Hi,

I don't know why you insist on using CellClickAction="SelectRecord"  in your  application.
In answer to your question - "How can I get the selected cell index from ActiveRecord ?"
I suggest you the following.

In the Xaml file use this:  
 

<Grid>
        <igDP:XamDataGrid Name="xamDataGrid1" BindToSampleData="True"  Margin="0,0,0,144"  SelectedItemsChanged="xamDataGrid1_SelectedItemsChanged">
           <igDP:XamDataGrid.FieldSettings>
                  <igDP:FieldSettings
                      CellClickAction="SelectCell"
                      AllowEdit="False"/>
           </igDP:XamDataGrid.FieldSettings>
      </igDP:XamDataGrid>
</Grid>

In the code behind use this:

private void xamDataGrid1_SelectedItemsChanged(object sender, Infragistics.Windows.DataPresenter.Events.SelectedItemsChangedEventArgs e)
    {
       DataRecord selectedRecord = (DataRecord) xamDataGrid1.ActiveRecord;
       Cell selectedCell = xamDataGrid1.ActiveCell;
       CellCollection cellCollection = selectedRecord.Cells;
       int indxSelectedCell = cellCollection.IndexOf(selectedCell);
       MessageBox.Show("The index of the selected cell is :" + indxSelectedCell.ToString());
    }

Best Regards,

Yanko