Hi,

Thank you for your post. I have been looking into your requirement and the easiest way to select rows in code-behind is adding the desired rows in the SelectedRows collection of the XamGrid:

            this.xamGrid1.SelectionSettings.SelectedRows.Add(this.xamGrid1.Rows[1]);

            this.xamGrid1.SelectionSettings.SelectedRows.Add(this.xamGrid1.Rows[2]);

            this.xamGrid1.SelectionSettings.SelectedRows.Add(this.xamGrid1.Rows[4]);

For more information you could look into the following link from our online documentation:

http://help.infragistics.com/doc/WPF/2014.1/CLR4.0/?page=xamGrid_Setting_Selection_Programmatically.html

Let me know, if you need any further assistance on this matter.