init commit

20220330_Vote/Ewide.Core/Util/TreeBuildUtil.cs

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+using System;
+using System.Collections;
+using System.Collections.Generic;
+
+namespace Ewide.Core
+{
+    /// <summary>
+    /// 树基类
+    /// </summary>
+    public interface ITreeNode
+    {
+        /// <summary>
+        /// 获取节点id
+        /// </summary>
+        /// <returns></returns>
+        string GetId();
+
+        /// <summary>
+        /// 获取节点父id
+        /// </summary>
+        /// <returns></returns>
+        string GetPid();
+
+        /// <summary>
+        /// 设置Children
+        /// </summary>
+        /// <param name="children"></param>
+        void SetChildren(IList children);
+    }
+    public class TreeBuildSetting
+    {
+        public bool AddEmptyChildren { get; set; } = true;
+    }
+
+    /// <summary>
+    /// 递归工具类，用于遍历有父子关系的节点，例如菜单树，字典树等等
+    /// </summary>
+    /// <typeparam name="T"></typeparam>
+    public class TreeBuildUtil<T> where T : ITreeNode
+    {
+        TreeBuildSetting _setting;
+        public TreeBuildUtil(TreeBuildSetting setting = null)
+        {
+            _setting = setting ?? new TreeBuildSetting();
+        }
+        /// <summary>
+        /// 顶级节点的父节点Id(默认0)
+        /// </summary>
+        private readonly List<string> _rootParentIds = new List<string> { string.Empty, Guid.Empty.ToString() };
+
+        /// <summary>
+        /// 构造树节点
+        /// </summary>
+        /// <param name="nodes"></param>
+        /// <returns></returns>
+        public List<T> DoTreeBuild(List<T> nodes)
+        {
+            nodes.ForEach(u => BuildChildNodes(nodes, u, new List<T>()));
+
+            var results = new List<T>();
+            nodes.ForEach(u =>
+            {
+                if (_rootParentIds.Contains(u.GetPid()))
+                    results.Add(u);
+            });
+
+            // 在未获取到根节点的情况下, 直接将最上级作为根节点
+            if (results.Count < 1)
+            {
+                var ids = new List<string>();
+                nodes.ForEach(u =>
+                {
+                    ids.Add(u.GetId());
+                });
+
+                nodes.ForEach(u =>
+                {
+                    if (!ids.Contains(u.GetPid()))
+                        results.Add(u);
+                });
+            }
+
+            return results;
+        }
+
+        /// <summary>
+        /// 构造子节点集合
+        /// </summary>
+        /// <param name="totalNodes"></param>
+        /// <param name="node"></param>
+        /// <param name="childNodeLists"></param>
+        private void BuildChildNodes(List<T> totalNodes, T node, List<T> childNodeLists)
+        {
+            var nodeSubLists = new List<T>();
+            totalNodes.ForEach(u =>
+            {
+                if (u.GetPid().Equals(node.GetId()))
+                    nodeSubLists.Add(u);
+            });
+            nodeSubLists.ForEach(u => BuildChildNodes(totalNodes, u, new List<T>()));
+            childNodeLists.AddRange(nodeSubLists);
+            if (childNodeLists.Count > 0 || _setting.AddEmptyChildren)
+            {
+                node.SetChildren(childNodeLists);
+            }
+        }
+    }
+}