c# - MVC 验证低于/高于其他值

Question

在我想接受最小值/最大值的 MVC.Net 中验证模型的最佳方法是什么？

不是字段的单个最小/最大值。但是用户需要单独的字段来指定最小值/最大值。

public class FinanceModel{
   public int MinimumCost {get;set;}
   public int MaximumCost {get;set;}
}

所以我需要确保最小成本总是小于最大成本。

Answer 1

有一个名为Foolproof的 NuGet 包可为您提供这些注释。也就是说 - 编写自定义属性既简单又好习惯。

使用万无一失看起来像：

public class FinanceModel{
   public int MinimumCost {get;set;}

   [GreaterThan("MinimumCost")]
   public int MaximumCost {get;set;}
}

Answer 2

您可以使用自定义验证属性，这是我的日期示例。但是您也可以将它与整数一起使用。

首先，这是模型：

public DateTime Beggining { get; set; }

[IsDateAfterAttribute("Beggining", true, ErrorMessageResourceType = typeof(LocalizationHelper), ErrorMessageResourceName = "PeriodErrorMessage")]
public DateTime End { get; set; }

这是属性本身：

public sealed class IsDateAfterAttribute : ValidationAttribute, IClientValidatable
{
    private readonly string testedPropertyName;
    private readonly bool allowEqualDates;

    public IsDateAfterAttribute(string testedPropertyName, bool allowEqualDates = false)
    {
        this.testedPropertyName = testedPropertyName;
        this.allowEqualDates = allowEqualDates;
    }

    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
    {
        var propertyTestedInfo = validationContext.ObjectType.GetProperty(this.testedPropertyName);
        if (propertyTestedInfo == null)
        {
            return new ValidationResult(string.Format("unknown property {0}", this.testedPropertyName));
        }

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

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

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

        // Compare values
        if ((DateTime)value >= (DateTime)propertyTestedValue)
        {
            if (this.allowEqualDates && value == propertyTestedValue)
            {
                return ValidationResult.Success;
            }
            else if ((DateTime)value > (DateTime)propertyTestedValue)
            {
                return ValidationResult.Success;
            }
        }

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

    public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
    {
        var rule = new ModelClientValidationRule
        {
            ErrorMessage = this.ErrorMessageString,
            ValidationType = "isdateafter"
        };
        rule.ValidationParameters["propertytested"] = this.testedPropertyName;
        rule.ValidationParameters["allowequaldates"] = this.allowEqualDates;
        yield return rule;
    }

Answer 3

对于使用 allowEqualDates 和 propertyTested 参数的客户端验证（对上面 Boranas 答案的补充，但评论太长）：

// definition for the isdateafter validation rule
if ($.validator && $.validator.unobtrusive) {
    $.validator.addMethod('isdateafter', function (value, element, params) {
        value = Date.parse(value);
        var otherDate = Date.parse($(params.compareTo).val());
        if (isNaN(value) || isNaN(otherDate))
            return true;
        return value > otherDate || (value == otherDate && params.allowEqualDates);
    });
    $.validator.unobtrusive.adapters.add('isdateafter', ['propertytested', 'allowequaldates'], function (options) {
        options.rules['isdateafter'] = {
            'allowEqualDates': options.params['allowequaldates'],
            'compareTo': '#' + options.params['propertytested']
        };
        options.messages['isdateafter'] = options.message;
    });
}

更多信息：不显眼的验证，jquery 验证

Answer 4

在 VB 中用于整数：

模型

<UtilController.IsIntegerGreatherOrEqualThan("PropertyNameNumberBegins", "PeriodErrorMessage")>
        Public Property PropertyNameNumberEnds As Nullable(Of Integer)

验证

Public Class IsIntegerGreatherOrEqualThan
        Inherits ValidationAttribute

        Private otherPropertyName As String
        Private errorMessage As String

        Public Sub New(ByVal otherPropertyName As String, ByVal errorMessage As String)
            Me.otherPropertyName = otherPropertyName
            Me.errorMessage = errorMessage
        End Sub

        Protected Overrides Function IsValid(thisPropertyValue As Object, validationContext As ValidationContext) As ValidationResult

            Dim otherPropertyTestedInfo = validationContext.ObjectType.GetProperty(Me.otherPropertyName)

            If (otherPropertyTestedInfo Is Nothing) Then
                Return New ValidationResult(String.Format("unknown property {0}", Me.otherPropertyName))
            End If

            Dim otherPropertyTestedValue = otherPropertyTestedInfo.GetValue(validationContext.ObjectInstance, Nothing)

            If (thisPropertyValue Is Nothing) Then
                Return ValidationResult.Success
            End If

            ''  Compare values
            If (CType(thisPropertyValue, Integer) >= CType(otherPropertyTestedValue, Integer)) Then
                Return ValidationResult.Success
            End If

            ''  Wrong
            Return New ValidationResult(errorMessage)
        End Function
    End Class

Answer 5

为什么不使用 Range Validator。句法：

    [Range(typeof(int), "0", "100", ErrorMessage = "{0} can only be between {1} and {2}")]
    public int Percentage { get; set; }