C#树结构操作逻辑整理

来源：互联网发布：希尔薇知乎编辑：程序博客网时间：2024/05/16 00:39

1.向下查询

        /// <summary>        /// --1.指定ID ，向下查询所有的子节点------递归获取        /// </summary>        /// <param name="id"></param>        public List<Tree> getChild(int id)        {            List<Tree> list = new List<Tree>();            //根据NodeID，获取当前子节点列表            List<Tree> chidList = _Context.Trees.Where(q => q.ParentID == id).ToList();            if (chidList.Count > 0)            {                //获取下一级                list.AddRange(chidList);                foreach (var item in chidList)                {                    //递归获取下一级                    chidList = getChild(item.NodeID);                    list.AddRange(chidList);                }            }            return list;        }        /// <summary>        /// --1.指定ID ，向下查询所有的子节点----死循环获取        /// </summary>        /// <param name="id"></param>        public List<Tree> getChild2(int id)        {            List<Tree> list = new List<Tree>();            List<int> idList = new List<int>() { id };            while (true)            {                //1.获取子节点列表                List<Tree> childList = _Context.Trees.Where(q => idList.Contains(q.ParentID)).ToList();                if (childList.Count <= 0)                    break;                list.AddRange(childList);                //2.遍历子节点 ID列表                idList = childList.Select(q => q.NodeID).ToList();                if (idList.Count <= 0)                    break;            }            return list;        }

2.向上查询

        /// <summary>        /// --2.指定ID，向上查询所有的父级节点----递归获取        /// </summary>        public List<Tree> getParent(int id)        {            List<Tree> list = new List<Tree>();            //获取当前项            Tree tree = _Context.Trees.Where(q => q.NodeID == id).FirstOrDefault();            if (tree != null)            {                //获取上一级                Tree parent = _Context.Trees.Where(q => q.NodeID == tree.ParentID).FirstOrDefault();                if (parent != null)                {                    list.Add(parent);                    //递归调用 获取上一级                    list.AddRange(getParent(parent.NodeID));                }            }            return list;        }        /// <summary>        /// --2.指定ID，向上查询所有的父级节点----死循环获取        /// </summary>        public List<Tree> getParent2(int id)        {            List<Tree> list = new List<Tree>();            while (true)            {                //1.获取当前项                Tree tree = _Context.Trees.Find(id);                if (tree == null)                    break;                //2.修改下一次获取上一级                list.Add(tree);                id = tree.ParentID;            }            return list;        }

3.获取其他同级节点

        /// <summary>        /// --3，指定ID，获取其他同级节点        /// </summary>        public List<Tree> getSiblings(int id)        {            List<Tree> list = new List<Tree>();            //1.获取当前项的上级ID            Tree tree = _Context.Trees.Find(id);            if (tree != null)            {                //2.获取上一级下的所有节点，过滤掉自己                list.AddRange(_Context.Trees.Where(q => q.ParentID == tree.ParentID && q.NodeID != id));            }            return list;        }

4.是否是子节点

        /// <summary>        /// --3.指定ParentID，判断TargetID，是否是子节点        /// </summary>        public bool isChild(int parentID, int targetID)        {            //1.过滤 相同情况            if (parentID == targetID) return false;            List<int> idList = new List<int>() { parentID };            while (true)            {                //2.获取子节点列表                List<Tree> childList = _Context.Trees.Where(q => idList.Contains(q.ParentID)).ToList();                if (childList.Count <= 0)                    return false;                //3.判断是否是子节点                if (childList.Any(q => q.NodeID == targetID))                    return true;                //4.重置子节点ID 列表                idList = childList.Select(q => q.NodeID).ToList();            }        }

5.是否是父节点

        /// <summary>        /// --4.指定ChildID，判断TargetID，是否是父节点        /// </summary>        public bool isParent(int childID, int targetID)        {            //1.过滤相同情况            if (childID == targetID) return false;            while (true)            {                //1.获取当前项                 Tree tree = _Context.Trees.Find(childID);                if (tree == null)                    return false;                //2.判断是否是父节点                if (tree.ParentID == targetID)                    return true;                //3.重置字节ID                childID = tree.ParentID;            }        }

0 0