最近寫案子常常用到List<T>,這個東西還真好用

因為它有下列東西：

List<T>.Sort() → 排序T

List<T>.Find() → 找出一個T

List<T>.FindAll() →找出多個T

List<T>.Exist() →判斷T是否存在

小弟就寫個範例介紹這些東西吧..

GenericList.aspx




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<%@ Page Language="C#" AutoEventWireup="true" CodeFile="GenericList.aspx.cs" Inherits="GenericList" %>


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


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<html xmlns="http://www.w3.org/1999/xhtml">


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<head runat="server">


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    <title>GenericList</title>


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</head>


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<body>


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    <form id="form1" runat="server">


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    <div>


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        原始資料：


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        <asp:GridView ID="GridView1" runat="server">


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        </asp:GridView>


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    </div>


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    </form>


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</body>


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</html>


GenericList.aspx.cs




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using System;


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using System.Collections.Generic;


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using System.Web;


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using System.Web.UI;


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using System.Web.UI.WebControls;


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


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{


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    protected void Page_Load(object sender, EventArgs e)


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    {


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        List<Person> lstPerson = new List<Person>();


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        lstPerson.Add(new Person(1, "puma", 10));


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        lstPerson.Add(new Person(2, "F6 Team", 20));


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        lstPerson.Add(new Person(3, "ASP.NET", 30));


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        lstPerson.Add(new Person(4, "Dotblogs", 40));


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        //原始資料顯示在GridView上


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        this.GridView1.DataSource = lstPerson;


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        this.GridView1.DataBind();


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        //List<T>.Find()


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        //找出Name='puma'的Person


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        Response.Write("找出Name='puma'的Person→ ");


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        Response.Write(lstPerson.Find(delegate(Person p) { return p.Name == "puma"; }).ToString() + "<p>");


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        //List<T>.FindAll()


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        //找出Age>10的數目


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        Response.Write("找出Age>10的數目→ ");


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        Response.Write(lstPerson.FindAll(delegate(Person p) { return p.Age > 10; }).Count.ToString() + "<p>");


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        //List<T>.Exists()


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        //檢查Name='F6'是否存在


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        Response.Write("檢查Name='F6'是否存在→ ");


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        Response.Write(lstPerson.Exists(delegate(Person p) { return p.Name == "F6"; }).ToString() + "<p>");


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        //List<T>.Sort()


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        //依Name升冪排序


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        Response.Write("<p>依Name升冪排序↑<br/>");


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        lstPerson.Sort(delegate(Person p1, Person p2) { return Comparer<string>.Default.Compare(p1.Name, p2.Name); });


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        foreach (Person p in lstPerson)


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        {


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            Response.Write(p.ToString() + "<br/>");


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        }


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        //List<T>.Sort()


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        //依Name降冪排序


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        Response.Write("<p>依Name降冪排序↓<br/>");


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        lstPerson.Sort(delegate(Person p1, Person p2) { return Comparer<string>.Default.Compare(p2.Name, p1.Name); });


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        foreach (Person p in lstPerson)


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        {


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            Response.Write(p.ToString() + "<br/>");


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        }


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    }


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}


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public class Person


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{


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    private int _ID;


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    private string _Name;


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    private int _Age;


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    public Person(int ID, string Name, int Age)


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    {


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        _ID = ID;


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        _Name = Name;


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        _Age = Age;


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    }


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    public int ID


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    {


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        set { _ID = value; }


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        get { return _ID; }


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    }


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    public string Name


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    {


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        set { _Name = value; }


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        get { return _Name; }


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    }


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    public int Age


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    {


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        set { _Age = value; }


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        get { return _Age; }


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    }


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    public override string ToString()


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    {


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        return string.Format("ID：{0}，Name：{1}，Age：{2}", _ID, _Name, _Age);


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    }


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}


執行結果：