从IOwinContext

Question

我希望从请求中获取路由模板。我正在使用OwinMiddleware并重写接受IOwinContext的Invoke方法。

public override async Task Invoke(IOwinContext context)
{
    ...
}

根据请求网址：http://api.mycatservice.com/Cats/1234

我想得到＆＃34; Cats / {CatId} ＆＃34;

我尝试使用以下方法转换它失败了：

HttpRequestMessage msg = new HttpRequestMessage(new HttpMethod(context.Request.Method), context.Request.Uri);

HttpContextBase httpContext = context.Get<HttpContextBase>(typeof(HttpContextBase).FullName);

供参考：

这是我为另一个项目成功实施的post about how to do this using HttpRequestMessage

Answer 1

我有同样的问题，这似乎有效。有点神奇，但到目前为止一直很好：

public class RouteTemplateMiddleware : OwinMiddleware
{
    private const string HttpRouteDataKey = "MS_SubRoutes";
    private readonly HttpRouteCollection _routes;

    public RouteTemplateMiddleware(OwinMiddleware next, HttpRouteCollection routes) : base(next)
    {
        _routes = routes;
    }

    public override async Task Invoke(IOwinContext context)
    {
        var routeData = _routes.GetRouteData(new HttpRequestMessage(new HttpMethod(context.Request.Method), context.Request.Uri));
        var routeValues = routeData?.Values as System.Web.Http.Routing.HttpRouteValueDictionary;

        var route = routeValues?[HttpRouteDataKey] as System.Web.Http.Routing.IHttpRouteData[];
        var routeTemplate = route?[0].Route.RouteTemplate;

        // ... do something the route template

        await Next.Invoke(context);
    }
}

像这样注册中间件：

public void Configuration(IAppBuilder app)
{
    _httpConfiguration = new HttpConfiguration();
    _httpConfiguration.MapHttpAttributeRoutes();
    ...

    app.Use<RouteTemplateMiddleware>(_httpConfiguration.Routes);
    ...
}