C# async await 异步执行方法

代码如下

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

namespace Demo
{

    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine($"{DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")} Main 111");
            Task.Run(() => Post<bool>("http://www.vipsoft.com.cn","VipSoft"));
            Console.WriteLine($"{DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")} Main 222");
            Console.ReadLine();

        }

        public static async Task<bool> Post<T>(string url, string param)
        {
            Console.WriteLine($"{DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")} Post 111");
            bool flag = await SendMessage<T>(DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"));
            if (flag != null)
            {
                Console.WriteLine($"{DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")} 等 SendMessage 执行完");
            }
            Console.WriteLine($"{DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")} Post 222");
            return flag;
        }

        public static async Task<bool> SendMessage<T>(string param)
        {
            Console.WriteLine($"{DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")} SendMessage 111");
            Thread.Sleep(2000);
            Console.WriteLine($"{DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")} SendMessage 222");
            return true;
        }

    }
}