一般写Singleton基本都是一下这个套路
class Singleton
{
public static Singleton instance;
private Singleton()
{
}
public static Singleton Getinstance()
{
if(instatnce == null)
{
instance = new Singleton();
}
return instance;
}
}
但是今天学到一个C#独有的Singleton写法：
class sealed Singleton
{
public static readonly Singleton instance = new Singleton();
private Singleton()
{
}
}
这种写法简单实用，大大减少了代码量。
但是缺点就是无法被继承，并且启动时就被初始化，无法延迟初始化。
我以这种写法，写了一个简单的LoadBalance类。
public sealed class LoadBalancer
{
public static readonly LoadBalancer balancer = new LoadBalancer();
private ArrayList servers = new ArrayList();
private Random random = new Random();
protected LoadBalancer()
{
servers.Add("SERVER I");
servers.Add("SERVER II");
servers.Add("SERVER III");
servers.Add("SERVER IV");
servers.Add("SERVER V");
}
public string Server
{
get
{
int i = random.Next(servers.Count);
return servers[i].ToString();
}
}
}
class Program
{
static void Main(string[] args)
{
LoadBalancer b1 = LoadBalancer.balancer;
LoadBalancer b2 = LoadBalancer.balancer;
LoadBalancer b3 = LoadBalancer.balancer;
LoadBalancer b4 = LoadBalancer.balancer;
if (b1 == b2 || b2 == b3 || b3 == b4)
Console.WriteLine("Same instance");
Console.WriteLine(b1.Server);
Console.WriteLine(b2.Server);
Console.WriteLine(b3.Server);
Console.WriteLine(b4.Server);
Console.ReadLine();
}
}
调用的结果是：
Same instance
SERVER III
SERVER I
SERVER IV
SERVER IV
C# 中的Singleton模式,布布扣,bubuko.com
原文：http://www.cnblogs.com/nonkicat/p/3824503.html