HierarchicalDataTemplate.ItemContainerStyleSelector Propiedad

public:
 property System::Windows::Controls::StyleSelector ^ ItemContainerStyleSelector { System::Windows::Controls::StyleSelector ^ get(); void set(System::Windows::Controls::StyleSelector ^ value); };

public System.Windows.Controls.StyleSelector ItemContainerStyleSelector { get; set; }

member this.ItemContainerStyleSelector : System.Windows.Controls.StyleSelector with get, set

Public Property ItemContainerStyleSelector As StyleSelector

Valor de propiedad

StyleSelector

StyleSelector que elige qué estilo se usará como ItemContainerStyle. De manera predeterminada, es null.

Ejemplos

En el ejemplo siguiente se crea un TreeView objeto que usa el ItemContainerStyle de HierarchicalDataTemplate para elegir entre dos estilos para los elementos del segundo nivel de .TreeView

<StackPanel Name="sp1" x:FieldModifier="public">
  <StackPanel.Resources>
    <src:TreeViewData x:Key="dataItems"/>

    <Style x:Key="TreeViewItemStyle1"  TargetType="TreeViewItem">
      <Setter Property="Foreground" Value="Navy"/>
      <Setter Property="FontStyle" Value="Italic"/>
    </Style>

    <Style x:Key="TreeViewItemStyle2"  TargetType="TreeViewItem">
      <Setter Property="Foreground" Value="Green"/>
      <Setter Property="FontWeight" Value="Bold"/>
    </Style>

    <src:TreeViewItemStyleSelector x:Key="tviSelector"/>
    
    <HierarchicalDataTemplate DataType="{x:Type src:ItemsForTreeView}"
                              ItemsSource="{Binding Path=SecondLevelItems}"
                              ItemContainerStyleSelector="{StaticResource tviSelector}">

      <!--Display the TopLevelName property in the first level.-->
      <TextBlock Text="{Binding Path=TopLevelName}"/>
      
      <!--Display each string in the SecondLevelItems property in
          the second level.-->
      <HierarchicalDataTemplate.ItemTemplate>
          <DataTemplate>
              <TextBlock Text="{Binding}"/>
          </DataTemplate>
      </HierarchicalDataTemplate.ItemTemplate>
      
    </HierarchicalDataTemplate>
  </StackPanel.Resources>

  <TreeView Height="200" ItemsSource="{Binding Source={StaticResource dataItems}}"
            VirtualizingStackPanel.IsVirtualizing="True">
    <TreeView.ItemContainerStyle>

      <!--Expand each TreeViewItem in the first level.-->
      <Style TargetType="TreeViewItem">
        <Setter Property="IsExpanded" Value="True"/>
      </Style>
    </TreeView.ItemContainerStyle>
  </TreeView>
</StackPanel>

En el ejemplo siguiente se muestra el StyleSelector que se usa en el ejemplo anterior.

public class TreeViewItemStyleSelector : StyleSelector
{
    public override Style SelectStyle(object item, DependencyObject container)
    {
        string itemString = item as string;

        string[] strings = itemString.Split(null);
        int value;
        
        if (!Int32.TryParse(strings[strings.Length - 1], out value))
        {
            return null;
        }

        StackPanel sp = ((Window1) Application.Current.MainWindow).sp1;

        if (value < 5)
        {
            return sp.FindResource("TreeViewItemStyle1") as Style;
        }
        else
        {
            return sp.FindResource("TreeViewItemStyle2") as Style;
        }
    }
}

Public Class TreeViewItemStyleSelector
    Inherits StyleSelector
    Public Overloads Overrides Function SelectStyle(ByVal item As Object, ByVal container As DependencyObject) As Style
        Dim itemString As String = TryCast(item, String)

        Dim strings As String() = itemString.Split(Nothing)
        Dim value As Integer

        If Not Int32.TryParse(strings(strings.Length - 1), value) Then
            Return Nothing
        End If

        Dim win1 As Window1 = CType(Application.Current.MainWindow, Window1)
        Dim sp As StackPanel = win1.sp1

        If value < 5 Then
            Return TryCast(sp.FindResource("TreeViewItemStyle1"), Style)
        Else
            Return TryCast(sp.FindResource("TreeViewItemStyle2"), Style)
        End If

    End Function
End Class

En el ejemplo siguiente se crean los datos que se usan en el ejemplo anterior.

public class TreeViewData : ObservableCollection<ItemsForTreeView>
{

    public TreeViewData()
    {
        for (int i = 0; i < 100; ++i)
        {
            ItemsForTreeView item = new ItemsForTreeView();
            item.TopLevelName = "item " + i.ToString();
            Add(item);
        }
    }
}

public class ItemsForTreeView
{
    public string TopLevelName { get; set; }
    private ObservableCollection<string> level2Items;

    public ObservableCollection<string> SecondLevelItems
    {
        get 
        {
            level2Items ??= new ObservableCollection<string>();
            return level2Items;
        }
    }

    public ItemsForTreeView()
    {
        for (int i = 0; i < 10; ++i)
        {
            SecondLevelItems.Add("Second Level " + i.ToString());
        }
    }
}

Public Class TreeViewData
    Inherits ObservableCollection(Of ItemsForTreeView)

    Public Sub New()
        For i As Integer = 0 To 99
            Dim item As New ItemsForTreeView()
            item.TopLevelName = "item " & i.ToString()
            Add(item)
        Next
    End Sub
End Class


Public Class ItemsForTreeView
    Private _TopLevelName As String
    Public Property TopLevelName() As String
        Get
            Return _TopLevelName
        End Get
        Set(ByVal value As String)
            _TopLevelName = value
        End Set
    End Property
    Private level2Items As ObservableCollection(Of String)

    Public ReadOnly Property SecondLevelItems() As ObservableCollection(Of String)
        Get
            If level2Items Is Nothing Then
                level2Items = New ObservableCollection(Of String)()
            End If
            Return level2Items
        End Get
    End Property

    Public Sub New()
        For i As Integer = 0 To 9
            SecondLevelItems.Add("Second Level " & i.ToString())
        Next
    End Sub
End Class

Comentarios

La propiedad se usa ItemContainerStyle para establecer un estilo para afectar a la apariencia de los elementos que contienen los elementos de datos. Por ejemplo, para TreeView, los contenedores generados son TreeViewItem controles; para Menu, son MenuItem controles. Si tiene más de un estilo definido y necesita proporcionar lógica para elegir cuál se va a aplicar, use la ItemContainerStyleSelector propiedad en lugar de la ItemContainerStyle propiedad . Tenga en cuenta que esta propiedad se omite si ItemContainerStyle la propiedad está establecida.

Se aplica a