gistfile1.txt

public class MyAdaptor : IDataAnnotationsValidatorAdapter
    {
        protected readonly ValidationAttribute attribute;

        public MyAdaptor(MatchAttribute attribute)
        {
            this.attribute = attribute;
        }

        public IEnumerable<ModelValidationRule> GetRules()
        {
            yield return new MatchValidationRule(attribute.FormatErrorMessage,
                new[] { ((MatchAttribute)attribute).SourceProperty },
                ((MatchAttribute)attribute).SourceProperty,
                ((MatchAttribute)attribute).MatchProperty);
        }

        public IEnumerable<ModelValidationError> Validate(object instance)
        {
            var context =
                new ValidationContext(instance, null, null)
                {
                    MemberName = ((MatchAttribute)attribute).SourceProperty
                };

            var result =
         attribute.GetValidationResult(instance, context);

            if (result != null)
            {
                yield return new ModelValidationError(result.MemberNames, attribute.FormatErrorMessage);
            }

            yield break;
        }

    }

    public class MatchValidationRule : ModelValidationRule
    {
        public MatchValidationRule(Func<string, string> errorMessageFormatter, IEnumerable<string> memberNames, string SourceProp, string MatchProp)
            : base("Match", errorMessageFormatter, memberNames)
        {
            this.SourceProperty = SourceProp;
            this.MatchProperty = MatchProp;
        }

        public string SourceProperty { get; set; }
        public string MatchProperty { get; set; }
    }

    public class MyFactory : IModelValidatorFactory
    {

        #region IModelValidatorFactory Members

        public IModelValidator Create(Type type)
        {
            var attributes = type.GetCustomAttributes(typeof(MatchAttribute), false);

            MatchAttribute classAttribute = null;
            if (attributes.Length > 0)
            {
                classAttribute = (MatchAttribute)attributes[0];
            }

            return new MyModelValidator(new MyAdaptor(classAttribute));
        }

        #endregion
    }

    public class MyModelValidator : IModelValidator
    {
        MyAdaptor adaptor;
        public MyModelValidator(MyAdaptor adapter)
        {
            adaptor = adapter;
        }

        #region IModelValidator Members

        public ModelValidationDescriptor Description
        {
            get
            {
                return new ModelValidationDescriptor(adaptor.GetRules());
            }
        }

        public ModelValidationResult Validate(object instance)
        {
            var errors = new List<ModelValidationError>();


            errors.AddRange(adaptor.Validate(instance));


            return new ModelValidationResult(errors);
        }

        #endregion
    }