ItemsControl.GroupStyle Property

Gets a collection of GroupStyle objects that define the appearance of each level of groups.

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

public ObservableCollection<GroupStyle> GroupStyle { get; }
<object>
  <object.GroupStyle>
    OneOrMoreGroupStyleObjects
  </object.GroupStyle>
</object>

XAML Values

OneOrMoreGroupStyleObjects

One or more GroupStyle objects.

Property Value

Type: System.Collections.ObjectModel.ObservableCollection<GroupStyle>
A collection of GroupStyle objects that define the appearance of each level of groups.

The entry at index 0 describes the top-level groups, the entry at index 1 describes the next level, and so on. If there are more levels of grouping than entries in the collection, the last entry is used for the extra levels.

The following examples show an ItemsControl that is bound to an XmlDataProvider and the code-behind content that contains the logic to add and remove grouping. When the check box is checked, the content of the ItemsControl is grouped by the Type attribute.

Each group is of type CollectionViewGroup. The GroupStyle HeaderTemplate is specified so that it appears as a TextBlock that displays the Name of each the group. In this case, the Name is either Work or Home.

<Window x:Class="GroupingSample.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Grouping Sample"
    Width="220" Height="550">
  <StackPanel>

    <StackPanel.Resources>
      <XmlDataProvider x:Key="myTasks" XPath="Tasks/Task">
        <x:XData>
          <Tasks xmlns="">
            <Task Name="Groceries" Priority="2" Type="Home">
              <Description>Pick up Groceries and Detergent</Description>
            </Task>
            <Task Name="Laundry" Priority="2" Type="Home">
              <Description>Do Laundry</Description>
            </Task>
            <Task Name="Email" Priority="1" Type="Work">
              <Description>Email Clients</Description>
            </Task>
            <Task Name="Clean" Priority="3" Type="Work">
              <Description>Clean my office</Description>
            </Task>
            <Task Name="Dinner" Priority="1" Type="Home">
              <Description>Get ready for family reunion</Description>
            </Task>
            <Task Name="Proposals" Priority="2" Type="Work">
              <Description>Review new budget proposals</Description>
            </Task>
          </Tasks>
        </x:XData>
      </XmlDataProvider>
    </StackPanel.Resources>

    <TextBlock Margin="12,5,5,0" FontSize="20" Text="My Task List"/>
    <CheckBox Margin="10,5,5,10" Checked="AddGrouping"
              Unchecked="RemoveGrouping">Group by task type</CheckBox>
    <ItemsControl Margin="10" Name="myItemsControl"
                  ItemsSource="{Binding Source={StaticResource myTasks}}">
      <ItemsControl.ItemTemplate>
        <DataTemplate>
          <DataTemplate.Resources>
            <Style TargetType="TextBlock">
              <Setter Property="FontSize" Value="18"/>
              <Setter Property="HorizontalAlignment" Value="Center"/>
            </Style>
          </DataTemplate.Resources>
          <Grid>
            <Ellipse Fill="Silver"/>
            <StackPanel>
              <TextBlock Margin="3,3,3,0"
                         Text="{Binding XPath=@Name}"/>
              <TextBlock Margin="3,0,3,7"
                         Text="{Binding XPath=@Priority}"/>
            </StackPanel>
          </Grid>
        </DataTemplate>
      </ItemsControl.ItemTemplate>
      <ItemsControl.ItemContainerStyle>
        <Style>
          <Setter Property="Control.Width" Value="100"/>
          <Setter Property="Control.Margin" Value="5"/>
        </Style>
      </ItemsControl.ItemContainerStyle>
      <ItemsControl.GroupStyle>
        <GroupStyle>
          <GroupStyle.HeaderTemplate>
            <DataTemplate>
              <TextBlock FontWeight="Bold" FontSize="15"
                         Text="{Binding Path=Name}"/>
            </DataTemplate>
          </GroupStyle.HeaderTemplate>
        </GroupStyle>
      </ItemsControl.GroupStyle>
    </ItemsControl>
  </StackPanel>
</Window>
using System;
using System.Windows;
using System.Windows.Data;

namespace GroupingSample
{
    public partial class Window1 : System.Windows.Window
    {

        public Window1()
        {
            InitializeComponent();
        }

        CollectionView myView;
        private void AddGrouping(object sender, RoutedEventArgs e)
        {
            myView = (CollectionView)CollectionViewSource.GetDefaultView(myItemsControl.ItemsSource);
            if (myView.CanGroup == true)
            {
                PropertyGroupDescription groupDescription
                    = new PropertyGroupDescription("@Type");
                myView.GroupDescriptions.Add(groupDescription);
            }
            else 
                return;
        }

        private void RemoveGrouping(object sender, RoutedEventArgs e)
        {
            myView = (CollectionView)CollectionViewSource.GetDefaultView(myItemsControl.ItemsSource);
            myView.GroupDescriptions.Clear();
        }
    }
}

More Code

How to: Group Items in a ListView That Implements a GridViewThis example shows how to display groups of items in the GridView view mode of a ListView control.

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Was this page helpful?
(1500 characters remaining)
Thank you for your feedback
Show:
© 2014 Microsoft