You can try code like:
GridCurrentCell cc = this.gridGroupingControl1.TableControl.CurrentCell;
GridTableCellStyleInfo style = this.gridGroupingControl1.TableControl.GetTableViewStyleInfo(cc.RowIndex, cc.ColIndex);
GridRecordRow recRow = style.TableCellIdentity.DisplayElement as GridRecordRow;
if(recRow != null)
{
DataRowView drv = recRow.ParentRecord.GetData() as DataRowView;
if(drv != null)
{
drv["Col1"] = "aaaa";
this.gridGroupingControl1.CurrencyManager.EndCurrentEdit();
}
}