Model层的类如下:

public class Order      {          public int Id { get; set; }          public decimal Amount { get; set; }          public string CustomerName { get; set; }          public string Status { get; set; }      }

public  class Person      {          public string Name { get; set; }          public int Age { get; set; }      }

Program.cs代码如下:

 class Program      {          //AutoResetEvent 允许线程通过发信号互相通信。通常，此通信涉及线程需要独占访问的资源。          //线程通过调用 AutoResetEvent 上的 WaitOne 来等待信号。如果 AutoResetEvent 处于非终止状态，则该线程阻塞，并等待当前控制资源的线程,通过调用 Set 发出资源可用的信号。          //调用 Set 向 AutoResetEvent 发信号以释放等待线程。AutoResetEvent 将保持终止状态，直到一个正在等待的线程被释放，然后自动返回非终止状态。如果没有任何线程在等待，则状态将无限期地保持为终止状态。          //可以通过将一个布尔值传递给构造函数来控制 AutoResetEvent 的初始状态，如果初始状态为终止状态，则为 true；否则为 false。            //通俗的来讲只有等myResetEven.Set()成功运行后,myResetEven.WaitOne()才能够获得运行机会;Set是发信号，WaitOne是等待信号，只有发了信号，等待的才会执行。如果不发的话，WaitOne后面的程序就永远不会执行。          private static AutoResetEvent autoSet = new AutoResetEvent(false);              private static List<Person> list = new List<Person>()          {              new Person() {Name = "Rose", Age = 19},              new Person() {Name = "Steve", Age = 45},              new Person() {Name = "Jessica", Age = 20},          };              private static void Main(string[] args)          {              //CheckOrders();              //Common();              //RemoveFromList();              //ExceptionHandling();              //-----------------------------------------------------------------              //--------------------------------模拟非线程安全----------------------------                Thread t1 = new Thread(() =>              {                  //确保等待t2开始之后才运行下面的代码                  autoSet.WaitOne();                  foreach (var item in list)                  {                      Console.WriteLine("t1:" + item.Name);                      Thread.Sleep(1000);                  }              });              t1.Start();              Thread t2 = new Thread(() =>              {                  //通知t1可以执行代码                  autoSet.Set();                  //沉睡1秒是为了确保删除操作在t1的迭代过程中                  Thread.Sleep(1000);                  list.RemoveAt(2);              });              t2.Start();                Console.ReadKey();          }            public static void CheckOrders()          {              List<Order> orders = new List<Order>()              {                  new Order { Id = 123, Amount = 29.95m, CustomerName = "Mark", Status = "Delivered" },                  new Order { Id = 456, Amount = 45.00m, CustomerName = "Steph", Status = "Refunded" },                  new Order { Id = 768, Amount = 32.50m, CustomerName = "Claire", Status = "Delivered" },              };                bool anyRefunded = orders.Any(o => o.Status == "Refunded");              if (anyRefunded)              {                  Console.WriteLine("There are refunded orders");              }              else              {                  Console.WriteLine("No refunds");              }                bool allDelivered = orders.All(o => o.Status == "Delivered");              if (allDelivered)              {                  Console.WriteLine("Everything was delivered");              }              else              {                  Console.WriteLine("Not everything was delivered");              }          }            public static void Common()          {              //距离圣诞节的天数              var daysToChristmas = (new DateTime(DateTime.Today.Year, 12, 25) - DateTime.Today).TotalDays;              Console.WriteLine(daysToChristmas);                //-----------------------------------------------------------------              int SUM = "10,5,0,8,10,1,4,0,10,1"                  .Split(',')                  .Select(int.Parse)                  .OrderBy(n => n)                  .Skip(3)                  .Sum();              Console.WriteLine(SUM);              //-----------------------------------------------------------------              var customers = new[] {                  new { Name = "Annie", Email = "annie@test.com" },                  new { Name = "Ben", Email = "" },                  new { Name = "Lily", Email = "lily@test.com" },                  new { Name = "Joel", Email = "joel@test.com" },                  new { Name = "Sam", Email = "" },              };              foreach (var customer in                  from c in customers                  where !String.IsNullOrEmpty(c.Email)                  select c)              {                  Console.WriteLine("Sending email to {0}", customer.Name);              }              //效果同上              foreach (var customer in customers.Where(c => !String.IsNullOrEmpty(c.Email)))              {                  Console.WriteLine("Sending email to {0}", customer.Name);              }          }            public static void RemoveFromList()          {              Func<List<string>> makeList = () => Enumerable.Range(1, 10000000).Select(n => ("Item " + n + "")).ToList();              var itemsToRemove = new[] { "Item 0", "Item 1", "Item 50", "Item 1000", "Item 999999", "Item 9999999" };              var stopwatch = new Stopwatch();              var list = makeList();                stopwatch.Start();              foreach (var item in itemsToRemove)              {                  list.Remove(item);              }              stopwatch.Stop();                Console.WriteLine(list.Count + "Foreach took {0}ms", stopwatch.ElapsedMilliseconds);                list = makeList();                  stopwatch.Restart();              var newList = list.Except(itemsToRemove).ToList(); //效率极低              stopwatch.Stop();                Console.WriteLine(newList.Count + "Except took {0}ms", stopwatch.ElapsedMilliseconds);          }              public static void ExceptionHandling()          {              var numbers = Enumerable.Range(1, 10)                      .Select(n => 5 - n)                      .Select(n =>                      {                          try                          {                              return 10 / n;                          }                          catch (Exception e)                          {                              Console.WriteLine("Error in lambda: " + e.Message);                              return -1;                          }                      });                foreach (var n in numbers)              {                  Console.WriteLine(n);              }          }        }

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