SelectionChangedEventArgs 类

定义

命名空间:

System.Windows.Controls

程序集:

PresentationFramework.dll

为 SelectionChanged 事件提供数据。

public ref class SelectionChangedEventArgs : System::Windows::RoutedEventArgs

public class SelectionChangedEventArgs : System.Windows.RoutedEventArgs

type SelectionChangedEventArgs = class
    inherit RoutedEventArgs

Public Class SelectionChangedEventArgs
Inherits RoutedEventArgs

继承

Object

EventArgs

RoutedEventArgs

SelectionChangedEventArgs

示例

以下示例创建 ListBox 并订阅 事件 SelectionChanged 。 它使用 SelectionChangedEventArgs 在 中 ListBox查找所选项。

<WrapPanel Width="500" Orientation="Horizontal" Name="rectanglesPanel">
  <WrapPanel.Resources>
    <Style TargetType="Rectangle">
      <Setter Property="Height" Value="20"/>
      <Setter Property="Width" Value="20"/>
      <Setter Property="Margin" Value="5"/>
    </Style>
  </WrapPanel.Resources>
</WrapPanel>

<ListBox Name="myListBox" HorizontalAlignment="Left" SelectionMode="Extended" 
      Width="265" Height="55" Background="HoneyDew" SelectionChanged="myListBox_SelectionChanged"
      ItemsSource="{Binding Source={StaticResource Colors}}" IsSynchronizedWithCurrentItem="true">
</ListBox>

void myListBox_SelectionChanged(object sender, SelectionChangedEventArgs args)
{

    BrushConverter converter = new BrushConverter();

    // Show Rectangles that are the selected colors.
    foreach (string color in args.AddedItems)
    {
        if (GetRectangle(color) == null)
        {
            Rectangle aRect = new Rectangle();
            aRect.Fill = (Brush) converter.ConvertFrom(color);
            aRect.Tag = color;
            rectanglesPanel.Children.Add(aRect);
        }
    }

    // Remove the Rectangles that are the unselected colors.
    foreach (string color in args.RemovedItems)
    {
        FrameworkElement removedItem = GetRectangle(color);
        if (removedItem != null)
        {
            rectanglesPanel.Children.Remove(removedItem);
        }
    }
}

FrameworkElement GetRectangle(string color)
{
    foreach (FrameworkElement rect in rectanglesPanel.Children)
    {
        if (rect.Tag.ToString() == color)
            return rect;
    }

    return null;
}

Private Sub myListBox_SelectionChanged(ByVal sender As Object, ByVal args As SelectionChangedEventArgs)

    Dim converter As BrushConverter = New BrushConverter()
    Dim color As String

    ' Show Rectangles that are the selected colors.
    For Each color In args.AddedItems

        If GetRectangle(color) Is Nothing Then
            Dim aRect As Rectangle = New Rectangle()
            aRect.Fill = CType(converter.ConvertFrom(color), Brush)
            aRect.Tag = color
            rectanglesPanel.Children.Add(aRect)
        End If

    Next

    ' Remove the Rectangles that are the unselected colors.
    For Each color In args.RemovedItems

        Dim removedItem As FrameworkElement = GetRectangle(color)
        If Not removedItem Is Nothing Then
            rectanglesPanel.Children.Remove(removedItem)
        End If

    Next

End Sub

Private Function GetRectangle(ByVal color As String) As FrameworkElement
    Dim rect As FrameworkElement
    For Each rect In rectanglesPanel.Children
        If rect.Tag.ToString() = color Then
            Return rect
        End If
    Next

    Return Nothing
End Function

构造函数

SelectionChangedEventArgs(RoutedEvent, IList, IList)

初始化 SelectionChangedEventArgs 类的新实例。

属性

AddedItems	获取包含选定项的列表。
Handled	获取或设置一个值，该值指示针对路由事件（在其经过路由时）的事件处理的当前状态。 (继承自 RoutedEventArgs)
OriginalSource	在父类进行任何可能的 Source 调整之前，获取由纯命中测试确定的原始报告源。 (继承自 RoutedEventArgs)
RemovedItems	获取包含未选定项的列表。
RoutedEvent	获取或设置与此 RoutedEventArgs 实例关联的 RoutedEvent。 (继承自 RoutedEventArgs)
Source	获取或设置对引发事件的对象的引用。 (继承自 RoutedEventArgs)

方法

Equals(Object)	确定指定对象是否等于当前对象。 (继承自 Object)
GetHashCode()	作为默认哈希函数。 (继承自 Object)
GetType()	获取当前实例的 Type。 (继承自 Object)
InvokeEventHandler(Delegate, Object)	执行适当类型的强制转换，以为 SelectionChangedEventHandler 事件调用类型安全的 SelectionChanged 委托。
MemberwiseClone()	创建当前 Object 的浅表副本。 (继承自 Object)
OnSetSource(Object)	在派生类中重写时，每当实例的 Source 属性的值发生更改，则提供一个通知回调入口点。 (继承自 RoutedEventArgs)
ToString()	返回表示当前对象的字符串。 (继承自 Object)

另请参阅

• RoutedEventArgs