asp.net-mvc-3 - 验证器如何在客户端工作？

Question

我正在开发一个简单的验证器。它适用于服务器端请求，但由于禁止回发，它不适用于客户端。.Net 的RequiredAttribute验证器在客户端工作，不需要回发。

如何更改我的验证器以使其工作？

我的验证器获取一个字符串并检查它是否至少有 5 个字符长。

[AttributeUsage(AttributeTargets.Property | AttributeTargets.Field | 
  AttributeTargets.Parameter, AllowMultiple = false)]
public class MyValidatorAttribute : ValidationAttribute
{
    private readonly int _length = 0;

    public MyValidatorAttribute(int length)
    {
        _length = length;
    }

    protected override ValidationResult IsValid(object value, 
                                         ValidationContext validationContext)
    {
        if (value != null)
        {
            string data = (string)value;
            if (data.Length < _length)
            {
                return new ValidationResult("length is short");
            }
        }
        return ValidationResult.Success;
    }
}

public class MyValidator : DataAnnotationsModelValidator<MyValidatorAttribute>
{
    int minlength = 5;
    string errorMsg = string.Empty;

    public MyValidator(ModelMetadata metadata, 
                       ControllerContext context, 
                       MyValidatorAttribute attribute)
        : base(metadata, context, attribute)
    {
        errorMsg = attribute.ErrorMessage;
    }

    public override IEnumerable<ModelClientValidationRule> 
                                GetClientValidationRules()
    {
        ModelClientValidationRule validationRule = 
                                  new ModelClientValidationRule();

        validationRule.ErrorMessage = errorMsg;
        validationRule.ValidationType = "MyValidator";

        validationRule.ValidationParameters.Add("minlength", minlength);

        return new[] { validationRule };

    }
}