OData 和 Web API 路由冲突

Question

我有一个带有 WebAPI 控制器的项目。我现在正在向其中添加 OData 控制器。问题是我的 OData 控制器与现有的 WebAPI 控制器同名，这会导致异常：

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

即使控制器位于不同的命名空间并且应该具有可区分的路由，也会发生这种情况。这是我拥有的配置的摘要。我能做什么（除了重命名控制器）来防止这个异常？我正在尝试将这些端点公开为：

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

在我看来，URL 足够不同，必须有一些方法来配置路由，所以不会发生冲突。

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 中包含命名空间约束：

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"];

如果您遇到视图控制器冲突，您应该能够包含类似的命名空间约束：

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

如果您有两个具有相同名称和不同命名空间的控制器 api 和 OData 您可以使用此代码。首先添加这个类：

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));
    }
}

它驱动 DefaultHttpControllerSelector，你应该在 Register 方法的末尾添加这一行 WebApiConfig.cs 文件：

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

注意事项：

它使用控制器的命名空间来确定控制器是否为 OData。因此，您的 OData 控制器应该有 namespace YourProject.Controllers.OData，而对于 API 控制器，它不应在命名空间中包含 OData 字。

感谢Martin Devillers 的帖子。我使用了他的想法和他的一段代码！