Async和await关键字的用法

async & await 的前世今生（Updated）

static void Main(string[] args)
{
// 异步方式
Console.WriteLine("\n异步方式测试开始！main线程id是{0}",System.Threading.Thread.CurrentThread.ManagedThreadId);
AsyncMethod(0);
//AsyncMethod_taks(10);
Console.WriteLine("异步方式测试结束！");
Console.ReadKey();
}

// 异步操作
private static async void AsyncMethod(int input)
{
Console.WriteLine("进入异步操作！线程id是{0}", System.Threading.Thread.CurrentThread.ManagedThreadId);
var result = await AsyncWork(input);
Console.WriteLine("最终结果{0}, 线程ID是{1}", result, System.Threading.Thread.CurrentThread.ManagedThreadId);
Console.WriteLine("退出异步操作！");
}

// 模拟耗时操作（异步方法）
private static async Task<int> AsyncWork(int val)
{
await Task.Delay(2000);
for (int i = 0; i < 5; ++i)
{
Console.WriteLine("耗时操作{0}, 线程id是 {1}", i, System.Threading.Thread.CurrentThread.ManagedThreadId);
val++;
}
return val;
}