Question

我已经在互联网上关注了一些文章和教程，以便创建一个自定义验证属性，该属性也支持asp.net mvc 4网站中的客户端验证。这就是我现在所拥有的：

RequiredIfAttribute.cs

[AttributeUsage(AttributeTargets.Property, AllowMultiple = true)] //Added
public class RequiredIfAttribute : ValidationAttribute, IClientValidatable
{
    private readonly string condition;
    private string propertyName; //Added

    public RequiredIfAttribute(string condition)
    {
        this.condition = condition;
        this.propertyName = propertyName; //Added
    }

    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
    {
        PropertyInfo propertyInfo = validationContext.ObjectType.GetProperty(this.propertyName); //Added
        Delegate conditionFunction = CreateExpression(validationContext.ObjectType, _condition);
        bool conditionMet = (bool)conditionFunction.DynamicInvoke(validationContext.ObjectInstance);

        if (conditionMet)
        {
            if (value == null)
            {
                return new ValidationResult(FormatErrorMessage(null));
            }
        }

        return ValidationResult.Success;
    }

    private Delegate CreateExpression(Type objectType, string expression)
    {
        LambdaExpression lambdaExpression = System.Linq.Dynamic.DynamicExpression.ParseLambda(objectType, typeof(bool), expression); //Added
        Delegate function = lambdaExpression.Compile();
        return function;
    }

    public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
    {
        var modelClientValidationRule = new ModelClientValidationRule
        {
            ValidationType = "requiredif",
            ErrorMessage = ErrorMessage //Added
        };

        modelClientValidationRule.ValidationParameters.Add("param", this.propertyName); //Added
        return new List<ModelClientValidationRule> { modelClientValidationRule };
    }
}

然后我在这个类的属性中应用了这个属性

[RequiredIf("InAppPurchase == true", "InAppPurchase", ErrorMessage = "Please enter an in app purchase promotional price")] //Added "InAppPurchase"
public string InAppPurchasePromotionalPrice { get; set; }

public bool InAppPurchase { get; set; }

所以我想要做的是显示一条错误消息，当InAppPurchase字段为true（表示在表单中检查）时，需要字段InAppPurchasePromotionalPrice。以下是视图中的相关代码：

<div class="control-group">
                <label class="control-label" for="InAppPurchase">Does your app include In App Purchase?</label>
                <div class="controls">
                    @Html.CheckBoxFor(o => o.InAppPurchase)
                    @Html.LabelFor(o => o.InAppPurchase, "Yes")
                </div>
            </div>
            <div class="control-group" id="InAppPurchasePromotionalPriceDiv" @(Model.InAppPurchase == true ? Html.Raw("style='display: block;'") : Html.Raw("style='display: none;'"))>
                <label class="control-label" for="InAppPurchasePromotionalPrice">App Friday Promotional Price for In App Purchase: </label>
                <div class="controls">
                    @Html.TextBoxFor(o => o.InAppPurchasePromotionalPrice, new { title = "This should be at the lowest price tier of free or $.99, just for your App Friday date." })
                    <span class="help-inline">
                        @Html.ValidationMessageFor(o => o.InAppPurchasePromotionalPrice)
                    </span>
                </div>
            </div>

此代码完美无缺，但是当我提交表单时，在服务器上请求完整帖子以显示消息。所以我创建了JavaScript代码以启用客户端验证：

requiredif.js

(function ($) {
    $.validator.addMethod('requiredif', function (value, element, params) {
        /*var inAppPurchase = $('#InAppPurchase').is(':checked');

        if (inAppPurchase) {
            return true;
        }

        return false;*/

        var isChecked = $(param).is(':checked');

        if (isChecked) {
            return false;
        }

        return true;
    }, '');

    $.validator.unobtrusive.adapters.add('requiredif', ['param'], function (options) {
        options.rules["requiredif"] = '#' + options.params.param;
        options.messages['requiredif'] = options.message;
    });
})(jQuery);

这是msdn中提出的方法和我找到的教程

当然，我还在表单中插入了所需的脚本：

jquery.unobtrusive-ajax.min.js
jquery.validate.min.js
jquery.validate.unobtrusive.min.js
requiredif.js

但是......客户端验证仍然无效。那么请你帮我找一下我错过的东西？提前谢谢。

Answer 1

看看这个：http://thewayofcode.wordpress.com/tag/custom-unobtrusive-validation/

使用本教程，我的自定义验证代码运行没有问题。我能在您的代码中发现的唯一区别是您创建$.validator.unobtrusive.adapters.add函数的方式。参数有点不同，但问题可能只是您没有定义适配器的rule部分。

尝试使用以下内容：

$.validator.unobtrusive.adapters.add("requiredif", ["requiredif"], function (options) {
    options.rules["requiredif"] = "#" + options.params.requiredif;
    options.messages["requiredif"] = options.message;
});

或者

$.validator.unobtrusive.adapters.add("requiredif", function (options) {
    options.rules["requiredif"] = "#" + options.element.name.replace('.', '_'); // mvc html helpers
    options.messages["requiredif"] = options.message;
});

关于rule（摘自链接）：

此HTML元素的jQuery规则数组。适配器是预期的将项添加到此规则数组中以用于特定的jQuery Validate 它想要附加的验证器。名称是jQuery的名称验证规则，值是jQuery的参数值验证规则。

Answer 2

值得注意的是，[RequiredIf]属性需要添加到视图模型的第二个表单字段中，以便客户端验证能够正常工作。

自定义验证属性中的客户端验证 - asp.net mvc 4

2 个答案: