Biegral Blog

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;
            }
        }