Linq学习笔记(1.4)——orderby、Reverse()

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)
    {
        按条件选择后根据指定对象的某个属性排序选择结果#region 按条件选择后根据指定对象的某个属性排序选择结果
        Response.Write("<hr>按条件选择后根据指定对象的某个属性排序选择结果：<br>");
        List<Student> StudentList = GetStudents();
        var students1 = from student in StudentList
                        where student.Age>20
                        orderby student.Age descending //或ascending，默认为ascending
                        select student;

        foreach (var student in students1)
        {
            Response.Write(string.Format("<div class='result'>age:{0}; name:{1}</div>", student.Age, student.Name));
        }
        #endregion 
        
        多个排序条件#region 多个排序条件
        Response.Write("<hr>多个排序条件：<br>");
        var students2 = from student in StudentList
                        orderby student.Language,student.Age descending
                        select student;
        foreach (var student in students2)
        {
            Response.Write(string.Format("<div class='result'>age:{0}; name:{1}; Language:{2}</div>", student.Age, student.Name, student.Language));
        }
        #endregion

        通过Reverse()对查询结果反向排序#region 通过Reverse()对查询结果反向排序
        Response.Write("<hr>通过Reverse()对查询结果反向排序：<br>");
        var students3 = (from student in StudentList
                         orderby student.Age
                         select student)
                         .Reverse();
        foreach (var student in students3)
        {
            Response.Write(string.Format("<div class='result'>age:{0}; name:{1}</div>", student.Age, student.Name));
        }
        #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

结果显示