1 public sealed class Singlton
 2 {
 3     static Singlton instance = null;
 4     private　Singlton() { }
 6  
 7     public static Singlton Instance
 8     {
 9         get
10         {
11             if (instance == null)
12             {
13                 instance = new Singlton();
14             }
15             return instance;
16         }   
17     }   
18 }

 1 public sealed class Singlton
 2 {
 3     static Singlton instance = null;
 4  
 5     static readonly object o = new object();
 6  
 7     Singlton()
 8     { }
 9  
10     public static Singlton Instance
11     {
12         get
13         {
14             lock (o)
15             {
16                 if (instance == null)
17                 {
18                     instance= new Singlton();
19                 }
20             21             }
                return instance;
22         }   
23     }   
24 }

 1 public sealed class Singlton
 2 {
 3     static readonly Singlton instance = null;
 4  
 5     static Singlton()
 6     { instance = new Singlton();}
 7  
 8     public static Singlton Instance
 9     {
10         get
11         {
12             return instance;
13         }
14     }
15 }

 1     public class CategoryRepository : Car_RentalRepositoryBase, ICategoryRepository
 2     {
 3         #region 靜態樹結構，每1分鐘去獲一下數據庫
 4         static List<Category> categoryList = null;
 5         /// <summary>
 6         /// 數(shu)據實體
 7         /// </summary>
 8         public static volatile List<Category> Instance = null;
 9         static CategoryRepository categoryRepository = new CategoryRepository();
10         static System.Timers.Timer sysTimer = new System.Timers.Timer(600000);
11         static CategoryRepository()
12         {
13             Reload();//第一次加載
14             sysTimer.AutoReset = true;
15             sysTimer.Enabled = true;
16             sysTimer.Elapsed += new System.Timers.ElapsedEventHandler(sysTimer_Elapsed);
17             sysTimer.Start();
18         }
19 
20         /// <summary>
21         /// 被訂(ding)閱了Elapsed事(shi)件的方法,每(mei)隔一段時(shi)間去重新獲取數(shu)據列(lie)表
22         /// </summary>
23         /// <param name="sender"></param>
24         /// <param name="e"></param>
25         static void sysTimer_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
26         {
27             Reload();
28         }
29 
30         internal static void Reload()
31         {
32             categoryList = categoryRepository.GetModel().OrderBy(i => i.SortNumber).ToList();
33             Instance = categoryList.Where(i => i.ID != 1).ToList();
34         }
35 }

 1  /// <summary>
 2     /// 泛(fan)型單例基類
 3     /// </summary>
 4     public abstract class Singleton<TEntity> where TEntity : class
 5     {
 6         private static readonly Lazy<TEntity> _instance
 7           = new Lazy<TEntity>(() =>
 8           {
 9               var ctors = typeof(TEntity).GetConstructors(
10                   BindingFlags.Instance
11                   | BindingFlags.NonPublic
12                   | BindingFlags.Public);
13               if (ctors.Count() != 1)
14                   throw new InvalidOperationException(String.Format("Type {0} must have exactly one constructor.", typeof(TEntity)));
15               var ctor = ctors.SingleOrDefault(c => c.GetParameters().Count() == 0 && c.IsPrivate);
16               if (ctor == null)
17                   throw new InvalidOperationException(String.Format("The constructor for {0} must be private and take no parameters.", typeof(TEntity)));
18               return (TEntity)ctor.Invoke(null);
19           });
20 
21         public static TEntity Instance
22         {
23             get { return _instance.Value; }
24         }
25     }