c# 敏捷2 ForEach ToDictionary ToLookup Except比较

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

namespace ConsoleApplication2
{
   
    class Program
    {
        public  class post
        {
            public string id { get; set; }
            public string name { get; set; }
            public int age { get; set; }
            public string pd { get; set; }
        }
        static void Main(string[] args)
        {
            var product = new List<post>
          {
                new post { name="123"},
                new post { name="124"},
                new post { name="125"},
                new post { name="126"},
          };
            product.ToList().ForEach(a => a.id = Guid.NewGuid().ToString("N"));//进行遍历赋值

            var pp = product.ToDictionary(a => a.name, a => a.id); //转成字典
            Console.WriteLine(pp.FirstOrDefault().Key + " " + pp.FirstOrDefault().Value);

            product.Add(new post { name = "123", id = Guid.NewGuid().ToString("N") });
            var pd = product.ToLookup(a => a.name, a => a.id);//groupby之后转成字典，取不同项
            Console.WriteLine(pp.FirstOrDefault().Key + " " + pp.FirstOrDefault().Value);

            var pro = new List<post>
          {
                new post { id = Guid.NewGuid().ToString("N"),name="123",age=1,pd="sad"},
                new post { id = Guid.NewGuid().ToString("N"),name="124",age=11,pd="sad"},
                new post { id = Guid.NewGuid().ToString("N"),name="125",age=111,pd="sad"},
                new post {id = Guid.NewGuid().ToString("N"), name="126",age=1111,pd="sad"},
          };
            var prd = new List<post>
          {
                new post { id = Guid.NewGuid().ToString("N"),name="123",age=1,pd="sad"},
                new post { id = Guid.NewGuid().ToString("N"),name="124",age=11,pd="sad"},
                new post {id = Guid.NewGuid().ToString("N"), name="1245",age=111,pd="sad"},
                new post {id = Guid.NewGuid().ToString("N"), name="126",age=1111,pd="sad"},
          };
            var dsz = pro.Select(s => new { id = s.age, name = s.name, pd = s.pd });
            var dsx = prd.Select(s => new { id = s.age, name = s.name, pd = s.pd });
            var dsc = dsz.Except(dsx).Count();
            if (dsc > 0)
                Console.WriteLine("修改过");
            else
                Console.WriteLine("未修改");

            if (pro.Select(s => new { id = s.age, name = s.name, pd = s.pd }).Except(prd.Select(s => new { id = s.age, name = s.name, pd = s.pd })).Count() > 0)
                Console.WriteLine("修改过");
            else
                Console.WriteLine("未修改");
            Console.WriteLine(dsc);
            
            Console.Read();

        }

    }



}