[C#/ASP.NET]中List<T>真的非常好用。一个例子简单说明一下List<>中Sort()、Find()、FindAll()、Exist()的使用方法
简单介绍：
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
示例代码：
页面文件GenericList.aspx
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | <%@ Page Language= "C#" AutoEventWireup= "true" CodeFile= "GenericList.aspx.cs" Inherits= "GenericList" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "" > <html xmlns= "" > <head runat= "server" > <title>GenericList</title> </head> <body> <form id= "form1" runat= "server" > <div> 原始資料： <asp:GridView ID= "GridView1" runat= "server" > </asp:GridView> </div> </form> </body> </html> |
后台代码文件GenericList.aspx.cs
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 | using System; using System.Collections.Generic; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; public partial class GenericList : System.Web.UI.Page { protected void Page_Load( object sender, EventArgs e) { List<Person> lstPerson = new List<Person>(); lstPerson.Add( new Person(1, "puma" , 10)); lstPerson.Add( new Person(2, "F6 Team" , 20)); lstPerson.Add( new Person(3, "ASP.NET" , 30)); lstPerson.Add( new Person(4, "Dotblogs" , 40)); //原始資料顯示在GridView上 this .GridView1.DataSource = lstPerson; this .GridView1.DataBind(); //List<T>.Find() //找出Name='puma'的Person Response.Write( "找出Name='puma'的Person→ " ); Response.Write(lstPerson.Find( delegate (Person p) { return p.Name == "puma" ; }).ToString() + "<p>" ); //List<T>.FindAll() //找出Age>10的數目 Response.Write( "找出Age>10的數目→ " ); Response.Write(lstPerson.FindAll( delegate (Person p) { return p.Age > 10; }).Count.ToString() + "<p>" ); //List<T>.Exists() //檢查Name='F6'是否存在 Response.Write( "檢查Name='F6'是否存在→ " ); Response.Write(lstPerson.Exists( delegate (Person p) { return p.Name == "F6" ; }).ToString() + "<p>" ); //List<T>.Sort() //依Name升冪排序 Response.Write( "<p>依Name升冪排序↑<br/>" ); lstPerson.Sort( delegate (Person p1, Person p2) { return Comparer< string >.Default.Compare(p1.Name, p2.Name); }); foreach (Person p in lstPerson) { Response.Write(p.ToString() + "<br/>" ); } //List<T>.Sort() //依Name降冪排序 Response.Write( "<p>依Name降冪排序↓<br/>" ); lstPerson.Sort( delegate (Person p1, Person p2) { return Comparer< string >.Default.Compare(p2.Name, p1.Name); }); foreach (Person p in lstPerson) { Response.Write(p.ToString() + "<br/>" ); } } } public class Person { private int _ID; private string _Name; private int _Age; public Person( int ID, string Name, int Age) { _ID = ID; _Name = Name; _Age = Age; } public int ID { set { _ID = value; } get { return _ID; } } public string Name { set { _Name = value; } get { return _Name; } } public int Age { set { _Age = value; } get { return _Age; } } public override string ToString() { return string .Format( "ID：{0}，Name：{1}，Age：{2}" , _ID, _Name, _Age); } } |
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