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();
        }