    {
        get { return (object)GetValue(SelectedItemProperty); }
        set { SetValue(SelectedItemProperty, value); }
    }

    public static readonly DependencyProperty SelectedItemProperty =
        DependencyProperty.Register("SelectedItem", typeof(object), typeof(BindableSelectedItemBehavior), new UIPropertyMetadata(null, OnSelectedItemChanged));

    private static void OnSelectedItemChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
    {
        var item = e.NewValue as TreeViewItem;
        if (item != null)
        {
            item.SetValue(TreeViewItem.IsSelectedProperty, true);
        }
    }

    #endregion

    protected override void OnAttached()
    {
        base.OnAttached();

        this.AssociatedObject.SelectedItemChanged += OnTreeViewSelectedItemChanged;
    }

    protected override void OnDetaching()
    {
        base.OnDetaching();

        if (this.AssociatedObject != null)
        {
            this.AssociatedObject.SelectedItemChanged -= OnTreeViewSelectedItemChanged;
        }
    }
<TreeView>
    <e:Interaction.Behaviors>
        <behaviours:BindableSelectedItemBehavior SelectedItem="{Binding SelectedItem, Mode=TwoWay}" />
    </e:Interaction.Behaviors>
</TreeView>
BindableSelectedItemBehavior selectedItemBehavior = new BindableSelectedItemBehavior();
System.Windows.Interactivity.Interaction.GetBehaviors(treeview1).Add(selectedItemBehavior);