32

我在互联网上关注了一些文章和教程，以创建一个自定义验证属性，该属性还支持 asp.net mvc 4 网站中的客户端验证。这是我到目前为止所拥有的：

必需的IfAttribute.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 };
    }
}

然后我在这样的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 字段为真（这意味着在表单中检查）时需要字段 InAppPurchasePromotionalPrice。以下是视图的相关代码：

<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>

此代码运行良好，但是当我提交表单时，服务器上会请求完整的帖子以显示消息。所以我创建了 JavaScript 代码来启用客户端验证：

必需的if.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);

这是我发现的 msdn 和教程中建议的方式

当然，我还以以下形式插入了所需的脚本：

  1. jquery.unobtrusive-ajax.min.js
  2. jquery.validate.min.js
  3. jquery.validate.unobtrusive.min.js
  4. 必需的if.js

但是...客户端验证仍然不起作用。所以你能帮我找出我错过了什么吗？提前致谢。

4

2 回答 2

40

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

使用本教程，我可以毫无问题地运行我的自定义验证代码。我可以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rule适配器的一部分。

尝试使用这样的东西：

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

或这个

$.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（取自链接）：

此 HTML 元素的 jQuery 规则数组。适配器应该为它想要附加的特定 jQuery Validate 验证器添加项目到这个规则数组。name 是 jQuery Validate 规则的名称，value 是 jQuery Validate 规则的参数值。

于 2013-11-01T12:36:54.227 回答
0

值得注意的是，该[RequiredIf]属性需要添加到视图模型中的第二个表单字段才能使客户端验证正常工作。

于 2013-12-04T16:38:06.550 回答