C#单例模式的三种写法
第一种最简单,但没有考虑线程安全,在多线程时可能会出问题
public class Singleton
{
private static Singleton _instance = null;
private Singleton(){}
public static Singleton CreateInstance()
{
if(_instance == null)
{
_instance = new Singleton();
}
return _instance;
}
}
第二种考虑了线程安全,不过有点烦,但绝对是正规写法,经典的一叉
public class Singleton
{
private volatile static Singleton _instance = null;
private static readonly object lockHelper = new object();
private Singleton(){}
public static Singleton CreateInstance()
{
if(_instance == null)
{
lock(lockHelper)
{
if(_instance == null)
_instance = new Singleton();
}
}
return _instance;
}
}
第三种可能是C#这样的高级语言特有的,实在懒得出奇
public class Singleton
{
private Singleton(){}
public static readonly Singleton instance = new Singleton();
}