static void Main(string[] args)
{
Program p = new Program();
Console.WriteLine(1);
p.Go();
Console.WriteLine(2);
Console.ReadLine();
}
async Task Go()
{
Console.WriteLine(3);
await a();
Console.WriteLine(4);
}
async Task a()
{
Console.WriteLine(5);
int i = await b();
Console.WriteLine(i);
}
async Task<int> b()
{
Console.WriteLine(6);
await Task.Delay(5000);
Console.WriteLine(7);
int i = 999;
return i;
}

2以后暂停几秒后继续执行