Question

我尝试缓存对ASP.NET MVC3 RC1中的操作方法的调用。

缓存有效，但参数的变化似乎没有。我可以做些什么来使HotOffers的3次调用返回不同的结果，具体取决于productID？

现在的输出是

热门优惠4

我希望输出为

热门优惠4

热门优惠6

热门优惠8

动作

[OutputCache(Duration = 100, VaryByParam = "productId")]
public PartialViewResult HotOffers(int productId)
{
    ProductModel model = new ProductModel { ProductID = productId };
    model.Name = "Meatball";

    return PartialView(model);
}

页面（Index.cshtml）

@{
    View.Title = "Home Page";
}
<p>
<div>
    @Html.Action("HotOffers", new { productid=4})
</div>
<div>
 @Html.Action("HotOffers", new { productid=6})
</div>
 <div>
 @Html.Action("HotOffers", new { productid = 8 })
</div>
</p>

部分（HotOffers.cshtml）

Hot offers
@Model.ProductID

Answer 1

asp.net使用的缓存系统存在于MVC之外，因此仅适用于Urls，然后VaryByParam仅适用于QueryString参数。

我发布了一些代码OutputCache behavior in ASP.NET MVC 3，这可以让你根据参数进行缓存操作。那个特殊的例子我添加了一个“ignore”参数，它实际上会忽略其中一个路由字段，但你可以删除它，你应该没问题。

我想我可以在这里发布sans ignore

public class ActionOutputCacheAttribute : ActionFilterAttribute {
    public ActionOutputCacheAttribute(int cacheDuration) {
        this.cacheDuration = cacheDuration;
    }

    private int cacheDuration;
    private string cacheKey;

    public override void OnActionExecuting(ActionExecutingContext filterContext) {
        string url = filterContext.HttpContext.Request.Url.PathAndQuery;
        this.cacheKey = ComputeCacheKey(filterContext);

        if (filterContext.HttpContext.Cache[this.cacheKey] != null) {
            //Setting the result prevents the action itself to be executed
            filterContext.Result =
            (ActionResult)filterContext.HttpContext.Cache[this.cacheKey];
        }

        base.OnActionExecuting(filterContext);
    }

    public override void OnActionExecuted(ActionExecutedContext filterContext) {
        //Add the ActionResult to cache 
        filterContext.HttpContext.Cache.Add(this.cacheKey, filterContext.Result,null, DateTime.Now.AddSeconds(cacheDuration),
          System.Web.Caching.Cache.NoSlidingExpiration, CacheItemPriority.Normal, null);

        //Add a value in order to know the last time it was cached.
        filterContext.Controller.ViewData["CachedStamp"] = DateTime.Now;

        base.OnActionExecuted(filterContext);
    }

    private string ComputeCacheKey(ActionExecutingContext filterContext) {
        var keyBuilder = new StringBuilder();
        keyBuilder.Append(filterContext.ActionDescriptor.ControllerDescriptor.ControllerName);
        keyBuilder.Append(filterContext.ActionDescriptor.ActionName);

        foreach (var pair in filterContext.RouteData.Values) {
            if(pair.Value != null)
                keyBuilder.AppendFormat("rd{0}_{1}_", pair.Key.GetHashCode(), pair.Value.GetHashCode());
        }
        return keyBuilder.ToString();
    }
}

以上代码是对http://blog.stevensanderson.com/2008/10/15/partial-output-caching-in-aspnet-mvc/

的修改

缓存对Html.Action的调用

1 个答案: