异常捕获

            Console.WriteLine("请输入一个数字：");
            int number=0;
            bool  b=true;
            try
            {
                number = int.Parse(Console.ReadLine());
            }
            catch {
                Console.WriteLine( "您输入的格式不正确" );
                b = false;

            }
            if(b)
            {
            Console.WriteLine(number*2);
            }
            Console.ReadLine();