DataTable,List去重复记录的方法（转载）

DataTable,List去重复记录的方法

思路：将DataTable转成IEnumerable，然后就能调用Distinct方法了

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(); 
        } 


    } 
}