DataGrid Row Background Color change programmatically

How to change selected row color dynamically in silverlight datagrid. I was trying this code but its notworking...

SampleConverter

bgConverter = new SampleConverter();

           

Binding binding = new Binding("IsChecked") { Mode = BindingMode.TwoWay, Converter = bgConverter, ValidatesOnExceptions = true };

           

DataGridRow objRow = GetDataGridRowByDataContext(dg, dg.SelectedItem);

           

if (objRow != null && objRow.IsValid)

            {

                objRow.SetBinding(

DataGridRow.BackgroundProperty, binding);

                objRow.UpdateLayout();

                dg.UpdateLayout();

            }