Unity中的单实例

static GUIManager myInstance;
public static GUIManager Instance
{
    get
    {
        if (myInstance == null)
            myInstance = FindObjectOfType(typeof(GUIManager)) as GUIManager;

        return myInstance;
    }
}

static GUIManager myInstance;
public static GUIManager Instance { get { return myInstance; } }

void Start()
{
    myInstance = this;
}

public class Singleton<T> : MonoBehaviour where T : MonoBehaviour
{
   protected static T instance;

   /**
      Returns the instance of this singleton.
   */
   public static T Instance
   {
      get
      {
         if(instance == null)
         {
            instance = (T) FindObjectOfType(typeof(T));

            if (instance == null)
            {
               Debug.LogError("An instance of " + typeof(T) +
                  " is needed in the scene, but there is none.");
            }
         }

         return instance;
      }
   }
}