使用ValidationAttribute进行自定义验证不会触发客户端验证

Question

我创建了一个从ValidationAttribute派生的自定义验证器.我的undertsandng是它将为客户端脚本生成足够的元数据以自动验证(使用jquery.validate).自定义验证器在服务器端正常工作.但它不会在客户端激发错误消息.(其他默认验证器,如"StringLength"在客户端也正常工作.)我们如何纠正它？

public class Person
{
    [Required(ErrorMessage = "First name required")]
    public string FirstName { get; set; }

    [CustomStartLetterMatch("FirstName")]
    [StringLength(5,ErrorMessage = "Must be under 5 characters")]
    public string LastName { get; set; }

    [Range(18,50,ErrorMessage="Must be between 18 and 50")]
    public int Age { get; set; }


}


public sealed class CustomStartLetterMatch : ValidationAttribute
{

    private const string _defaultErrorMessage = " First letter of '{0}' must be same as first letetr of '{1}'";
    private string _basePropertyName;

    public CustomStartLetterMatch(string basePropertyName)
        : base(_defaultErrorMessage)
    {
        _basePropertyName = basePropertyName;
    }


    //Override FormatErrorMessage Method
    public override string FormatErrorMessage(string name)
    {
        return string.Format(_defaultErrorMessage, name, _basePropertyName);
    }


    //Override IsValid
    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
    {
        //Get PropertyInfo Object
        var basePropertyInfo = validationContext.ObjectType.GetProperty(_basePropertyName);
        var baseValue = (string)basePropertyInfo.GetValue(validationContext.ObjectInstance, null);
        var currentValue = (string)value;


        string firstLetterBaseValue = baseValue.Substring(0, 1);
        string firstLetterCurrentValue = currentValue.Substring(0, 1);

        //Comparision
        if (!string.Equals(firstLetterBaseValue, firstLetterCurrentValue))
        {
            var message = FormatErrorMessage(validationContext.DisplayName);
            return new ValidationResult(message);
        }

        //Default return - This means there were no validation error
        return null;
    }

}

视图

@model MyValidationTEST.Person

<script src="@Url.Content("~/Scripts/jquery-1.5.1.min.js")" type="text/javascript">  </script>

@*UnObtrusive*@
<script src="@Url.Content("~/Scripts/jquery.validate.min.js")" type="text/javascript"></script>
<script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.min.js")" type="text/javascript"></script>




@using (Html.BeginForm()) {
@Html.ValidationSummary(true)
<fieldset>
    <legend>Person</legend>

    <div class="editor-label">
        @Html.LabelFor(model => model.FirstName)
    </div>
    <div class="editor-field">
        @Html.EditorFor(model => model.FirstName)
        @Html.ValidationMessageFor(model => model.FirstName)
    </div>

    <div class="editor-label">
        @Html.LabelFor(model => model.LastName)
    </div>
    <div class="editor-field">
        @Html.EditorFor(model => model.LastName)
        @Html.ValidationMessageFor(model => model.LastName)
    </div>

    <div class="editor-label">
        @Html.LabelFor(model => model.Age)
    </div>
    <div class="editor-field">
        @Html.EditorFor(model => model.Age)
        @Html.ValidationMessageFor(model => model.Age)
    </div>



    <p>
        <input type="submit" value="Create" />
    </p>
</fieldset>
}

<div>
@Html.ActionLink("Back to List", "Index")
</div>

读:

1. MVC3中的IValidatableObject - 客户端验证

2. 在ASP.NET MVC3中,如何使用非常相似但略有不同的视图模型来保持DRY？

3. http://odetocode.com/Blogs/scott/archive/2011/02/22/custom-data-annotation-validator-part-ii-client-code.aspx

4. http://bradwilson.typepad.com/blog/2010/10/mvc3-unobtrusive-validation.html

5. ASP.NET MVC 3带参数的客户端验证

6. 如何在客户端将自定义ValidationAttribute呈现为"da​​ta-val-xx"属性？

7. ASP.NET-MVC3中"自我验证模型"中的客户端验证

Answer 1

我的undertsandng是它将为客户端脚本生成足够的元数据以自动验证(使用jquery.validate).

你的理解是错误的.您不可能期望有足够的元数据来生成客户端验证.在这种IsValid方法中,你可以做任何事情.您甚至可以调用非托管C++库来执行验证.您不可能期望ASP.NET MVC 3会在客户端上反映出这一点.

如果要为此类自定义验证逻辑启用客户端验证,则需要实现IClientValidatable并添加自定义适配器.在此适配器中,您必须重新实现在服务器上执行的相同逻辑,但这次使用javascript.

这是一个例子.这是另一个.

正如您所看到的,客户端验证可以正常使用一些简单的规则,例如必需和填充,一旦您开始进行一些真正的验证,您将不得不自己实现它.