我有以下简单的类数据注释来控制电话号码的区域:public class PhoneAreaAttribute : ValidationAttribute, IClientValidatable {public const string ValidInitNumber = "0";public const int MinLen = 2;public const int MaxLen = 4;public override bool IsValid(object value){var area = (string)value;if (string.IsNullOrWhiteSpace(area)){return true;}if (area.StartsWith(PhoneAreaAttribute.ValidInitNumber)){return...