PropertyGroupDescription Class

Views support the functionality of grouping, which allows the user to partition the collection in the collection view into logical groups. The groups can be explicit, where the user supplies a list of groups, or implicit, where the groups are generated dynamically depending on the data.

PropertyGroupDescription allows you to create implicit groups based on a PropertyName. If you simply want to group by a property you can set the PropertyName property. If you want to change the value that is eventually used for group you can use the Converter property to supply a value converter. For example, you may want to group items based on the first letter of a name. If the PropertyName property is not set, the item itself is passed to the value converter. The converter may return a collection, which indicates the items can appear in more than one group.

You can also define how string comparison should take place using the StringComparison property.

This example shows how to create a view of a data collection in Extensible Application Markup Language (XAML). Views allow for the functionalities of grouping, sorting, filtering, and the notion of a current item.

In the following example, the static resource named places is defined as a collection of Place objects, in which each Place object is consisted of a city name and the state. The prefix src is mapped to the namespace where the data source Places is defined. The prefix scm maps to "clr-namespace:System.ComponentModel;assembly=WindowsBase" and dat maps to "clr-namespace:System.Windows.Data;assembly=PresentationFramework".

The following example creates a view of the data collection that is sorted by the city name and grouped by the state.

  <Window.Resources>

    <src:Places x:Key="places"/>

    <CollectionViewSource Source="{StaticResource places}" x:Key="cvs">
      <CollectionViewSource.SortDescriptions>
        <scm:SortDescription PropertyName="CityName"/>
      </CollectionViewSource.SortDescriptions>
      <CollectionViewSource.GroupDescriptions>
        <dat:PropertyGroupDescription PropertyName="State"/>
      </CollectionViewSource.GroupDescriptions>
    </CollectionViewSource>

The view can then be a binding source, as in the following example:

<ListBox ItemsSource="{Binding Source={StaticResource cvs}}"
         DisplayMemberPath="CityName" Name="lb">
  <ListBox.GroupStyle>
    <x:Static Member="GroupStyle.Default"/>
  </ListBox.GroupStyle>
</ListBox>

For bindings to XML data defined in an XmlDataProvider resource, precede the XML name with an @ symbol.

<XmlDataProvider x:Key="myTasks" XPath="Tasks/Task">
    <x:XData>
        <Tasks xmlns="">
            <Task Name="Groceries" Priority="2" Type="Home">

<CollectionViewSource x:Key="mySortedTasks"
                      Source="{StaticResource myTasks}">
    <CollectionViewSource.SortDescriptions>
        <scm:SortDescription PropertyName="@Priority" />
    </CollectionViewSource.SortDescriptions>
    <CollectionViewSource.GroupDescriptions>
        <dat:PropertyGroupDescription PropertyName="@Priority" />
    </CollectionViewSource.GroupDescriptions>
</CollectionViewSource>

.NET Framework

.NET Framework Client Profile

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

Other Resources