轉載：利用List的Sort()、Find()、FindAll()、Exist()來解決一些問題
2010-07-22 11:33 Koy 阅读(165) 评论(0) 编辑 收藏 举报[ASP.NET]利用List的Sort()、Find()、FindAll()、Exist()來解決一些問題
轉載自：http://www.dotblogs.com.tw/puma/archive/2009/05/28/asp.net-generic-list-sort-find-findall-exsit.aspx
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
01 |
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="GenericList.aspx.cs" Inherits="GenericList" %> |
02 |
03 |
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> |
04 |
05 |
<html xmlns="http://www.w3.org/1999/xhtml"> |
06 |
<head runat="server"> |
07 |
<title>GenericList</title> |
08 |
</head> |
09 |
<body> |
10 |
<form id="form1" runat="server"> |
11 |
<div> |
12 |
原始資料： |
13 |
<asp:GridView ID="GridView1" runat="server"> |
14 |
</asp:GridView> |
15 |
</div> |
16 |
</form> |
17 |
</body> |
18 |
</html> |
GenericList.aspx.cs
001 |
using System; |
002 |
using System.Collections.Generic; |
003 |
using System.Web; |
004 |
using System.Web.UI; |
005 |
using System.Web.UI.WebControls; |
006 |
007 |
public partial class GenericList : System.Web.UI.Page |
008 |
{ |
009 |
010 |
protected void Page_Load(object sender, EventArgs e) |
011 |
{ |
012 |
List<Person> lstPerson = new List<Person>(); |
013 |
lstPerson.Add(new Person(1, "puma", 10)); |
014 |
lstPerson.Add(new Person(2, "F6 Team", 20)); |
015 |
lstPerson.Add(new Person(3, "ASP.NET", 30)); |
016 |
lstPerson.Add(new Person(4, "Dotblogs", 40)); |
017 |
018 |
//原始資料顯示在GridView上 |
019 |
this.GridView1.DataSource = lstPerson; |
020 |
this.GridView1.DataBind(); |
021 |
022 |
023 |
024 |
//List<T>.Find() |
025 |
//找出Name='puma'的Person |
026 |
Response.Write("找出Name='puma'的Person→ "); |
027 |
Response.Write(lstPerson.Find(delegate(Person p) {return p.Name == "puma"; }).ToString() + "<p>"); |
028 |
029 |
030 |
031 |
//List<T>.FindAll() |
032 |
//找出Age>10的數目 |
033 |
Response.Write("找出Age>10的數目→ "); |
034 |
Response.Write(lstPerson.FindAll(delegate(Person p) {return p.Age > 10; }).Count.ToString() + "<p>"); |
035 |
036 |
037 |
038 |
//List<T>.Exists() |
039 |
//檢查Name='F6'是否存在 |
040 |
Response.Write("檢查Name='F6'是否存在→ "); |
041 |
Response.Write(lstPerson.Exists(delegate(Person p) {return p.Name == "F6"; }).ToString() + "<p>"); |
042 |
043 |
044 |
045 |
//List<T>.Sort() |
046 |
//依Name升冪排序 |
047 |
Response.Write("<p>依Name升冪排序↑<br/>"); |
048 |
lstPerson.Sort(delegate(Person p1, Person p2) { returnComparer<string>.Default.Compare(p1.Name, p2.Name); }); |
049 |
foreach (Person p in lstPerson) |
050 |
{ |
051 |
Response.Write(p.ToString() + "<br/>"); |
052 |
} |
053 |
054 |
055 |
056 |
//List<T>.Sort() |
057 |
//依Name降冪排序 |
058 |
Response.Write("<p>依Name降冪排序↓<br/>"); |
059 |
lstPerson.Sort(delegate(Person p1, Person p2) { returnComparer<string>.Default.Compare(p2.Name, p1.Name); }); |
060 |
foreach (Person p in lstPerson) |
061 |
{ |
062 |
Response.Write(p.ToString() + "<br/>"); |
063 |
} |
064 |
} |
065 |
} |
066 |
067 |
public class Person |
068 |
{ |
069 |
private int _ID; |
070 |
private string _Name; |
071 |
private int _Age; |
072 |
073 |
public Person(int ID, string Name, int Age) |
074 |
{ |
075 |
_ID = ID; |
076 |
_Name = Name; |
077 |
_Age = Age; |
078 |
} |
079 |
080 |
public int ID |
081 |
{ |
082 |
set { _ID = value; } |
083 |
get { return _ID; } |
084 |
} |
085 |
086 |
public string Name |
087 |
{ |
088 |
set { _Name = value; } |
089 |
get { return _Name; } |
090 |
} |
091 |
092 |
public int Age |
093 |
{ |
094 |
set { _Age = value; } |
095 |
get { return _Age; } |
096 |
} |
097 |
098 |
public override string ToString() |
099 |
{ |
100 |
return string.Format("ID：{0}，Name：{1}，Age：{2}", _ID, _Name, _Age); |
101 |
} |
102 |
} |
執行結果：
參考網址：
http://blogs.msdn.com/kcwalina/archive/2004/06/22/162533.aspx
http://www.dotblogs.com.tw/chhuang/archive/2008/05/08/3908.aspx
