DataTable,List去重复记录的方法

来源：互联网发布：除了淘宝还有什么平台编辑：程序博客网时间：2024/04/30 09:28

转载自:菩提树下的杨过 http://yjmyzz.cnblogs.com/

using System.Collections.Generic;
using System.Linq;
using System.Data;
using System;

namespace ConsoleApplication2
{
    class Program
    {
        static void Main(string[] args)
        {
            DataTable tbl = new DataTable();
            tbl.Columns.Add("Id", typeof(System.Int32));
            tbl.Columns.Add("City", typeof(System.String));
            tbl.Columns.Add("Province", typeof(System.String));

            tbl.Rows.Add(1, "武汉", "湖北");
            tbl.Rows.Add(2, "应城", "湖北");
            tbl.Rows.Add(3, "武汉", "湖北");

            IEnumerable <DataRow> r = tbl.AsEnumerable().Distinct(new CityComparer());



            //到这一步,r里就是去重复的记录了

            foreach (var item in r)
            {
                Console.WriteLine(item["Id"] + "，" + item["City"] + "，" + item["Province"]);
            }

            Console.ReadLine();
        }


    }

    class CityComparer : IEqualityComparer <DataRow>
    {
        public bool Equals(DataRow r1, DataRow r2)
        {
            return r1["City"] == r2["City"];
        }

        public int GetHashCode(DataRow obj)
        {
            return obj.ToString().GetHashCode();
        }

    }
}