C#单例模式的泛型定义

取自某热门网游

using System;

public class Singleton<T> where T : class, new()
{
	private static T _Instance;

	public static T Instance
	{
		get
		{
			if (Singleton<T>._Instance == null)
			{
				Singleton<T>._Instance = Activator.CreateInstance<T>();
			}
			return Singleton<T>._Instance;
		}
	}

	static Singleton()
	{
		Singleton<T>._Instance = Activator.CreateInstance<T>();
	}

	public static void CreateInstance()
	{
		if (Singleton<T>._Instance == null)
		{
			Singleton<T>._Instance = Activator.CreateInstance<T>();
		}
	}

	public static void DestroyInstance()
	{
		if (Singleton<T>._Instance != null)
		{
			Singleton<T>._Instance = (T)((object)null);
		}
	}

	public static T GetInstance()
	{
		if (Singleton<T>._Instance == null)
		{
			Singleton<T>._Instance = Activator.CreateInstance<T>();
		}
		return Singleton<T>._Instance;
	}
}

using System;
using UnityEngine;

namespace Engine
{
	public abstract class MonoSingleton<T> : MonoBehaviour where T : MonoSingleton<T>
	{
		private static T m_Instance;

		public static T Instance
		{
			get
			{
				if (MonoSingleton<T>.m_Instance == null)
				{
					MonoSingleton<T>.m_Instance = (UnityEngine.Object.FindObjectOfType(typeof(T)) as T);
				}
				return MonoSingleton<T>.m_Instance;
			}
		}

		protected void Awake()
		{
			if (MonoSingleton<T>.m_Instance == null)
			{
				MonoSingleton<T>.m_Instance = (this as T);
			}
		}

		private void OnDestroy()
		{
			MonoSingleton<T>.m_Instance = (T)((object)null);
		}

		protected void OnApplicationQuit()
		{
			MonoSingleton<T>.m_Instance = (T)((object)null);
		}
	}
}