如何在客户端验证中验证两个变量规则？

Question

我有以下 poco：

public class CabinetItem
{
    [Required]
    [Display(...)]
    public double Width { get; set; }

    public double MinWidth { get; }
}

我想弄清楚的是，当MinWidth 可能是什么时，我如何验证Width 大于MinWidth？最小宽度是取决于橱柜项目的约束。注意：还有一个MaxWidth，为了简化这个问题，我省略了。

Answer 1

选项 1：

foolproof nuget 包在您的情况下可能非常有用。

安装foolproof nuget 包并使用其额外有用的属性，如下所示：

public class CabinetItem
{
    [Required]
    [Display(...)]
    [GreaterThan("MinWidth")]
    public double Width { get; set; }

    public double MinWidth { get; }
}

还有其他功能：

• [是]
• [等于]
• [NotEqualTo]
• [大于]
• [小于]
• [GreaterThanOrEqualTo]
• [LessThanOrEqualTo]

---

资源： Is there a way through data annotations to verify that one date property is greater than or equal to another date property?

Answer 2

您可以创建CustomValidationAttribute

以此为例：

    public class GreaterThanAttribute : ValidationAttribute, IClientValidatable
    {
        private readonly string _testedPropertyName;
        private readonly bool _allowEqualValues;
        private readonly string _testedPropertyDisplayName;

        public override string FormatErrorMessage(string displayName)
        {
            return string.Format(ErrorMessages.GreaterThan_Message, displayName, _testedPropertyDisplayName);
        }

        public GreaterThanAttribute(string testedPropertyName, Type resourceType, string testedPropertyDisplayNameKey, bool allowEqualValues = false)
        {
            _testedPropertyName = testedPropertyName;
            _allowEqualValues = allowEqualValues;
            var rm = new ResourceManager(resourceType);
            _testedPropertyDisplayName = rm.GetString(testedPropertyDisplayNameKey);            
        }

        protected override ValidationResult IsValid(object value, ValidationContext validationContext)
        {
            var propertyTestedInfo = validationContext.ObjectType.GetProperty(_testedPropertyName);

            if (propertyTestedInfo == null)
            {
                return new ValidationResult(string.Format("unknown property {0}", _testedPropertyName));
            }

            var propertyTestedValue = propertyTestedInfo.GetValue(validationContext.ObjectInstance, null);

            if (value == null || !(value is Decimal))
            {
                return ValidationResult.Success;
            }

            if (propertyTestedValue == null || !(propertyTestedValue is Decimal))
            {
                return ValidationResult.Success;
            }

            // Compare values
            if ((Decimal)value >= (Decimal)propertyTestedValue)
            {
                if (_allowEqualValues && value == propertyTestedValue)
                {
                    return ValidationResult.Success;
                }
                else if ((Decimal)value > (Decimal)propertyTestedValue)
                {
                    return ValidationResult.Success;
                }
            }

            return new ValidationResult(FormatErrorMessage(validationContext.DisplayName));
        }

        public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
        {
            var rule = new ModelClientValidationRule
            {
                ErrorMessage = FormatErrorMessage(metadata.DisplayName),
                ValidationType = "greaterthan"
            };
            rule.ValidationParameters["propertytested"] = _testedPropertyName;
            rule.ValidationParameters["allowequalvalues"] = _allowEqualValues;
            yield return rule;
        }
    }

你可以这样使用它：

public Decimal MyProperty1 { get; set; }

[GreaterThanAttribute("MyProperty1", typeof(Strings), "Error_String")]
public Decimal MyProperty2 { get; set; }

[GreaterThanAttribute("MyProperty2", typeof(Strings), "Error_String")]
public Decimal MyProperty3 { get; set; }

在客户端，您可以添加它以进行客户端验证：

jQuery.validator.unobtrusive.adapters.add('greaterthan', ['propertytested', 'allowequalvalues'], function (options) {
            options.params["allowequalvalues"] = options.params["allowequalvalues"] === "True" ||
                                                 options.params["allowequalvalues"] === "true" ||
                                                 options.params["allowequalvalues"] === true ? true : false;

            options.rules['greaterthan'] = options.params;
            options.messages['greaterthan'] = options.message;
        });
jQuery.validator.addMethod("greaterthan", function (value, element, params) {        
            var properyTestedvalue= $('input[name="' + params.propertytested + '"]').val();
            if (!value || !properyTestedvalue) return true;
            return (params.allowequalvalues) ? parseFloat(properyTestedvalue) <= parseFloat(value) : parseFloat(properyTestedvalue) < parseFloat(value);
        }, '');