LINQ中Aggregate的用法

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;

 namespace LinqDemo
 {
     class Program
     {
         static void Main(string[] args)
         {
             List<TypeEnum> lstTypeEnum = new List<TypeEnum>() { TypeEnum.A,TypeEnum.B,TypeEnum.C };

             var lstType = lstTypeEnum.Aggregate(new List<int>(),
                 (total,next) =>
                 {
                     total.Add(((int)next));
                     return total;
                 }
             );

             Console.WriteLine(string.Join(",", lstType.ToArray()));//输出1,2,3
             Console.ReadKey();
         }
     }
     public enum TypeEnum
     {
         A = ,B = ,C=
     }
 }