使用TryParse()来执行数值转换

        static void Main()

        {

            var ageText = "25";

            if (int.TryParse(ageText,out int age))

            {

                Console.WriteLine("Hi,My age is {0}",age);

            }

            else

            {

                Console.WriteLine("age {0} is not valid",ageText);

            }

            Console.ReadKey();

        }