属性依赖于另一个场 [英] attribute dependent on another field

问题描述

在我的ASP.NET MVC应用程序的模式，我想验证一个文本框，因为只有当一个特定的复选框被选中必需的。

In a model of my ASP.NET MVC application I would like validate a textbox as required only if a specific checkbox is checked.

像

public bool retired {get, set};

[RequiredIf("retired",true)]
public string retirementAge {get, set};

我怎么能这样做？

How can I do that?

感谢您。

推荐答案

看看这个：<一href=\"http://blogs.msdn.com/b/simonince/archive/2010/06/04/conditional-validation-in-mvc.aspx\">http://blogs.msdn.com/b/simonince/archive/2010/06/04/conditional-validation-in-mvc.aspx

我已经改装成的code有所以满足我的需求。也许你从这些变化中受益。

I've modded the code somewhat to suit my needs. Perhaps you benefit from those changes as well.

public class RequiredIfAttribute : ValidationAttribute
{
    private RequiredAttribute innerAttribute = new RequiredAttribute();
    public string DependentUpon { get; set; }
    public object Value { get; set; }

    public RequiredIfAttribute(string dependentUpon, object value)
    {
        this.DependentUpon = dependentUpon;
        this.Value = value;
    }

    public RequiredIfAttribute(string dependentUpon)
    {
        this.DependentUpon = dependentUpon;
        this.Value = null;
    }

    public override bool IsValid(object value)
    {
        return innerAttribute.IsValid(value);
    }
}

public class RequiredIfValidator : DataAnnotationsModelValidator<RequiredIfAttribute>
{
    public RequiredIfValidator(ModelMetadata metadata, ControllerContext context, RequiredIfAttribute attribute)
        : base(metadata, context, attribute)
    { }

    public override IEnumerable<ModelClientValidationRule> GetClientValidationRules()
    {
        // no client validation - I might well blog about this soon!
        return base.GetClientValidationRules();
    }

    public override IEnumerable<ModelValidationResult> Validate(object container)
    {
        // get a reference to the property this validation depends upon
        var field = Metadata.ContainerType.GetProperty(Attribute.DependentUpon);

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

            // compare the value against the target value
            if ((value != null && Attribute.Value == null) || (value != null && value.Equals(Attribute.Value)))
            {
                // match => means we should try validating this field
                if (!Attribute.IsValid(Metadata.Model))
                    // validation failed - return an error
                    yield return new ModelValidationResult { Message = ErrorMessage };
            }
        }
    }
}

然后使用它：

public DateTime? DeptDateTime { get; set; }
[RequiredIf("DeptDateTime")]
public string DeptAirline { get; set; }

这篇关于属性依赖于另一个场的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！