In order to achieve a Master/Detail view in a FeatureDataGrid you need to associate "RowDetailsTemplate" to each row. After setting the "AutoGenerateColumns" property to false set the column colection using something similar to the following code snippets:
xmlns:data="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Data"
<esri:FeatureDataGrid.Columns>
<data:DataGridTextColumn Header="State" Binding="{Binding [STATE]}"/>
...
</esri:FeatureDataGrid.Columns>
And to set "RowDetailsTemplate" do the following:
<esri:FeatureDataGrid.RowDetailsTemplate>
<DataTemplate>
<StackPanel Margin="10">
<StackPanel Orientation="Horizontal">
<TextBlock Text="Number of Households: " FontWeight="Bold" />
<TextBlock Text="{Binding [HOUSEHOLDS]}" Margin="0,5,0,0" />
</StackPanel>
...
</StackPanel>
</DataTemplate>
</esri:FeatureDataGrid.RowDetailsTemplate>
The above code snippets shows you how to show "STATE" attribute of your layer as a column header with an alias name "State". When your row is expanded other attributes such as "HOUSEHOLDS"... will be shown in a specified layout. Also, need to mention that you can optionally set the behavior of showing the detail view using the "RowDetailsVisibilityMode" property, e.g. always visible, visible when selected... Since FeatureDataGrid is an inherited control from Microsoft DataGrid control you get all its functionalities and behaviors and I suggest you to also take a look at the following URL:http://msdn.microsoft.com/en-us/library/system.windows.controls.datagrid.rowdetailstemplate(VS.95).a... Hope you'll get the idea 🙂
