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.NET Framework Class Library
StyleSelector Class

Provides a way to apply styles based on custom logic.

Inheritance Hierarchy
SystemObject
  System.Windows.ControlsStyleSelector

Namespace:   System.Windows.Controls
Assembly:  PresentationFramework (in PresentationFramework.dll)
XMLNS for XAML: http://schemas.microsoft.com/winfx/2006/xaml/presentation, http://schemas.microsoft.com/netfx/2007/xaml/presentation
Syntax
Public Class StyleSelector
public class StyleSelector
public ref class StyleSelector
type StyleSelector =  class end
public class StyleSelector
<StyleSelector .../>

The StyleSelector type exposes the following members.

Constructors
  NameDescription
Public method StyleSelectorInitializes a new instance of a StyleSelector.
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Methods
  NameDescription
Public method Equals(Object)Determines whether the specified object is equal to the current object. (Inherited from Object.)
Protected method FinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public method GetHashCodeServes as the default hash function. (Inherited from Object.)
Public method GetTypeGets the Type of the current instance. (Inherited from Object.)
Protected method MemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public method SelectStyleWhen overridden in a derived class, returns a Style based on custom logic.
Public method ToStringReturns a string that represents the current object. (Inherited from Object.)
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Remarks

To create a StyleSelector that applies a style based on custom logic, create a subclass of the StyleSelector class and implement the SelectStyle method.

Examples

The following example shows how to define a StyleSelector that defines a Style for a row. This example defines the Background color according to the row index.

	Public Class ListViewItemStyleSelector
		Inherits StyleSelector
		Public Overrides Function SelectStyle(ByVal item As Object, ByVal container As DependencyObject) As Style
			Dim st As New Style()
			st.TargetType = GetType(ListViewItem)
			Dim backGroundSetter As New Setter()
			backGroundSetter.Property = ListViewItem.BackgroundProperty
			Dim listView As ListView = TryCast(ItemsControl.ItemsControlFromItemContainer(container), ListView)
			Dim index As Integer = listView.ItemContainerGenerator.IndexFromContainer(container)
			If index Mod 2 = 0 Then
				backGroundSetter.Value = Brushes.LightBlue
			Else
				backGroundSetter.Value = Brushes.Beige
			End If
			st.Setters.Add(backGroundSetter)
			Return st
		End Function
	End Class
public class ListViewItemStyleSelector : StyleSelector
{
    public override Style SelectStyle(object item, 
        DependencyObject container)
    {
        Style st = new Style();
        st.TargetType = typeof(ListViewItem);
        Setter backGroundSetter = new Setter();
        backGroundSetter.Property = ListViewItem.BackgroundProperty;
        ListView listView = 
            ItemsControl.ItemsControlFromItemContainer(container) 
              as ListView;
        int index = 
            listView.ItemContainerGenerator.IndexFromContainer(container);
        if (index % 2 == 0)
        {
            backGroundSetter.Value = Brushes.LightBlue;
        }
        else
        {
            backGroundSetter.Value = Brushes.Beige;
        }
        st.Setters.Add(backGroundSetter);
        return st;
    }
}    

The following example shows how to define a ResourceKey for the StyleSelector. The namespc prefix maps to a CLR namespace and the corresponding assembly where the StyleSelector is defined. For more information, see XAML Namespaces and Namespace Mapping for WPF XAML.

<namespc:ListViewItemStyleSelector x:Key="myStyleSelector"/>

The following example shows how to set the ItemContainerStyleSelector property of a ListView to this StyleSelector resource.

<ListView 
      ItemsSource="{Binding Source={StaticResource EmployeeData}, 
                                        XPath=Employee}"
      ItemContainerStyleSelector="{DynamicResource myStyleSelector}" >      
  <ListView.View>
    <GridView>
      <GridViewColumn DisplayMemberBinding="{Binding XPath=FirstName}" 
                      Header="First Name" Width="120"/>
      <GridViewColumn DisplayMemberBinding="{Binding XPath=LastName}" 
                      Header="Last Name" Width="120"/>
      <GridViewColumn DisplayMemberBinding="{Binding XPath=FavoriteCity}" 
                      Header="Favorite City" Width="120"/>
    </GridView>
  </ListView.View>
</ListView>

For an example of how to create a selector to choose a defined style resource, see the implementation of DataTemplateSelectorSelectTemplate, which allows you to use custom logic to select a DataTemplate, based on a similar concept.

Version Information

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1
Thread Safety
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.