c# get，set设置默认值

        public virtual string SplitPlateType
        {
            get
            {
                if (SplitPlateType == null)
                {
                    return "默认值";
                }
                else
                {
                    return SplitPlateType;
                }  
            }
           set { SplitPlateType = value; } 
        }