DataTableGrouping
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Shows how you can group data in a C1.Silverlight.Data.DataTable object.

The C1.Silverlight.Data.DataTable class is similar to the DataTable class
in the System.Data namespace, which is not available in Silverlight.

Like the traditional DataTable class, the C1.Silverlight.Data.DataTable 
contains a Rows collection that contains the data in arbitrary order,
and a DefaultView property that exposes a sorted, filtered view of the 
data. The DefaultView property is used in binding scenarios.

In addition to sorting and filtering, the DefaultView implemented by 
the C1.Silverlight.Data.DataTable also supports grouping. For example,
the code below is used in the sample to group data by country and product:

<code>
	// add grouping to the table's default view
    var gd = dataTable.DefaultView.GroupDescriptions;
    gd.Add(new PropertyGroupDescription("Country"));
    gd.Add(new PropertyGroupDescription("Product"));
</code>

The groups are automatically shown when the DefaultView is used as the
ItemsSource for any control that supports grouped views (including the
C1DataGrid and the C1FlexGrid for example).

Another option would be to create a PagedCollectionView object using the 
DataTable's DefaultView as the parameter in the constructor. You could 
then apply sorting, grouping, and filtering directly to the PagedCollectionView 
and not even program against the DataTable. 
