举例讲解C#编程中对设计模式中的单例模式的运用

using System; 
using System.Collections; 
using System.Collections.Generic; 
  
  
public class Singleton : MonoBehaviour 
{ 
  private static GameObject m_Container = null; 
  private static string m_Name = "Singleton"; 
  private static Dictionary<string, object> m_SingletonMap = new Dictionary<string, object>(); 
  private static bool m_IsDestroying = false; 
    
  public static bool IsDestroying 
  { 
    get { return m_IsDestroying; } 
  } 
    
  public static bool IsCreatedInstance(string Name) 
  { 
    if(m_Container == null) 
    { 
      return false; 
    } 
    if (m_SingletonMap!=null && m_SingletonMap.ContainsKey(Name))  
    { 
      return true; 
    } 
    return false; 
      
  } 
  public static object getInstance (string Name) 
  { 
    if(m_Container == null) 
    { 
      Debug.Log("Create Singleton."); 
      m_Container = new GameObject (); 
      m_Container.name = m_Name;   
      m_Container.AddComponent (typeof(Singleton)); 
    } 
    if (!m_SingletonMap.ContainsKey(Name)) { 
      if(System.Type.GetType(Name) != null) 
      { 
        m_SingletonMap.Add(Name, m_Container.AddComponent (System.Type.GetType(Name))); 
      } 
      else 
      { 
        Debug.LogWarning("Singleton Type ERROR! (" + Name + ")"); 
      } 
    } 
    return m_SingletonMap[Name]; 
  }   
    
  public void RemoveInstance(string Name) 
  { 
    if (m_Container != null && m_SingletonMap.ContainsKey(Name)) 
    { 
      UnityEngine.Object.Destroy((UnityEngine.Object)(m_SingletonMap[Name])); 
      m_SingletonMap.Remove(Name); 
        
      Debug.LogWarning("Singleton REMOVE! (" + Name + ")"); 
    } 
  } 
  
  void Awake () 
  { 
    Debug.Log("Awake Singleton."); 
    DontDestroyOnLoad (gameObject); 
  } 
    
  void Start() 
  { 
    Debug.Log("Start Singleton."); 
  }   
    
  void Update() 
  { 
  } 
    
  void OnApplicationQuit() 
  { 
    Debug.Log("Destroy Singleton"); 
    if(m_Container != null) 
    { 
      GameObject.Destroy(m_Container); 
      m_Container = null; 
      m_IsDestroying = true; 
    }       
  } 
    
}

// 该类不是一个公开类
  // 但是该类的实现应用了单例模式
  internal sealed class SR
  {
    private static SR loader;
    internal SR()
    {
    }
    // 主要是因为该类不是公有，所以这个全部访问点也定义为私有的了
    // 但是思想还是用到了单例模式的思想的
    private static SR GetLoader()
    {
      if (loader == null)
      {
        SR sr = new SR();
        Interlocked.CompareExchange<SR>(ref loader, sr, null);
      }
      return loader;
    }
    // 这个公有方法中调用了GetLoader方法的
    public static object GetObject(string name)
    {
      SR loader = GetLoader();
      if (loader == null)
      {
        return null;
      }
      return loader.resources.GetObject(name, Culture);
    }
  }