The new xamDataGrid supports IsSynchronizedWithCurrentItem, but I didn't have a way to communicate multiple selections to my view model.

After piecing several forum posts together, I came up with this:

- Add an IsSelected property to your item view model:

public bool IsSelected { get; set; }

- Bind the DataRecordPresenter's IsSelected to your property:

<igDP:XamDataGrid.Resources>

<Style TargetType="{x:Type igDP:DataRecordPresenter}">

<Setter Property="IsSelected" Value="{Binding DataItem.IsSelected, Mode=TwoWay}"/>

</Style>

</igDP:XamDataGrid.Resources>

Now you can check your view models to see which ones are selected.