c# list 查询和排序 .

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1)前台代码(default.aspx)

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="ListTest.Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

2)后台代码

a)default.aspx.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace ListTest
{
    public partial class Default : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                BindStudent();
            }
        }
        /// <summary>
        /// 绑定student
        /// </summary>
        private void BindStudent()
        {
            gvwStudent.DataSource = SortItems();
            gvwStudent.DataBind();
        }
        /// <summary>
        /// 根据id排序
        /// </summary>
        /// <returns></returns>
        private List<Student> SortItems()
        {
            List<Student> items = GetItems();
            items.Sort();
            return items;
        }
        /// <summary>
        /// 根据name和sex获取students
        /// </summary>
        /// <returns></returns>
        private IEnumerable<Student> GetItemsByNameAndSex()
        {
            IEnumerable<Student> items = GetItems().Where(u => u.Name == "lisi"&&u.Sex=="female");
            return items;
        }
        /// <summary>
        /// 根据id获取student
        /// </summary>
        /// <returns></returns>
        private Student GetItemById()
        {
            Student item = GetItems().SingleOrDefault(u => u.Id == 3);
            return item;
        }
        /// <summary>
        /// 获取所有的student
        /// </summary>
        /// <returns></returns>
        private List<Student> GetItems()
        {
            List<Student> items = new List<Student>();
            items.Add(new Student(3,"zhangsan","male"));
            items.Add(new Student(1,"lisi","female"));
            items.Add(new Student(2,"wangwu","female"));
            items.Add(new Student(4,"lisi","male"));
            return items;
        }
    }
}

b)Student.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace ListTest
{
    public class Student:IComparable
    {
        public Student(int id, string name,string sex)
        {
            this.Id = id;
            this.Name = name;
            this.Sex = sex;
        }
        private int id;

        public int Id
        {
            get { return id; }
            set { id = value; }
        }
        private string name;

        public string Name
        {
            get { return name; }
            set { name = value; }
        }
        private string sex;

        public string Sex
        {
            get { return sex; }
            set { sex = value; }
        }
        /// <summary>
        /// 根据id排序
        /// </summary>
        /// <param name="obj"></param>
        /// <returns></returns>
        public int CompareTo(object obj)
        {
            if (obj is Student)
            {
                Student anotherItem = obj as Student;
                return this.Id - anotherItem.Id;//asc
                //return anotherItem.Id - this.Id; //desc
            }
            throw new ArgumentException("object is not a student");
        }

}
}