DevExpress XtraGrid 主从表时， 关于从表新增的问题

public class StaticUnitParameter1 : StaticUnitType
    {
        public List<StaticUnitProcItem> staticUnitProcItem { get; set; }

        public StaticUnitParameter1()
        {
            staticUnitProcItem = new List<StaticUnitProcItem>();
        }
}
public class StaticUnitParameter1 : StaticU