我对我的模型有一个价值，它必须在我的模型上的另外两个值的范围内。
例如：
public class RangeValidationSampleModel
{
int Value { get; set; }
int MinValue { get; set; }
int MaxValue { get; set; }
}
当然，我不能将这些Min / MaxValues传递给我的DataAnnotations属性，因为它们必须是常量值。
我确定我需要建立自己的验证属性，但是我没有这么做，不能把我的想法放在一起，应该如何工作。
我搜索了大约一个小时，并且已经看到了各种解决方案来构建自定义验证，但是找不到任何东西来解决这个特殊的问题，使用MVC3不显眼的验证。
解决方法
您可以为此编写自定义验证属性：
public class DynamicRangeValidator : ValidationAttribute,IClientValidatable
{
private readonly string _minPropertyName;
private readonly string _maxPropertyName;
public DynamicRangeValidator(string minPropertyName,string maxPropertyName)
{
_minPropertyName = minPropertyName;
_maxPropertyName = maxPropertyName;
}
protected override ValidationResult IsValid(object value,ValidationContext validationContext)
{
var minProperty = validationContext.ObjectType.GetProperty(_minPropertyName);
var maxProperty = validationContext.ObjectType.GetProperty(_maxPropertyName);
if (minProperty == null)
{
return new ValidationResult(string.Format("Unknown property {0}",_minPropertyName));
}
if (maxProperty == null)
{
return new ValidationResult(string.Format("Unknown property {0}",_maxPropertyName));
}
int minValue = (int)minProperty.GetValue(validationContext.ObjectInstance,null);
int maxValue = (int)maxProperty.GetValue(validationContext.ObjectInstance,null);
int currentValue = (int)value;
if (currentValue <= minValue || currentValue >= maxValue)
{
return new ValidationResult(
string.Format(
ErrorMessage,minValue,maxValue
)
);
}
return null;
}
public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata Metadata,ControllerContext context)
{
var rule = new ModelClientValidationRule
{
ValidationType = "dynamicrange",ErrorMessage = this.ErrorMessage,};
rule.ValidationParameters["minvalueproperty"] = _minPropertyName;
rule.ValidationParameters["maxvalueproperty"] = _maxPropertyName;
yield return rule;
}
}
然后用它来装饰你的视图模型：
public class RangeValidationSampleModel
{
[DynamicRangeValidator("MinValue","MaxValue",ErrorMessage = "Value must be between {0} and {1}")]
public int Value { get; set; }
public int MinValue { get; set; }
public int MaxValue { get; set; }
}
那么你可以有一个控制器提供视图：
public class HomeController : Controller
{
public ActionResult Index()
{
return View(new RangeValidationSampleModel
{
Value = 5,MinValue = 6,MaxValue = 8
});
}
[HttpPost]
public ActionResult Index(RangeValidationSampleModel model)
{
return View(model);
}
}
并且当然是：
@model RangeValidationSampleModel
<script src="@Url.Content("~/Scripts/jquery.validate.js")" type="text/javascript"></script>
<script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.js")" type="text/javascript"></script>
<script type="text/javascript">
$.validator.unobtrusive.adapters.add('dynamicrange',['minvalueproperty','maxvalueproperty'],function (options) {
options.rules['dynamicrange'] = options.params;
if (options.message != null) {
$.validator.messages.dynamicrange = options.message;
}
}
);
$.validator.addMethod('dynamicrange',function (value,element,params) {
var minValue = parseInt($('input[name="' + params.minvalueproperty + '"]').val(),10);
var maxValue = parseInt($('input[name="' + params.maxvalueproperty + '"]').val(),10);
var currentValue = parseInt(value,10);
if (isNaN(minValue) || isNaN(maxValue) || isNaN(currentValue) || minValue >= currentValue || currentValue >= maxValue) {
var message = $(element).attr('data-val-dynamicrange');
$.validator.messages.dynamicrange = $.validator.format(message,maxValue);
return false;
}
return true;
},'');
</script>
@using (Html.BeginForm())
{
<div>
@Html.LabelFor(x => x.Value)
@Html.EditorFor(x => x.Value)
@Html.ValidationMessageFor(x => x.Value)
</div>
<div>
@Html.LabelFor(x => x.MinValue)
@Html.EditorFor(x => x.MinValue)
</div>
<div>
@Html.LabelFor(x => x.MaxValue)
@Html.EditorFor(x => x.MaxValue)
</div>
<button type="submit">OK</button>
}
显然，自定义适配器注册应该在一个外部的javascript文件中执行，以避免污染视图，但为了这个目的和简洁的这篇文章我把它放在视图内。
