乐在其中设计模式(C#) - 单例模式(Singleton Pattern)
Singleton
using System;
using System.Collections.Generic;
using System.Text;
namespace Pattern.Singleton
{
/// <summary>
/// 泛型实现单例模式
/// </summary>
/// <typeparam name="T">需要实现单例的类</typeparam>
public class Singleton<T> where T : new()
{
/// <summary>
/// 返回类的实例
/// </summary>
public static T Instance
{
get { return SingletonCreator.instance; }
}
class SingletonCreator
{
internal static readonly T instance = new T();
}
}
}
using System.Collections.Generic;
using System.Text;
namespace Pattern.Singleton
{
/// <summary>
/// 泛型实现单例模式
/// </summary>
/// <typeparam name="T">需要实现单例的类</typeparam>
public class Singleton<T> where T : new()
{
/// <summary>
/// 返回类的实例
/// </summary>
public static T Instance
{
get { return SingletonCreator.instance; }
}
class SingletonCreator
{
internal static readonly T instance = new T();
}
}
}
Test
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using Pattern.Singleton;
public partial class Singleton : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
// 使用单例模式,保证一个类仅有一个实例
Response.Write(Singleton<Test>.Instance.Time);
Response.Write("<br />");
Response.Write(Singleton<Test>.Instance.Time);
Response.Write("<br />");
// 不用单例模式
Test t = new Test();
Response.Write(t.Time);
Response.Write("<br />");
Test t2 = new Test();
Response.Write(t2.Time);
Response.Write("<br />");
}
}
public class Test
{
private DateTime _time;
public Test()
{
System.Threading.Thread.Sleep(3000);
_time = DateTime.Now;
}
public string Time
{
get { return _time.ToString(); }
}
}
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using Pattern.Singleton;
public partial class Singleton : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
// 使用单例模式,保证一个类仅有一个实例
Response.Write(Singleton<Test>.Instance.Time);
Response.Write("<br />");
Response.Write(Singleton<Test>.Instance.Time);
Response.Write("<br />");
// 不用单例模式
Test t = new Test();
Response.Write(t.Time);
Response.Write("<br />");
Test t2 = new Test();
Response.Write(t2.Time);
Response.Write("<br />");
}
}
public class Test
{
private DateTime _time;
public Test()
{
System.Threading.Thread.Sleep(3000);
_time = DateTime.Now;
}
public string Time
{
get { return _time.ToString(); }
}
}
运行结果
2007-2-10 22:35:11
2007-2-10 22:35:11
2007-2-10 22:35:14
2007-2-10 22:35:17
参考
http://www.dofactory.com/Patterns/PatternSingleton.aspx
OK
[源码下载]
2007-2-10 22:35:11
2007-2-10 22:35:11
2007-2-10 22:35:14
2007-2-10 22:35:17
参考
http://www.dofactory.com/Patterns/PatternSingleton.aspx
OK
[源码下载]
本文转自webabcd 51CTO博客,原文链接:http://blog.51cto.com/webabcd/344515,如需转载请自行联系原作者