C# ValidationAttribute.GetValidationResult方法代码示例

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

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

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

            yield break;
        }

        /// <summary>
        /// Validates the given instance.
        /// </summary>
        /// <param name="instance">The instance that should be validated.</param>
        /// <param name="attribute">The <see cref="ValidationAttribute"/> that should be handled.</param>
        /// <param name="descriptor">A <see cref="PropertyDescriptor"/> instance for the property that is being validated.</param>
        /// <returns>An <see cref="IEnumerable{T}"/> of <see cref="ModelValidationRule"/> instances.</returns>
        public virtual IEnumerable<ModelValidationError> Validate(object instance, ValidationAttribute attribute, PropertyDescriptor descriptor)
        {
            var context =
                new ValidationContext(instance, null, null)
                {
                    MemberName = descriptor == null ? null : descriptor.Name
                };

            if(descriptor != null)
            {
                instance = descriptor.GetValue(instance);
            }

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

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

 private bool validate(ValidationAttribute v, object value)
 {
     return v.GetValidationResult(value, new ValidationContext(ValidationContext, null, null)) == ValidationResult.Success;
 }

        /// <summary>
        /// Tests whether a value is valid against a single <see cref="ValidationAttribute"/> using the <see cref="ValidationContext"/>.
        /// </summary>
        /// <param name="value">The value to be tested for validity.</param>
        /// <param name="validationContext">Describes the property member to validate.</param>
        /// <param name="attribute">The validation attribute to test.</param>
        /// <param name="validationError">The validation error that occurs during validation.  Will be <c>null</c> when the return value is <c>true</c>.</param>
        /// <returns><c>true</c> if the value is valid.</returns>
        /// <exception cref="ArgumentNullException">When <paramref name="validationContext"/> is null.</exception>
        private static bool TryValidate(object value, ValidationContext validationContext, ValidationAttribute attribute, out ValidationError validationError)
        {
            if (validationContext == null) {
                throw new ArgumentNullException("validationContext");
            }

            ValidationResult validationResult = attribute.GetValidationResult(value, validationContext);
            if (validationResult != ValidationResult.Success) {
                validationError = new ValidationError(attribute, value, validationResult);
                return false;
            }

            validationError = null;
            return true;
        }

        /// <summary>
        /// Validates the given instance.
        /// </summary>
        /// <param name="instance">The instance that should be validated.</param>
        /// <param name="attribute">The <see cref="ValidationAttribute"/> that should be handled.</param>
        /// <param name="descriptor">A <see cref="PropertyDescriptor"/> instance for the property that is being validated.</param>
        /// <param name="context">The <see cref="NancyContext"/> of the current request.</param>
        /// <returns>An <see cref="IEnumerable{T}"/> of <see cref="ModelValidationRule"/> instances.</returns>
        public virtual IEnumerable<ModelValidationError> Validate(object instance, ValidationAttribute attribute, PropertyDescriptor descriptor, NancyContext context)
        {
            var validationContext =
                new ValidationContext(instance, null, null)
                {
                    MemberName = descriptor == null ? null : descriptor.Name
                };

            // When running on Mono the Display attribute is not auto populated so for now we do it ourselves
            if (IsRunningOnMono)
            {
                var displayName = this.GetDisplayNameForMember(instance, validationContext.MemberName);
                if (!string.IsNullOrEmpty(displayName))
                {
                    validationContext.DisplayName = displayName;
                }
            }

            if (descriptor != null)
            {
                // Display(Name) will auto populate the context, while DisplayName() needs to be manually set
                if (validationContext.MemberName == validationContext.DisplayName && !string.IsNullOrEmpty(descriptor.DisplayName))
                {
                    validationContext.DisplayName = descriptor.DisplayName;
                }

                instance = descriptor.GetValue(instance);
            }

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

            if (result != null)
            {
                yield return this.GetValidationError(result, validationContext, attribute);
            }
        }

 private static string GetFinalMemberName(ValidationAttribute attrib, object contextModel, object mamberValue, string givenMemberName, string givenDisplayName)
 {
     return attrib.GetValidationResult(mamberValue, new ValidationContext(contextModel)
     {
         MemberName = givenMemberName,
         DisplayName = givenDisplayName
     })?.MemberNames.Single();
 }