public class PErson
 {
     public string NameField;
     public int Id { get; set; }
     public string Surname { get; set; }
     public string Forename { get; set; }
     public List<Person> Children { get; set; }
     public string[] Nicknames { get; set; }
     public DateTime DateOfBirth { get; set; }
     public int&#63; Nullableint { get; set; }
     public Person()
     {
         Children = new List<Person>();
         Orders = new List<Order>();
     }
     public int CalculateSalary()
     {
         return 20;
     }
     public Address Address { get; set; }
     public IList<Order> Orders { get; set; }
     public string Email { get; set; }
     public decimal Discount { get; set; }
     public double Age { get; set; }
     public int AnotherInt { get; set; }
     public string CredITCard { get; set; }
     public int? OtherNullableInt { get; set; }
 }
 public interface IAddress
 {
     string Line1 { get; set; }
     string Line2 { get; set; }
     string Town { get; set; }
     string County { get; set; }
     string Postcode { get; set; }
     Country Country { get; set; }
 }
 public class Address : IAddress
 {
     public string Line1 { get; set; }
     public string Line2 { get; set; }
     public string Town { get; set; }
     public string County { get; set; }
     public string Postcode { get; set; }
     public Country Country { get; set; }
     public int Id { get; set; }
 }
 public class Country
 {
     public string Name { get; set; }
 }
 public interface IOrder
 {
     decimal Amount { get; }
 }
 public class Order : IOrder
 {
     public string PRoductName { get; set; }
     public decimal Amount { get; set; }
 }

 using FluentValidation;
 public class CustomerValidator: AbstractValidator<Customer>
 {
   public CustomerValidator()
   {
     RuleFor(customer => customer.Surname).NotEmpty();
     RuleFor(customer => customer.Forename).NotEmpty().WithMessage("Please specify a First name");
     RuleFor(customer => customer.Discount).NotEqual(0).When(customer => customer.HasDiscount);
     RuleFor(customer => customer.Address).Length(20, 250);
     RuleFor(customer => customer.Postcode).Must(BeAValidPostcode).WithMessage("Please specify a valid postcode");
   }
   private bool BeAValidPostcode(string postcode)
   {
     // custom postcode validating LOGic goes here
   }
 }
 // 手动验证规则
 Customer customer = new Customer();
 CustomerValidator validator = new CustomerValidator();
 ValidationResult results = validator.Validate(customer);
 bool validationSucceeded = results.IsValid;
 IList<ValidationFailure> failures = results.Errors;

 // 在Global.aSAX.cs中的Applicaton_Start()函数中注册为asp.net mvc默认的验证规则库。
 // fluent validation
 FluentValidationModelValidatorProvider provider = new FluentValidationModelValidatorProvider(new AttributedValidatorFactory());
 ;modelValidatorProviders.Providers.Add(provider);
 DataAnnotationsModelValidatorProvider.AddImplicitRequiredAttributeForValueTypes = false;