Async Await

1.async修饰的方法可理解为异步方法（必须要配合await,否则和普通方法无异）。也就是说如果不配合await，就算方法加了async修饰它也只是个普通方法。

2.当async方法执行遇到await,则立即将控制权转移到async方法的调用者.

3.async 修饰的是方法，await等待的则是个任务。（await后面接Task）

 

using System;
using System.Threading;
using System.Threading.Tasks;

namespace async_await
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("I am watching the game while i am eating ice cream...");
            Tortoise();
            Thread.Sleep(2000);
            Console.WriteLine("I finished my ice cream, and I saw the rabbit was at the end");
            Console.Read();
        }


        public static async void Tortoise()
        {
            Console.WriteLine("game start..");
            await Task.Run(() => {
                Thread.Sleep(9000);
                Console.WriteLine("tortoise finally finished the game....");
            });

        }
    }



}