Asp.Net MVC验证相关字段

我目前正在尝试进行MVC验证，遇到了一些问题，根据另一个字段的值需要一个字段。下面是一个例子（我还没有弄清楚）-如果PaymentMethod==“check”，那么ChequeName应该是必需的，否则它可以通过

[Required(ErrorMessage = "Payment Method must be selected")]
public override string PaymentMethod
{ get; set; }

[Required(ErrorMessage = "ChequeName is required")]
public override string ChequeName
{ get; set; }

我正在为[Required]使用System.ComponentModel.DataAnnotations，并扩展了ValidationAttribute以尝试使其正常工作，但我无法传递变量来进行验证（下面的扩展）

实施：

[JEPaymentDetailRequired(PaymentSelected = PaymentMethod, PaymentType = "Cheque", ErrorMessage = "Cheque name must be completed when payment type of cheque")]

有人有过这种验证的经验吗？将其写入控制器会更好吗

---

谢谢您的帮助。

我将在模型中编写验证逻辑，而不是在控制器中。控制器应仅处理视图和模型之间的交互。由于模型需要验证，我认为它被广泛认为是验证逻辑的场所

对于依赖于另一个属性或字段的值的验证，我（不幸地）不知道如何完全避免在模型中为此编写一些代码，如Wrox ASP.NET MVC手册中所示，类似于：

public bool IsValid
{
  get 
  {
    SetRuleViolations();
    return (RuleViolations.Count == 0); 
  }
}

public void SetRuleViolations()
{
  if (this.PaymentMethod == "Cheque" && String.IsNullOrEmpty(this.ChequeName))
  {
    RuleViolations.Add("Cheque name is required", "ChequeName");
  }
}

---

以声明的方式进行所有验证将非常好。我相信您可以创建一个

RequiredDependentAttribute

，但这只能处理这一类逻辑。稍微复杂一点的东西还需要另一个非常具体的属性，等等，这很快就会变得疯狂。

你的问题可以相对简单地通过使用例如

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如果除了服务器上的模型验证之外，还需要客户端验证，我认为最好的方法是自定义验证属性（如Jaroslaw建议的）。我在这里包括了我使用的那个的来源

自定义属性：

public class RequiredIfAttribute : DependentPropertyAttribute
{
    private readonly RequiredAttribute innerAttribute = new RequiredAttribute();

    public object TargetValue { get; set; }


    public RequiredIfAttribute(string dependentProperty, object targetValue) : base(dependentProperty)
    {
        TargetValue = targetValue;
    }


    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
    {
        // get a reference to the property this validation depends upon
        var containerType = validationContext.ObjectInstance.GetType();
        var field = containerType.GetProperty(DependentProperty);

        if (field != null)
        {
            // get the value of the dependent property
            var dependentvalue = field.GetValue(validationContext.ObjectInstance, null);

            // compare the value against the target value
            if ((dependentvalue == null && TargetValue == null) ||
                (dependentvalue != null && dependentvalue.Equals(TargetValue)))
            {
                // match => means we should try validating this field
                if (!innerAttribute.IsValid(value))
                    // validation failed - return an error
                    return new ValidationResult(ErrorMessage, new[] { validationContext.MemberName });
            }
        }

        return ValidationResult.Success;
    }

    public override IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
    {
        var rule = new ModelClientValidationRule
                       {
                           ErrorMessage = FormatErrorMessage(metadata.GetDisplayName()),
                           ValidationType = "requiredif"
                       };

        var depProp = BuildDependentPropertyId(DependentProperty, metadata, context as ViewContext);

        // find the value on the control we depend on;
        // if it's a bool, format it javascript style 
        // (the default is True or False!)
        var targetValue = (TargetValue ?? "").ToString();
        if (TargetValue != null)
            if (TargetValue is bool)
                targetValue = targetValue.ToLower();

        rule.ValidationParameters.Add("dependentproperty", depProp);
        rule.ValidationParameters.Add("targetvalue", targetValue);

        yield return rule;
    }
}

[Required]
public bool IsEmailGiftCertificate { get; set; }

[RequiredIf("IsEmailGiftCertificate", true, ErrorMessage = "Please provide Your Email.")]
public string YourEmail { get; set; }

使用属性装饰属性：

public class RequiredIfAttribute : DependentPropertyAttribute
{
    private readonly RequiredAttribute innerAttribute = new RequiredAttribute();

    public object TargetValue { get; set; }


    public RequiredIfAttribute(string dependentProperty, object targetValue) : base(dependentProperty)
    {
        TargetValue = targetValue;
    }


    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
    {
        // get a reference to the property this validation depends upon
        var containerType = validationContext.ObjectInstance.GetType();
        var field = containerType.GetProperty(DependentProperty);

        if (field != null)
        {
            // get the value of the dependent property
            var dependentvalue = field.GetValue(validationContext.ObjectInstance, null);

            // compare the value against the target value
            if ((dependentvalue == null && TargetValue == null) ||
                (dependentvalue != null && dependentvalue.Equals(TargetValue)))
            {
                // match => means we should try validating this field
                if (!innerAttribute.IsValid(value))
                    // validation failed - return an error
                    return new ValidationResult(ErrorMessage, new[] { validationContext.MemberName });
            }
        }

        return ValidationResult.Success;
    }

    public override IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
    {
        var rule = new ModelClientValidationRule
                       {
                           ErrorMessage = FormatErrorMessage(metadata.GetDisplayName()),
                           ValidationType = "requiredif"
                       };

        var depProp = BuildDependentPropertyId(DependentProperty, metadata, context as ViewContext);

        // find the value on the control we depend on;
        // if it's a bool, format it javascript style 
        // (the default is True or False!)
        var targetValue = (TargetValue ?? "").ToString();
        if (TargetValue != null)
            if (TargetValue is bool)
                targetValue = targetValue.ToLower();

        rule.ValidationParameters.Add("dependentproperty", depProp);
        rule.ValidationParameters.Add("targetvalue", targetValue);

        yield return rule;
    }
}

[Required]
public bool IsEmailGiftCertificate { get; set; }

[RequiredIf("IsEmailGiftCertificate", true, ErrorMessage = "Please provide Your Email.")]
public string YourEmail { get; set; }

---

只需使用Codeplex上提供的万无一失的验证库：

它支持以下“requiredif”验证属性/装饰：

[RequiredIf]
[RequiredIfNot]
[RequiredIfTrue]
[RequiredIfFalse]
[RequiredIfEmpty]
[RequiredIfNotEmpty]
[RequiredIfRegExMatch]
[RequiredIfNotRegExMatch]

开始很容易：

从提供的链接下载软件包

添加对包含的.dll文件的引用

导入包含的javascript文件

确保视图从其HTML中引用包含的javascript文件，以进行不引人注目的javascript和jquery验证

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仔细想想。。。如何设置PaymentSelected=PaymentMethod？你应该得到一个错误，因为PaymentMethod不是一个常量表达式。嗨，Min，你是对的。我原以为我可以这样做，但没用。我只是想展示我所做的尝试，但也评论说它不允许我传递变量。感谢djuth，我已经获取了一个ModelStateDictionary并在模型中对此进行了验证，然后将该dictionary传递回控制器以合并到ModelState中。似乎做到了这一点，并允许我做一些编程工作-不太好，只是做一个声明每个属性，但至少我可以在一个地方得到一切。如果每个属性tho有多个错误，我不确定这将如何进行。我知道这个答案已经有2年了，但我正在尝试让它起作用，基本上它会启动依赖属性的验证，无论第一个属性的值是什么。任何帮助都将不胜感激。

[RequiredIf]
[RequiredIfNot]
[RequiredIfTrue]
[RequiredIfFalse]
[RequiredIfEmpty]
[RequiredIfNotEmpty]
[RequiredIfRegExMatch]
[RequiredIfNotRegExMatch]