递归一个List，可自己根据需要改造为通用型。

递归方法

    public class ProvinceOrg : ICloneable
    {
        public int orgId { get; set; }
        public int parentOrgId { get; set; }
        public int areaId { get; set; }
        public string areaCode { get; set; }
        public string orgName { get; set; }
        public string fullOrgName { get; set; }
        public List<ProvinceOrg> children { get; set; }

        /// <summary>
        /// 克隆并返回一个对象。
        /// </summary>
        /// <returns></returns>
        public ProvinceOrg Clone()
        {
            ProvinceOrg p = (ProvinceOrg)this.MemberwiseClone();
            p.children = new List<ProvinceOrg>();
            return p;
        }

        object ICloneable.Clone()
        {
            return this.Clone();
        }
    }

实体类

    public class ProvinceOrg : ICloneable
    {
        public int orgId { get; set; }
        public int parentOrgId { get; set; }
        public int areaId { get; set; }
        public string areaCode { get; set; }
        public string orgName { get; set; }
        public string fullOrgName { get; set; }
        public List<ProvinceOrg> children { get; set; }

        /// <summary>
        /// 克隆并返回一个对象。
        /// </summary>
        /// <returns></returns>
        public ProvinceOrg Clone()
        {
            ProvinceOrg p = (ProvinceOrg)this.MemberwiseClone();
            p.children = new List<ProvinceOrg>();
            return p;
        }

        object ICloneable.Clone()
        {
            return this.Clone();
        }
    }