using System;using System.Collections;using System.Collections.Generic;using System.Linq;using System.Linq.Expressions;using System.Reflection;namespace XHP{    /// 
    ///     /// 
    public class TreeDataHelper
     
       where T:new()    {        public class TreeModelBase        {            public string id { get; set; }            public string text { get; set; }            /// 
      
            /// closed            /// 
            public string state { get; set; }            public List
      
        children { get; set; }        }        /// 
       
        ///         /// 
        /// 
               /// 
               /// 
               /// 
               /// 
               /// 
               /// 
               /// 
       树默认展开级别-1全不展开，0展开所有，1只展开到1级        /// 
               public static List
       
         GetTreeDataFromList
        
         (List
         
           list, Expression
          
           
            > idFieldExp, Expression
            
             
              > textFieldExp, Expression
              
               
                > pidFieldExp, string rootValue, string emptyRootName="==全部==",int expendLevel=1) { Hashtable tb = new Hashtable(); var idProp = typeof(T).GetProperty(((MemberExpression)idFieldExp.Body).Member.Name); var textProp = typeof(T).GetProperty(((MemberExpression)textFieldExp.Body).Member.Name); var pidProp = typeof(T).GetProperty(((MemberExpression)pidFieldExp.Body).Member.Name); T parent = default(T); if(!string.IsNullOrWhiteSpace(rootValue)) { parent = list.FirstOrDefault(x => idProp.GetValue(x)?.ToString() == rootValue); } TreeModelBase rlt = new TreeModelBase(); if (parent == null) { rlt.id = rootValue??""; rlt.text = emptyRootName; } else { rlt.id = idProp.GetValue(parent).ToString(); rlt.text = textProp.GetValue(parent).ToString(); } rlt.state = expendLevel > -1 ? null : "closed"; var currentLevel = 1; GetTreeDataFromList_SetChild(rlt, list, idProp, textProp, pidProp, expendLevel, currentLevel); return new List
                
                  { rlt } ; } private static void GetTreeDataFromList_SetChild(TreeModelBase parent,List
                 
                   list,PropertyInfo idProp,PropertyInfo textProp, PropertyInfo pidProp, int expendLevel,int currentLevel) { var childs = list.Where(x => (pidProp.GetValue(x)?.ToString() ?? "") == (parent.id ?? "") &&!string.IsNullOrWhiteSpace(idProp.GetValue(x)?.ToString())); if (childs.Count() == 0) { parent.state = null; return; } else { parent.children = new List
                  
                   (); foreach (var item in childs) { var tempChild = new TreeModelBase(); tempChild.id = idProp.GetValue(item).ToString(); tempChild.text = textProp.GetValue(item).ToString(); if (expendLevel == 0) tempChild.state = null; else if (expendLevel == -1) tempChild.state = "closed"; else { tempChild.state = currentLevel < expendLevel ? null : "closed"; } currentLevel++; GetTreeDataFromList_SetChild(tempChild, list, idProp, textProp, pidProp, expendLevel, currentLevel); parent.children.Add(tempChild); } } } }}
                  
                 
                
               
              
             
            
           
          
         
        
       
      
     

　　

今天在用到EasyUI 的Tree，TreeGrid，每次转出这个数据格式非常不爽，就自己写了段HELPER

输出到前端：

JsonConvert.SerializeObject(TreeDataHelper<T>.GetTreeDataFromList(tList, x1 => x1.Id, x1 => x1.Name, x1 => x1.ParentId, "root", "==所有分类==", 0),

new JsonSerializerSettings { NullValueHandling = NullValueHandling.Ignore });