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.net,c#,List,Lambda按某列排除重复

//.net,c#,List,Lambda 排除重复直接看代码： 
     
//场景1,有以下的数据，现要按name列排除重复,使name列唯一
List<Model> li1 = new List<Model>()
{
    new Model { id = "1111", name = "name1", gender=20 },
    new Model { id = "2222", name = "name2", gender = 21 },
    new Model { id = "3333", name = "name1", gender = 22 },
    new Model { id = "4444", name = "name2", gender = 23 },
    new Model { id = "5555", name = "name5", gender = 25 },
};
//场景2，有以下的数据，现要把每行完全一样的去掉，使数据唯一
List<Model> li2 = new List<Model>()
{
    new Model { id = "1111", name = "name1", gender = 20 },
    new Model { id = "1111", name = "name1", gender = 20 },
    new Model { id = "2222", name = "name1", gender = 20 },
    new Model { id = "1111", name = "nnnn1", gender = 20 },
    new Model { id = "1111", name = "name1", gender = 22 },
};
     
/* 1.
 * 排除重复后只输出单列,结果:
 * name = "name1";name = "name2";name = "name5"
 */
var ol = li1.GroupBy(p => p.name).Distinct();//
     
/*2.
 * name列不重复
 * 排除重复后输出多列.结果: 
 * id = "1111", name = "name1",gender=20 
 * id = "2222", name = "name2",gender=21
 * id = "5555", name = "name5",gender=25
 */
     
var ol2 = li1.GroupBy(p => p.name).Select(p => p.First());
     
/*3.
 * name列不重复
 * 排除重复后.选择输出id,gender两列.结果: 
 * id = "1111",gender=20 
 * id = "2222",gender=21
 * id = "5555",gender=25
 */
var ol3 = li1.GroupBy(p => p.name).Select(p => p.First()).Select(p => new { p.id,p.gender });//
     
foreach (var item in ol)
{
    Response.Write(item.Key + "|");//1111,name1,20|2222,name2,21|5555,name5,25| 
}
     
Response.Write("<hr/>");
     
foreach (var item in ol2)
{
    Response.Write(item.id + "," + item.name + "," + item.gender + "|");//1111 name1|2222 name2|5555 name5| 
     
}
   
//场景2的排除法
var ol4 = li2.GroupBy(p => new { p.name,p.id,p.gender }).Select(p => p.First());
   
//model
public class Model
{
    public string id { get; set; }
    public string name { get; set; }
    public int gender { get; set; }
}

类别：DotNET   阅读(0)   评论(0)    发表时间：2013-01-17 20:12  星期四