Asp.net mvc 缺少可选参数时出现带区域-404的WebAPI路由错误

当我尝试在没有可选参数的情况下调用WebAPI控制器时，遇到了404错误。我尝试在Global.asax.cs中重新排序路由初始化命令，但没有成功。WebAPI在一个区域中，我注释了该区域的路由信息，因此它找不到该路由。以下是我所拥有的：

在WebApiConfig.cs中：

        public static void Register(HttpConfiguration configuration)
    {
        configuration.Routes.MapHttpRoute("DefaultAPI",
            "API/{controller}/{action}/{id}",
            new { id = RouteParameter.Optional });

        // From http://weblogs.asp.net/fbouma/how-to-make-asp-net-webapi-serialize-your-llblgen-pro-entities-to-json
        var json = configuration.Formatters.JsonFormatter;
        json.SerializerSettings.PreserveReferencesHandling = Newtonsoft.Json.PreserveReferencesHandling.Objects;
        json.SerializerSettings.ContractResolver = new DefaultContractResolver()
        {
            IgnoreSerializableInterface = true,
            IgnoreSerializableAttribute = true
        };

        var appXmlType = configuration.Formatters.XmlFormatter.SupportedMediaTypes.FirstOrDefault(t => t.MediaType == "application/xml");
        configuration.Formatters.XmlFormatter.SupportedMediaTypes.Remove(appXmlType);
    }

        public override void RegisterArea(AreaRegistrationContext context)
    {
        //context.MapRoute(
        //    "API_default",
        //    "API/{controller}/{action}/{id}",
        //    new { action = "Index", id = UrlParameter.Optional }
        //);
    }

        protected void Application_Start()
    {
        AreaRegistration.RegisterAllAreas();
        GlobalConfiguration.Configure(WebApiConfig.Register); 
        //WebApiConfig.Register(GlobalConfiguration.Configuration); 
        WebApiConfig.RegisterSiteMap();

        RouteConfig.RegisterRoutes(RouteTable.Routes);
    }

        [HttpGet]
    public IEnumerable<LocationFilterViewModel> GetLocations(int? id)
    {
        LocationFilterCollection Locations = LocationFilterCollection.GetLocations(id.HasValue ? id.Value : 0);
        List<LocationFilterViewModel> myList = new List<LocationFilterViewModel>();
        foreach (LocationFilterEntity myEntity in Locations)
        {
            LocationFilterViewModel myModel = new LocationFilterViewModel();
            InitializeModel(myEntity, myModel);
            myList.Add(myModel);
        }
        return myList;
    }

@Html.Kendo().TreeView().Name("Locations").LoadOnDemand(false).DataTextField("LocationName").DragAndDrop(false).Checkboxes(true).AutoBind(true).ExpandAll(true).DataSource(dataSource => dataSource
.Model(model => model
.Id("LocationId")
.HasChildren("HasChildren"))
.Read(read => read.Url(@Url.HttpRouteUrl("DefaultAPI", new { controller="LocationFilterAPI", action="GetLocations" }))))

在APIAreaRegistration.cs:

        public static void Register(HttpConfiguration configuration)
    {
        configuration.Routes.MapHttpRoute("DefaultAPI",
            "API/{controller}/{action}/{id}",
            new { id = RouteParameter.Optional });

        // From http://weblogs.asp.net/fbouma/how-to-make-asp-net-webapi-serialize-your-llblgen-pro-entities-to-json
        var json = configuration.Formatters.JsonFormatter;
        json.SerializerSettings.PreserveReferencesHandling = Newtonsoft.Json.PreserveReferencesHandling.Objects;
        json.SerializerSettings.ContractResolver = new DefaultContractResolver()
        {
            IgnoreSerializableInterface = true,
            IgnoreSerializableAttribute = true
        };

        var appXmlType = configuration.Formatters.XmlFormatter.SupportedMediaTypes.FirstOrDefault(t => t.MediaType == "application/xml");
        configuration.Formatters.XmlFormatter.SupportedMediaTypes.Remove(appXmlType);
    }

        public override void RegisterArea(AreaRegistrationContext context)
    {
        //context.MapRoute(
        //    "API_default",
        //    "API/{controller}/{action}/{id}",
        //    new { action = "Index", id = UrlParameter.Optional }
        //);
    }

        protected void Application_Start()
    {
        AreaRegistration.RegisterAllAreas();
        GlobalConfiguration.Configure(WebApiConfig.Register); 
        //WebApiConfig.Register(GlobalConfiguration.Configuration); 
        WebApiConfig.RegisterSiteMap();

        RouteConfig.RegisterRoutes(RouteTable.Routes);
    }

        [HttpGet]
    public IEnumerable<LocationFilterViewModel> GetLocations(int? id)
    {
        LocationFilterCollection Locations = LocationFilterCollection.GetLocations(id.HasValue ? id.Value : 0);
        List<LocationFilterViewModel> myList = new List<LocationFilterViewModel>();
        foreach (LocationFilterEntity myEntity in Locations)
        {
            LocationFilterViewModel myModel = new LocationFilterViewModel();
            InitializeModel(myEntity, myModel);
            myList.Add(myModel);
        }
        return myList;
    }

@Html.Kendo().TreeView().Name("Locations").LoadOnDemand(false).DataTextField("LocationName").DragAndDrop(false).Checkboxes(true).AutoBind(true).ExpandAll(true).DataSource(dataSource => dataSource
.Model(model => model
.Id("LocationId")
.HasChildren("HasChildren"))
.Read(read => read.Url(@Url.HttpRouteUrl("DefaultAPI", new { controller="LocationFilterAPI", action="GetLocations" }))))

在Global.asax.cs中：

        public static void Register(HttpConfiguration configuration)
    {
        configuration.Routes.MapHttpRoute("DefaultAPI",
            "API/{controller}/{action}/{id}",
            new { id = RouteParameter.Optional });

        // From http://weblogs.asp.net/fbouma/how-to-make-asp-net-webapi-serialize-your-llblgen-pro-entities-to-json
        var json = configuration.Formatters.JsonFormatter;
        json.SerializerSettings.PreserveReferencesHandling = Newtonsoft.Json.PreserveReferencesHandling.Objects;
        json.SerializerSettings.ContractResolver = new DefaultContractResolver()
        {
            IgnoreSerializableInterface = true,
            IgnoreSerializableAttribute = true
        };

        var appXmlType = configuration.Formatters.XmlFormatter.SupportedMediaTypes.FirstOrDefault(t => t.MediaType == "application/xml");
        configuration.Formatters.XmlFormatter.SupportedMediaTypes.Remove(appXmlType);
    }

        public override void RegisterArea(AreaRegistrationContext context)
    {
        //context.MapRoute(
        //    "API_default",
        //    "API/{controller}/{action}/{id}",
        //    new { action = "Index", id = UrlParameter.Optional }
        //);
    }

        protected void Application_Start()
    {
        AreaRegistration.RegisterAllAreas();
        GlobalConfiguration.Configure(WebApiConfig.Register); 
        //WebApiConfig.Register(GlobalConfiguration.Configuration); 
        WebApiConfig.RegisterSiteMap();

        RouteConfig.RegisterRoutes(RouteTable.Routes);
    }

        [HttpGet]
    public IEnumerable<LocationFilterViewModel> GetLocations(int? id)
    {
        LocationFilterCollection Locations = LocationFilterCollection.GetLocations(id.HasValue ? id.Value : 0);
        List<LocationFilterViewModel> myList = new List<LocationFilterViewModel>();
        foreach (LocationFilterEntity myEntity in Locations)
        {
            LocationFilterViewModel myModel = new LocationFilterViewModel();
            InitializeModel(myEntity, myModel);
            myList.Add(myModel);
        }
        return myList;
    }

@Html.Kendo().TreeView().Name("Locations").LoadOnDemand(false).DataTextField("LocationName").DragAndDrop(false).Checkboxes(true).AutoBind(true).ExpandAll(true).DataSource(dataSource => dataSource
.Model(model => model
.Id("LocationId")
.HasChildren("HasChildren"))
.Read(read => read.Url(@Url.HttpRouteUrl("DefaultAPI", new { controller="LocationFilterAPI", action="GetLocations" }))))

（请注意：我试过使用注释掉的行和上面的行，没有区别）

这是我的问题控制器：

        public static void Register(HttpConfiguration configuration)
    {
        configuration.Routes.MapHttpRoute("DefaultAPI",
            "API/{controller}/{action}/{id}",
            new { id = RouteParameter.Optional });

        // From http://weblogs.asp.net/fbouma/how-to-make-asp-net-webapi-serialize-your-llblgen-pro-entities-to-json
        var json = configuration.Formatters.JsonFormatter;
        json.SerializerSettings.PreserveReferencesHandling = Newtonsoft.Json.PreserveReferencesHandling.Objects;
        json.SerializerSettings.ContractResolver = new DefaultContractResolver()
        {
            IgnoreSerializableInterface = true,
            IgnoreSerializableAttribute = true
        };

        var appXmlType = configuration.Formatters.XmlFormatter.SupportedMediaTypes.FirstOrDefault(t => t.MediaType == "application/xml");
        configuration.Formatters.XmlFormatter.SupportedMediaTypes.Remove(appXmlType);
    }

        public override void RegisterArea(AreaRegistrationContext context)
    {
        //context.MapRoute(
        //    "API_default",
        //    "API/{controller}/{action}/{id}",
        //    new { action = "Index", id = UrlParameter.Optional }
        //);
    }

        protected void Application_Start()
    {
        AreaRegistration.RegisterAllAreas();
        GlobalConfiguration.Configure(WebApiConfig.Register); 
        //WebApiConfig.Register(GlobalConfiguration.Configuration); 
        WebApiConfig.RegisterSiteMap();

        RouteConfig.RegisterRoutes(RouteTable.Routes);
    }

        [HttpGet]
    public IEnumerable<LocationFilterViewModel> GetLocations(int? id)
    {
        LocationFilterCollection Locations = LocationFilterCollection.GetLocations(id.HasValue ? id.Value : 0);
        List<LocationFilterViewModel> myList = new List<LocationFilterViewModel>();
        foreach (LocationFilterEntity myEntity in Locations)
        {
            LocationFilterViewModel myModel = new LocationFilterViewModel();
            InitializeModel(myEntity, myModel);
            myList.Add(myModel);
        }
        return myList;
    }

@Html.Kendo().TreeView().Name("Locations").LoadOnDemand(false).DataTextField("LocationName").DragAndDrop(false).Checkboxes(true).AutoBind(true).ExpandAll(true).DataSource(dataSource => dataSource
.Model(model => model
.Id("LocationId")
.HasChildren("HasChildren"))
.Read(read => read.Url(@Url.HttpRouteUrl("DefaultAPI", new { controller="LocationFilterAPI", action="GetLocations" }))))

如果在action=语句之后添加id=0，它将不再返回404错误，而是继续返回0节点，而不是返回当前节点的子节点。如果省略id=0，则返回404错误，即

/API/LocationFilterAPI/GetLocations/0-工作正常

/API/LocationFilterAPI/GetLocations-返回404

我在这个控制器中的其他每个API调用要么有一个必需的参数，要么根本没有参数，所有这些都工作得很好。整个下午我都在忙这个。如有任何见解，将不胜感激

谢谢

劳里

p、 下面是我的RegisterRoutes方法，以回应评论：

        public static void RegisterRoutes(RouteCollection routes)
    {
        routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

        routes.MapRoute(
            name: "LibraryCategoryList",
            url: "Library/List/{id}/{id2}",
            defaults: new { controller = "Library", action = "List", id = UrlParameter.Optional,id2=UrlParameter.Optional }
            );
        routes.MapRoute(
            name: "Default",
            url: "{controller}/{action}/{id}",
            defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional },
            namespaces: new[] { "BFRDP.Controllers" }
        );
    }

---

尝试为方法参数

指定一个空值，表示该参数是可选的

public IEnumerable<LocationFilterViewModel> GetLocations(int? id = null)

public IEnumerable GetLocations（int？id=null）

尝试为方法参数

指定一个空值，表示该参数是可选的

public IEnumerable<LocationFilterViewModel> GetLocations(int? id = null)

public IEnumerable GetLocations（int？id=null）

我猜如果末尾没有参数，它会将

GetLocations

作为其他路由的参数。您的

应用程序\u Start

也在注册MVC路由-您只显示了API路由。其他路由是什么样子的？我猜如果没有末尾的参数，它会将

GetLocations

作为其他路由的参数。您的

应用程序\u Start

也在注册MVC路由-您只显示了API路由。其他路线是什么样子的？