Fluent Validation For .NET

//.net 中数据验证，一个开源的项目，直接下载
 1 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().When(customer => customer.HasDiscount);
     RuleFor(customer => customer.Address).Length(, );
     RuleFor(customer => customer.Postcode).Must(BeAValidPostcode).WithMessage("Please specify a valid postcode");
   }

   private bool BeAValidPostcode(string postcode) {
     // custom postcode validating logic goes here
   }
 }

 Customer customer = new Customer();
 CustomerValidator validator = new CustomerValidator();
 ValidationResult results = validator.Validate(customer);

 bool validationSucceeded = results.IsValid;
 IList<ValidationFailure> failures = results.Errors;