狼翔天地

出處：http://dsqiu.iteye.com/blog/2017655

如題

此為unity singletion用法 使用Template方式並繼承MonoBehaviour  

 using UnityEngine;

///
/// Be aware this will not prevent a non singleton constructor
/// such as `T myT = new T();`
/// To prevent that, add `protected T () {}` to your singleton class.
///
/// As a note, this is made as MonoBehaviour because we need Coroutines.
///
public class Singleton : MonoBehaviour where T : MonoBehaviour
{
private static T _instance;

private static object _lock = new object();

public static T Instance
{
get
{
if (applicationIsQuitting) {
Debug.LogWarning("[Singleton] Instance '"+ typeof(T) +
"' already destroyed on application quit." +
" Won't create again - returning null.");
return null;
}

lock(_lock)
{
if (_instance == null)
{
_instance = (T) FindObjectOfType(typeof(T));

if ( FindObjectsOfType(typeof(T)).Length > 1 )
{
Debug.LogError("[Singleton] Something went really wrong " +
" - there should never be more than 1 singleton!" +
" Reopenning the scene might fix it.");
return _instance;
}

if (_instance == null)
{
GameObject singleton = new GameObject();


_instance = singleton.AddComponent();
singleton.name = "(singleton) "+ typeof(T).ToString();

DontDestroyOnLoad(singleton);

Debug.Log("[Singleton] An instance of " + typeof(T) +
" is needed in the scene, so '" + singleton +
"' was created with DontDestroyOnLoad.");
} else {
Debug.Log("[Singleton] Using instance already created: " +
_instance.gameObject.name);
}
}

return _instance;
}
}
}

private static bool applicationIsQuitting = false;
///
/// When Unity quits, it destroys objects in a random order.
/// In principle, a Singleton is only destroyed when application quits.
/// If any script calls Instance after it have been destroyed,
/// it will create a buggy ghost object that will stay on the Editor scene
/// even after stopping playing the Application. Really bad!
/// So, this was made to be sure we're not creating that buggy ghost object.
///
public void OnDestroy () {
applicationIsQuitting = true;
}
}