TreeViewItem.Expanded 事件

定义

命名空间:

System.Windows.Controls

程序集:

PresentationFramework.dll

当 IsExpanded 属性从 false 更改为 true 时发生。

public:
 event System::Windows::RoutedEventHandler ^ Expanded;

public event System.Windows.RoutedEventHandler Expanded;

member this.Expanded : System.Windows.RoutedEventHandler 

Public Custom Event Expanded As RoutedEventHandler 

事件类型

RoutedEventHandler

示例

以下示例演示如何将 事件的事件处理程序 Expanded 分配给 ， TreeViewItem 以及如何在代码隐藏中定义事件处理程序。

<TreeViewItem Header="Employee1"
              Name="Employee1Data" 
              IsExpanded="True" 
              Collapsed="OnCollapsed" 
              Expanded="OnExpanded">
  <TreeViewItem Header="Work Days" 
                Name="EmployeeWorkDays"
                IsSelected="True">
    <TreeViewItem Header="Tuesday" />
    <TreeViewItem Header="Friday"/>
  </TreeViewItem>
</TreeViewItem>
<TreeViewItem Header="Employee2" 
              Name="Employee2Data">
  <TreeViewItem Header="Work Days" 
                Name="emp2WorkDays" 
                Selected="GetSchedule"
                Unselected="SetSchedule">
    <TreeViewItem Header="Monday" />
    <TreeViewItem Header="Wednesday"/>
  </TreeViewItem>
</TreeViewItem>

private void OnExpanded(object sender, RoutedEventArgs e)
{
    //Perform actions when the TreeViewItem is expanded
}

Private Sub OnExpanded(ByVal sender As Object, ByVal e As RoutedEventArgs)
    'Perform actions when the TreeViewItem is expanded
End Sub

注解

当 展开以便其子元素可见时 TreeViewItem ，会发生此事件。

路由事件信息

标识符字段	ExpandedEvent
路由策略	鼓 泡
委托	RoutedEventHandler

另请参阅

• IsExpanded
• Collapsed