递归之无限极评论

系统管理员 2022-07-11 02:00 147阅读 0赞

public ActionResult Index()
            {
    
                TestEntities tn = new TestEntities();
    
                List<ly> lylist =  tn.ly.ToList();
    
                //ViewBag.lyparent = lylist.Where(a => a.ParentId == null).ToList();
    
               // ViewBag.alllist = lylist;
    
                List<MyTreeNode> mtn = ParseTree(lylist);
    
                ViewBag.alllist = mtn;
    
                return View();
            }
    
     
     /// <summary>
            /// 解析成一个树的结构
            /// </summary>
            /// <param name="lylist"></param>
            public List<MyTreeNode> ParseTree(List<ly> lylist) 
            {
                List<MyTreeNode> mytn = new List<MyTreeNode>();
    
                //第一步：先把根节点拿到
                foreach (ly item in lylist.Where(a=>a.ParentId==null))
                {
                    MyTreeNode myn = new MyTreeNode();
                    myn.content = item;
    
                    myn.level = 1;
    
                    mytn.Add(myn);
                }
    
                //第二步：为每个子节点找到对应的父亲
                foreach (ly item in lylist.Where(a=>a.ParentId!=null))
                {
                    FindParent(mytn,item);
                }
    
    
                return mytn;
            }
    
            /// <summary>
            /// 为每个子节点找到对应的父亲
            /// </summary>
            /// <param name="_mytn"></param>
            /// <param name="_item"></param>
            public void FindParent(List<MyTreeNode> _mytn, ly _item) 
            {
                foreach (MyTreeNode item in _mytn)
                {
                    if (item.content.Id == _item.ParentId) //表示父亲已经找到了 
                    {
                        if (item.child == null)
                        {
                            item.child = new List<MyTreeNode>();
                        }
    
                        MyTreeNode node = new MyTreeNode();
                        node.content = _item;
    
                        node.level = item.level + 1;
    
                        item.child.Add(node);
    
                        return;
                    }
    
                    //如果该节点还有子节点，继续找
                    if (item.child != null) 
                    {
                        FindParent(item.child, _item);
                    }
    
                }
            }
    
        }
    
        public class MyTreeNode
        {
            public ly content { get; set; }
    
            public int level { get; set; }
    
            public List<MyTreeNode> child { get; set; }
        }
    } 
     
     
     
     前台代码 
     @{
       
        List<MyTreeNode> alllist = ViewBag.alllist as List<MyTreeNode>;
    
        @parseTree(alllist);
    }
    
    
    @helper parseTree(List<MyTreeNode> alllist)
    {
        
        foreach (MyTreeNode item in alllist)
        {
                <div style="margin-left:@(item.level*20)px">@item.content.Content</div>
        
            
        
            if(item.child!=null)
            {
                @parseTree(item.child);
            }
        }
        
     }