public class Phone

    {

        [Key] //主键

        public int Id { get; set; }

        [Required] //不能为空

        [MinLength(),MaxLength()]  //最小长度2，最大长度20

        public string Name { get; set; }

        [StringLength()]  //字符串长度为50

        public string Number { get; set; }

        public DateTime CreateDate { get; set; }

        public bool IsValid { get; set; }

        public string Carrieroperator { get; set; }

    }