Condividi tramite


How to: Alternate the Background Color for Rows in a ListView

This example shows three methods that you can use to alternate the Background color for rows in a ListView.

Example

The following sections provide three methods to create a ListView with rows that alternate in Background color. The example also discusses a method for updating the view when you add or remove rows.

Method 1: Define a Style That Uses an IValueConverter to Alternate Background Color

The following example shows how to define a Style for a ListViewItem control that binds the value of the Background property to an IValueConverter.

<Style x:Key="myItemStyle" TargetType="{x:Type ListViewItem}">
  <Setter Property="Background">
    <Setter.Value>
      <Binding RelativeSource="{RelativeSource Self}" 
               Converter="{StaticResource myConverter}"/>
    </Setter.Value>
  </Setter>
</Style>

The following example defines a ResourceKey for the IValueConverter.

<namespc:BackgroundConverter x:Key="myConverter"/>

The following example shows the definition of the IValueConverter that sets the Background property according to the row index.

public sealed class BackgroundConverter : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, 
        CultureInfo culture)
    {
        ListViewItem item = (ListViewItem)value;
        ListView listView = 
            ItemsControl.ItemsControlFromItemContainer(item) as ListView;
        // Get the index of a ListViewItem
        int index = 
            listView.ItemContainerGenerator.IndexFromContainer(item);

        if (index % 2 == 0)
        {
            return Brushes.LightBlue;
        }
        else
        {
            return Brushes.Beige;
        }
    }

The following example shows how to define a ListView that uses Style as its ItemContainerStyle in order to provide the required layout.

<ListView Name="theListView" 
          ItemsSource="{Binding Source={StaticResource EmployeeData}, 
                                        XPath=Employee}"
          ItemContainerStyle="{StaticResource myItemStyle}" >
  <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>

Method 2: Derive a New Class from ListView to Alternate Background Color

The following example shows how to define a class that derives from ListView. This class overrides the PrepareContainerForItemOverride method in order to create rows that have alternating Background colors.

public class SubListView : ListView
{
    protected override void
        PrepareContainerForItemOverride(DependencyObject element,
        object item)
    {
        base.PrepareContainerForItemOverride(element, item);
        if (View is GridView)
        {
            int index = ItemContainerGenerator.IndexFromContainer(element);
            ListViewItem lvi = element as ListViewItem;
            if (index % 2 == 0)
            {
                lvi.Background = Brushes.LightBlue;
            }
            else
            {
                lvi.Background = Brushes.Beige;
            }
        }
    }
}

The following example shows how to create an instance of this class. The namespc prefix maps to a common language runtime (CLR) namespace and the corresponding assembly where the StyleSelector is defined.

<namespc:SubListView
      ItemsSource="{Binding Source={StaticResource EmployeeData}, 
                                        XPath=Employee}">
  <namespc:SubListView.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>
  </namespc:SubListView.View>
</namespc:SubListView>

Method 3: Use a StyleSelector to Alternate Background Color

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 : 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.

<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>

Update the ListView After a Change in the ListViewItem Collection

If you add or remove a ListViewItem from a ListView control, you must update the ListViewItem controls in order to recreate the alternating Background color. The following example shows how to update the ListViewItem controls.

ICollectionView dataView =
  CollectionViewSource.GetDefaultView(theListView.ItemsSource);
dataView.Refresh();

See Also

Reference

GridView
ListView

Concepts

ListView Overview
GridView Overview

Other Resources

ListView Samples
ListView How-to Topics