c#-线程-异步-await等待返回值

代码 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Threading;
using System.Runtime.CompilerServices;

namespace ConsoleApp7
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("hello word");
            main2();
            Console.ReadKey();
        }
        static async void main2() {
            string r = await getStrAsync();
            Console.WriteLine(r);
        }
        static string getStr() {
            return "str";
        }
        static Task getStrAsync() {
            var t1 = new Task(getStr);
            t1.Start();
            return t1;
        }
    }
}

运行结果