编写一个通用递归获取树形结构对象集合的方法

        /// <summary>
        /// 通用递归获取树状子节点信息
        /// </summary>
        /// <param name="item"></param>
        /// <param name="id"></param>
        /// <returns></returns>
        private List<T> getTreeListByPid<T, F>(List<F> item, long pid, F d) where T : BaseTreeDto<T>, new() where F : BaseTreeDic, new()
        {
            List<T> ItemsDto = new List<T>();
            //限制条件跳出
            if (item.Where(s => s.Pid == pid).Count() > 0)
            {
                item.Where(s => s.Pid == pid).ToList().ForEach(f =>
                {
                    ItemsDto.Add(new T { Id = f.Id, Name = f.Name, Item = getTreeListByPid<T, F>(item, f.Id, f) });
                });
            }
            return ItemsDto;
        }

    public class BaseTreeDto<T>
    {
        public long Id { get; set; }
        public string Name { get; set; }
        public List<T> Item { get; set; }
    }

    public class BaseTreeDic
    {
        public long Id { get; set; }
        public string Name { get; set; }
        public string Code { get; set; }
        public long Pid { get; set; }
    }

 调用方式 将头节点筛选出来然后传参进入方法即可（以下是伪代码）

           
            List<T> list = new List<T>();
            List<F> item = GetListF();
            List<F> tempAllitem = item.Where(i => i.Pid == 0).ToList();
            tempAllitem.ForEach(i =>
            {
                list.Add(new T{ Id = i.Id, Name = i.Name, Item = getTreeListByPid<T, F>(item, i.Id, i) });
            });