代碼如下:

private static volatile T _instance = null; 
private static object objLock = new Object(); 
private T() 
{ 
} 
public static T Instance 
{ 
get 
{ 
if (_instance == null) 
{ 
lock (objLock) 
{ 
if (_instance == null) 
{ 
_instance = new T(); 
} 
} 
} 
return _instance; 
} 
} 

在必要的時候需如果要刷新當前instance，可以這樣寫： 

復制代碼代碼如下:

public static void RefreshInstance() 
{ 
_instance = new T(); 
}