WCF Rest 4.0，动态路由和OutputCache

如何解决WCF Rest 4.0，动态路由和OutputCache

| 我在将OutputCaching与Output0ѭ一起用于WCF 4.0 WebHttp服务时遇到问题。 我的服务已本地化。想法是您这样调用URL：

/languageCode/ServiceName/Method
e.g.
/en/MyService/GetItems

它将返回本地化为正确语言的结果。 我的计划基于本文。这个想法是创建RouteBase的派生类，该派生类创建到真实服务的唯一“私有”路由。当用户发出请求时，语言代码会从URL中解压缩并设置为当前线程的区域性，然后使用“ 0”来加载实际的服务。 为了我的一生，我无法弄清楚如何将OutputCaching应用于混合。我已经用

AspNetCacheProfile

装饰了我的服务方法，并且看到了我自己的

varyByCustom

覆盖被调用。但是，尽管收到来自

varyByCustom

的重复结果，.NET仍然继续成为我的服务方法。 下面有很多代码，对转储感到抱歉，但我怀疑这一切都相关。 我如何在Global.asax.cs中添加路线

RouteTable.Routes.Add(new CulturedServiceRoute(
    \"devices\",new StructureMapServiceHostFactory(),typeof(DeviceService)));

Global.asax.cs中的varyByCustom覆盖：

public override string GetvaryByCustomString(
    HttpContext context,string custom)
{

    // This method gets called twice: Once for the initial request,then a 
    // second time for the rewritten URL. I only want it to be called once!

    if (custom == \"XmlDataFreshness\")
    {
        var outputString = String.Format(\"{0}|{1}|{2}\",XmlDataLoader.LastUpdatedTicks,context.Request.RawUrl,context.Request.HttpMethod);
        return outputString;
    }

    return base.GetvaryByCustomString(context,custom);
}

这是动态服务路由类。

public class CulturedServiceRoute : RouteBase,IRouteHandler
{
    private readonly string _virtualPath = null;
    private readonly ServiceRoute _innerServiceRoute = null;
    private readonly Route _innerRoute = null;

    public CulturedServiceRoute(
        string pathPrefix,ServiceHostFactoryBase serviceHostFactory,Type serviceType)
    {
        if (pathPrefix.IndexOf(\"{\") >= 0)
        {
            throw new ArgumentException(
                \"Path prefix cannot include route parameters.\",\"pathPrefix\");
        }
        if (!pathPrefix.StartsWith(\"/\")) pathPrefix = \"/\" + pathPrefix;
        pathPrefix = \"{culture}\" + pathPrefix;

        _virtualPath = String.Format(\"Cultured/{0}/\",serviceType.FullName);
        _innerServiceRoute = new ServiceRoute(
            _virtualPath,serviceHostFactory,serviceType);
        _innerRoute = new Route(pathPrefix,this);
    }

    public override RouteData GetRouteData(
        HttpContextBase httpContext)
    {
        return _innerRoute.GetRouteData(httpContext);
    }

    public override VirtualPathData GetVirtualPath(
        RequestContext requestContext,RouteValueDictionary values)
    {
        return null;
    }

    public IHttpHandler GetHttpHandler(RequestContext requestContext)
    {
        // This method is called even if varyByCustom 
        // returns a duplicate response!

        var culture = requestContext.RouteData.Values[\"culture\"].ToString();
        var ci = new CultureInfo(culture);
        Thread.CurrentThread.CurrentUICulture = ci;
        Thread.CurrentThread.CurrentCulture = 
            CultureInfo.CreateSpecificCulture(ci.Name);

        requestContext.HttpContext.RewritePath(\"~/\" + _virtualPath,true);
        return _innerServiceRoute.RouteHandler.GetHttpHandler(requestContext);
    }
}

最后，服务本身的相关部分：

[ServiceContract]
[AspNetCompatibilityRequirements(
    RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]
[ServiceBehavior(InstanceContextMode = InstanceContextMode.PerCall)]
public class DeviceService
{
    [AspNetCacheProfile(\"MyCacheProfile\")]
    [WebGet(UriTemplate = \"\")]
    public IEnumerable<DeviceListItemmodel> GetDevices()
    {
        // This is called AFTER the first varyByCustom override is called.
        // I\'d expect it not to be called unless varyByCustom changes!

        var devices =
            from d in _deviceRepository.GetAll()
            where d.ReleaseDate < DateTime.Now
            orderby d.Id descending
            select new DeviceListItemmodel(d);

        return devices;
    }

更新：我的缓存配置文件：

<caching>
  <outputCacheSettings>
    <outputCacheProfiles>
      <add name=\"MyCacheProfile\" varyByCustom=\"XmlDataFreshness\"
           varyByHeader=\"accept\" varyByParam=\"*\" location=\"Server\"
           duration=\"3600\" />
    </outputCacheProfiles>
  </outputCacheSettings>
</caching>

    

解决方法

        嗯，对我来说似乎是一种有效的方法。缓存配置文件是否配置正确？是否需要多次调用variableByCustom并确定在不需要更新缓存时会返回相同的结果？