asp.net-mvc-4 – 可为空的可选url参数的ASP.NET MVC 4 RC Web A

public class ValidationActionFilter : ActionFilterAttribute
{
    public override void OnActionExecuting(HttpActionContext actionContext)
    {
        if (actionContext.ModelState.IsValid)
        {
            return;
        }

        var errors = new List<KeyValuePair<string,string>>();
        foreach (var key in actionContext.ModelState.Keys.Where(key =>
            actionContext.ModelState[key].Errors.Any()))
        {
            errors.AddRange(actionContext.ModelState[key].Errors
                  .Select(er => new KeyValuePair<string,string>(key,er.ErrorMessage)));
        }

        actionContext.Response =
            actionContext.Request.CreateResponse(HttpStatusCode.BadRequest,errors);
    }
}

然后我将它添加到Global.asax中的全局装配器：

configuration.Filters.Add(new ValidationActionFilter());

它适用于我的大多数操作,但与具有可选和可空请求参数的操作不一样.

例如：

我创建了一条路线：

routes.MapHttpRoute(
    name: "Optional parameters route",routeTemplate: "api/{controller}",defaults: new { skip = UrlParameter.Optional,take = UrlParameter.Optional });

我的ProductsController中有一个动作：

public HttpResponseMessage GetAllProducts(int? skip,int? take)
{
    var products = this._productService.GetProducts(skip,take,MaxTake);

    return this.Request.CreateResponse(HttpStatusCode.OK,this._backwardMapper.Map(products));
}

现在当我请求这个网址时：http：// locahost / api / products我得到了一个包含403状态代码和以下内容的响应：

[
{
    "Key": "skip.Nullable`1","Value": "A value is required but was not present in the request."
},{
    "Key": "take.Nullable`1","Value": "A value is required but was not present in the request."
}
]

我认为这不应该作为验证错误出现,因为这些参数都是可选的和可空的.

有没有人遇到过这个问题并找到了解决方案？