'Declaration Public ReadOnly Property AvailableFieldLabels As GroupByAreaFieldLabelCollection
public GroupByAreaFieldLabelCollection AvailableFieldLabels {get;}
This collection is automatically populated with GroupByAreaFieldLabels for each un-grouped field in the DefaultFieldLayout
The GroupByAreaFieldLabels in this collection are derived from System.Windows.Controls.Primitives.Thumb and represent Fields available for grouping. The default style for the GroupByArea contains a System.Windows.Controls.ListBox which is bound to this collection. Since the elements in the collection are derived from System.Windows.Controls.Primitives.Thumb they automatically support drag and drop. When the GroupByArea creates these elements it listens to the drag events and automatically groups/ungroups the field represented by the GroupByAreaFieldLabel being dragged and manages the contents of the AvailableFieldLabels and GroupedFieldLabels collections.
If you replace the Template for the GroupByArea you can bind to this collection to take advantage of this same functionality.
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, 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