using System;

 using System.Collections.Generic;

 using System.Linq;

 using System.Text;

 using System.Threading;

 using System.Threading.Tasks;

 namespace ConAppAsync

 {

     class Program

     {

         //第一步，创建一个普通的耗时的方法

         static string Greeting(string name)

         {

             Thread.Sleep();

             return String.Format("Hello, {0}", name);

         }

         //第二步，用一个异步方法包装上面的方法

         static Task<string> GreetingAsync(string name)

         {

             return Task.Run<string>(() =>

             {

                 return Greeting(name);

             });

         }

         //第三步，再创建一个能调用上面的异步方法的方法, 加关键字 async

         private async static void CallWithAsync()

         {

             //some other tasks

             string result = await GreetingAsync("王海滨");

             //we can add multiple "await" in same "async" method

             string result1 = await GreetingAsync("Ahmed");

             string result2 = await GreetingAsync("Every Body");

             Console.WriteLine(result+result1+result2);

         }

         static void Main(string[] args)

         {

             //最后在主入口调用上面的方法，和调用普通方法一样

             CallWithAsync();

             int length = ;

             for (int i = ; i < length; i++)

             {

                 Console.WriteLine(i);

             }

             Console.ReadKey();

         }

     }

 }