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;
    }

}

查看

@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：

Answer 1

我的undertsandng是它将为其生成足够的元数据客户端脚本自动验证（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。在这个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one example。这是another one。

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。

使用ValidationAttribute进行自定义验证不会触发客户端验证

1 个答案: