3-2 从降级的例子 认识Polly套路

1 没有返回值的降级

Policy policy = Policy.Handle<Exception>().Fallback(() =>
            {
                Console.WriteLine("我是你爸爸");
            });
            policy.Execute(() =>
            {
                Console.WriteLine("开始执行");
                throw new Exception();
                Console.WriteLine("执行结束");
            });

2有返回值的降级

            Policy<string> policy = Policy<string>.Handle<Exception>().Fallback(() =>
            {
                Console.WriteLine("苔痕上阶绿");
                return "我是希罗多德";
            });
            string response = policy.Execute(() =>
              {
                  Console.WriteLine("开始执行");
                  throw new Exception();
                  Console.WriteLine("执行完毕");
                  return "我的名字叫做阿基米德";
              });
            Console.WriteLine(response);