原文地址:
http://www.dotblogs.com.tw/puma/archive/2009/05/28/asp.net-generic-list-sort-find-findall-exsit.aspx#12190
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>
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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：
http://blogs.msdn.com/kcwalina/archive/2004/06/22/162533.aspx
http://www.dotblogs.com.tw/chhuang/archive/2008/05/08/3908.aspx