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");

            });

            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);