OData和WebAPI路由沖突

Question

我有一個帶有WebAPI控制器的項目。 我現在正在添加OData控制器。 問題是我的OData控制器與現有的WebAPI控制器具有相同的名稱，這導致異常：

Multiple types were found that match the controller named 'Member'. This can happen if the route that services this request ('OData/{*odataPath}') found multiple controllers defined with the same name but differing namespaces, which is not supported. The request for 'Member' has found the following matching controllers: Foo.Bar.Web.Areas.API.Controllers.MemberController Foo.Bar.Web.Odata.Controllers.MemberController

即使控制器位於不同的名稱空間並且應該具有可區分的路由，也會發生這種情況。 以下是我所擁有的配置的摘要。 我該怎么做（除了重命名控制器）以防止此異常？ 我正在嘗試將這些端點公開為：

mysite.com/OData/Members
mysite.com/API/Members/EndPoint

在我看來，URL足夠明顯，必須有一些方法來配置路由，所以沒有沖突。

namespace Foo.Bar.Web.Odata.Controllers {

    public class MemberController : ODataController {
        [EnableQuery]
        public IHttpActionResult Get() {
            // ... do stuff with EF ...
        }
    }
}

namespace Foo.Bar.Web.Areas.API.Controllers {

    public class MemberController : ApiControllerBase {
        [HttpPost]
        public HttpResponseMessage EndPoint(SomeModel model) {
            // ... do stuff to check email ...
        }
    }
}

public class FooBarApp : HttpApplication {

    protected void Application_Start () {
        // ... snip ...

        GlobalConfiguration.Configure(ODataConfig.Register);
        AreaRegistration.RegisterAllAreas();
        RouteConfig.RegisterRoutes(RouteTable.Routes);

        // ... snip ...
    }
}

public static class ODataConfig {
    public static void Register(HttpConfiguration config) {
        config.MapODataServiceRoute(
            routeName: "ODataRoute",
            routePrefix: "OData",
            model: GetModel());
    }

    public static Microsoft.OData.Edm.IEdmModel GetModel() {
        // ... build edm models ...
    }
}

namespace Foo.Bar.Web.Areas.API {
    public class APIAreaRegistration : AreaRegistration {
        public override string AreaName {
            get { return "API"; }
        }

        public override void RegisterArea(AreaRegistrationContext context) {
            var route = context.Routes.MapHttpRoute(
                "API_default",
                "API/{controller}/{action}/{id}",
                new { action = RouteParameter.Optional, id = RouteParameter.Optional }
            );
        }
    }
}

Answer 1

您需要在WebAPI上包含名稱空間約束：

var route = context.Routes.MapHttpRoute(
            name: "API_default",
            routeTemplate: "API/{controller}/{action}/{id}",
            defaults:new { action = RouteParameter.Optional, id = RouteParameter.Optional },
        );
route.DataTokens["Namespaces"] = new string[] {"Foo.Bar.Web.Areas.API.Controllers"];

如果您遇到視圖控制器的沖突，您應該能夠包含類似的命名空間約束：

routes.MapRoute(
            name: "ViewControllers_Default",
            url: "{controller}/{action}/{id}",
            defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional, area = "" },
            namespaces: new[]{"Foo.Bar.Web.Controllers"}
        );

Answer 2

如果有兩個控制器具有相同的名稱和api和OData不同命名空間，則可以使用此代碼。 首先添加這個類：

public class ODataHttpControllerSelector : DefaultHttpControllerSelector
{
    private readonly HttpConfiguration _configuration;
    private readonly Lazy<ConcurrentDictionary<string, Type>> _apiControllerTypes;

    public ODataHttpControllerSelector(HttpConfiguration configuration)
        : base(configuration)
    {
        _configuration = configuration;
        _apiControllerTypes = new Lazy<ConcurrentDictionary<string, Type>>(GetControllerTypes);
    }

    public override HttpControllerDescriptor SelectController(HttpRequestMessage request)
    {
        return this.GetApiController(request);
    }

    private static ConcurrentDictionary<string, Type> GetControllerTypes()
    {
        var assemblies = AppDomain.CurrentDomain.GetAssemblies();

        var types = assemblies
            .SelectMany(a => a
                .GetTypes().Where(t =>
                    !t.IsAbstract &&
                    t.Name.EndsWith(ControllerSuffix, StringComparison.OrdinalIgnoreCase) &&
                    typeof(IHttpController).IsAssignableFrom(t)))
            .ToDictionary(t => t.FullName, t => t);

        return new ConcurrentDictionary<string, Type>(types);
    }

    private HttpControllerDescriptor GetApiController(HttpRequestMessage request)
    {
        var isOData = IsOData(request);
        var controllerName = GetControllerName(request);
        var type = GetControllerType(isOData, controllerName);

        return new HttpControllerDescriptor(_configuration, controllerName, type);
    }

    private static bool IsOData(HttpRequestMessage request)
    {
        var data = request.RequestUri.ToString();
        bool match = data.IndexOf("/OData/", StringComparison.OrdinalIgnoreCase) >= 0 ||
            data.EndsWith("/OData", StringComparison.OrdinalIgnoreCase);
        return match;
    }

    private Type GetControllerType(bool isOData, string controllerName)
    {
        var query = _apiControllerTypes.Value.AsEnumerable();

        if (isOData)
        {
            query = query.FromOData();
        }
        else
        {
            query = query.WithoutOData();
        }

        return query
            .ByControllerName(controllerName)
            .Select(x => x.Value)
            .Single();
    }
}

public static class ControllerTypeSpecifications
{
    public static IEnumerable<KeyValuePair<string, Type>> FromOData(this IEnumerable<KeyValuePair<string, Type>> query)
    {
        return query.Where(x => x.Key.IndexOf(".OData.", StringComparison.OrdinalIgnoreCase) >= 0);
    }

    public static IEnumerable<KeyValuePair<string, Type>> WithoutOData(this IEnumerable<KeyValuePair<string, Type>> query)
    {
        return query.Where(x => x.Key.IndexOf(".OData.", StringComparison.OrdinalIgnoreCase) < 0);
    }

    public static IEnumerable<KeyValuePair<string, Type>> ByControllerName(this IEnumerable<KeyValuePair<string, Type>> query, string controllerName)
    {
        var controllerNameToFind = string.Format(CultureInfo.InvariantCulture, ".{0}{1}", controllerName, DefaultHttpControllerSelector.ControllerSuffix);

        return query.Where(x => x.Key.EndsWith(controllerNameToFind, StringComparison.OrdinalIgnoreCase));
    }
}

它驅動DefaultHttpControllerSelector ，你應該在WebApiConfig.cs文件中的Register方法的末尾添加這一行：

config.Services.Replace(typeof(IHttpControllerSelector), new ODataHttpControllerSelector(config));

筆記：

它使用控制器的命名空間來確定控制器是否為OData。 因此，您應該為OData控制器設置namespace YourProject.Controllers.OData ，而對於API控制器，它不應該包含命名空間中的OData字。

感謝Martin Devillers的發帖。 我用他的想法和他的代碼！