Php文档 Php问答行业资讯 Php论坛 Php手册 Php博客

游戏榜单

软件榜单

关闭导航

热搜榜

热门下载

热门标签

关闭搜索

php爱好者> php文档>Linq学习笔记(1.8)——Count、Sum、Min、Max、Average

Linq学习笔记(1.8)——Count、Sum、Min、Max、Average

时间：2010-08-20 来源：kis$ove

转：http://www.cnblogs.com/young18/archive/2007/06/05/772843.html

Linq学习笔记(1.8)——Count、Sum、Min、Max、Average

using#region using

using System;

using System.Data;

using System.Configuration;

using System.Linq;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Text;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Web.UI.HtmlControls;

using System.Collections.Generic;

using System.Collections;

#endregion

public partial class _Default : System.Web.UI.Page

{

protected void Page_Load(object sender, EventArgs e)

{

用Count()得出查询结果的个数#region 用Count()得出查询结果的个数

Response.Write("<hr>用Count()得出查询结果的个数<br>");

var langCount = (from s in GetStudents()

select s.Language)

.Distinct()

.Count();

Response.Write(string.Format("<div class='result'>{0}</div>", langCount));

#endregion

用Count()的Lambda表达式满足条件的元素个数#region 用Count()的Lambda表达式满足条件的元素个数

Response.Write("<hr>用Count()得出查询结果的个数<br>");

var ageCoun = (from s in GetStudents()

select s.Age)

.Count(a=>a>22);

Response.Write(string.Format("<div class='result'>{0}</div>", ageCoun));

#endregion

用Sum()将查询结果相加#region 用Sum()将查询结果相加

Response.Write("<hr>用Sum()将查询结果相加<br>");

var ageSum = (from s in GetStudents()

select s.Age)

.Sum();

//var ageSum = GetStudents().Sum(s=>s.Age);

Response.Write(string.Format("<div class='result'>{0}</div>", ageSum));

#endregion

用Min()得出查询结果的最小值#region 用Min()得出查询结果的最小值

Response.Write("<hr>用Min()得出查询结果的最小值<br>");

var ageMin = (from s in GetStudents()

select s.Age)

.Min();

//var ageMin = GetStudents().Min(s => s.Age);

Response.Write(string.Format("<div class='result'>{0}</div>", ageMin));

#endregion

用Max()得出查询结果的最大值#region 用Max()得出查询结果的最大值

Response.Write("<hr>用Max()得出查询结果的最大值<br>");

var ageMax = (from s in GetStudents()

select s.Age)

.Max();

//var ageMax = GetStudents().Max(s => s.Age);

Response.Write(string.Format("<div class='result'>{0}</div>", ageMax));

#endregion

用Average()得出查询结果的平均值#region 用Average()得出查询结果的平均值

Response.Write("<hr>用Average()得出查询结果的平均值<br>");

var ageAverage = (from s in GetStudents()

select s.Age)

.Average();

//var ageAverage = GetStudents().Average(s => s.Age);

Response.Write(string.Format("<div class='result'>{0}</div>", ageAverage));

#endregion

}

构造一个学生集合体#region 构造一个学生集合体

private List<Student> GetStudents()

{

List<Student> students = new List<Student>

{

new Student{ Name="YOUNG", Age=25, Language="Chinese"},

new Student{ Name="JESSIE", Age=21, Language="Scotland"},

new Student{ Name="KELLY", Age=18, Language="English"},

new Student{ Name="JUNE", Age=20, Language="English"},

new Student{ Name="ADRIAN", Age=22, Language="Italy"},

new Student{ Name="BRUCE", Age=17, Language="Scotland"},

new Student{ Name="BRANT", Age=30, Language="Germany"},

new Student{ Name="BEN", Age=25, Language="Chinese"}

};

return students;

}

#endregion

}

学生类#region 学生类

class Student

{

public int Age { get; set; }

public string Name { get; set; }

public string Language { get; set; }

}

#endregion
显示结果