Question

似乎有一千人在堆栈溢出时问了同样的问题，但似乎没有一个解决这个问题的方法。我要再问一次......

我有一个API控制器，它具有以下操作：

    // GET api/Exploitation
    public HttpResponseMessage Get() {
        var items = _exploitationRepository.FindAll();

        var mappedItems = Mapper.Map<IEnumerable<Exploitation>, IEnumerable<ExploitationView>>(items);

        var response = Request.CreateResponse<IEnumerable<ExploitationView>>(HttpStatusCode.OK, mappedItems);
        response.Headers.Location = new Uri(Url.Link("DefaultApi", new { }));
        return response;
    }

    // GET api/Exploitation/5        
    [HttpGet, ActionName("Get")]
    public HttpResponseMessage Get(int id) {
        var item = _exploitationRepository.FindById(id);
        var mappedItem = Mapper.Map<Exploitation, ExploitationView>(item);

        var response = Request.CreateResponse<ExploitationView>(HttpStatusCode.OK, mappedItem);
        response.Headers.Location = new Uri(Url.Link("DefaultApi", new { id = id }));
        return response;
    }

    // GET api/Exploitation/GetBySongwriterId/5
    [HttpGet, ActionName("GetBySongwriterId")]
    public HttpResponseMessage GetBySongwriterId(int id) {
        var item = _exploitationRepository.Find(e => e.Song.SongWriterSongs.Any(s => s.SongWriterId == id))
                                          .OrderByDescending(e => e.ReleaseDate);
        var mappedItem = Mapper.Map<IEnumerable<Exploitation>, IEnumerable<ExploitationView>>(item);

        var response = Request.CreateResponse<IEnumerable<ExploitationView>>(HttpStatusCode.OK, mappedItem);
        response.Headers.Location = new Uri(Url.Link("DefaultApi", new { id = id }));
        return response;
    }

    // GET api/Exploitation/GetBySongwriterId/5
    [HttpGet, ActionName("GetBySongId")]
    public HttpResponseMessage GetBySongId(int id) {
        var item = _exploitationRepository.Find(e => e.SongId == id)
                                          .OrderByDescending(e => e.ReleaseDate);
        var mappedItem = Mapper.Map<IEnumerable<Exploitation>, IEnumerable<ExploitationView>>(item);

        var response = Request.CreateResponse<IEnumerable<ExploitationView>>(HttpStatusCode.OK, mappedItem);
        response.Headers.Location = new Uri(Url.Link("DefaultApi", new { id = id }));
        return response;
    }

在我的APIConfig中，我定义了以下路线：

        config.Routes.MapHttpRoute(
            name: "DefaultApi",
            routeTemplate: "api/{controller}/{id}",
            defaults: new { id = RouteParameter.Optional }
        );

        config.Routes.MapHttpRoute(
            name: "ActionApi",
            routeTemplate: "api/{controller}/{action}/{id}",
            defaults: new { id = RouteParameter.Optional, action = RouteParameter.Optional },
            constraints: new { id = @"\d+" }
        );

我发现我可以访问以下操作没问题： / API /开发 / API /开发/ getbysongwriterid / 1 / API /开发/ getbysongid / 1

当我尝试访问/ api / exploit / 1时，我得到了这个异常

"Multiple actions were found that match the request: System.Net.Http.HttpResponseMessage Get(Int32) on type Songistry.API.ExploitationController System.Net.Http.HttpResponseMessage GetBySongwriterId(Int32)" exception.

有人能看出我的路线有什么问题吗？或其他别的错误？

Answer 1

我找到了一个优雅的解决方案。

我将ApiRouteConfig修改为具有以下路线：

        config.Routes.MapHttpRoute(
            name: "DefaultGetApi",
            routeTemplate: "api/{controller}/{id}",
            defaults: new { id = RouteParameter.Optional, action = "Get" },
            constraints: new { id = @"\d+", httpMethod = new HttpMethodConstraint(HttpMethod.Get) }
        );

        config.Routes.MapHttpRoute(
            name: "DefaultApi",
            routeTemplate: "api/{controller}/{id}",
            defaults: new { id = RouteParameter.Optional },
            constraints: new { id = @"\d+" }
        );            

        config.Routes.MapHttpRoute(
            name: "ActionApi",
            routeTemplate: "api/{controller}/{action}/{id}",
            defaults: new { id = RouteParameter.Optional, action = RouteParameter.Optional }
        );

现在我可以访问：

/api/exploitation
/api/exploitation/1
/api/exploitation/getbysongid/1
/api/exploitation/getbysongwriterid/1

我根本不需要修改我的控制器操作来使用这个新的路由配置。

如果你有多个PUT或POST动作，你可以创建如下所示的新路线：

    config.Routes.MapHttpRoute(
        name: "DefaultGetApi",
        routeTemplate: "api/{controller}/{id}",
        defaults: new { id = RouteParameter.Optional, action = "Put" },
        constraints: new { id = @"\d+", httpMethod = new HttpMethodConstraint(HttpMethod.Put) }
    );

    config.Routes.MapHttpRoute(
        name: "DefaultGetApi",
        routeTemplate: "api/{controller}/{id}",
        defaults: new { id = RouteParameter.Optional, action = "Delete" },
        constraints: new { id = @"\d+", httpMethod = new HttpMethodConstraint(HttpMethod.Delete) }
    );

我希望这个答案可以帮助每个人，因为这似乎是人们常见的问题。

Answer 2

您遇到的问题是 / api / exploit / 1 属于：

    config.Routes.MapHttpRoute(
        name: "DefaultApi",
        routeTemplate: "api/{controller}/{id}",
        defaults: new { id = RouteParameter.Optional }
    );

所有GET方法都满足该路由，特别是因为 {id} 是可选的，并且它们的控制器是相同的。

所以你有一个来自客户端的HTTP GET请求和多个接受GET请求的方法。它不知道要去哪一个。

api/{controller}/{action}/{id} 
//This works fine because you specified which action explicitly

我希望能回答你的问题。

Answer 3

在路线定义中尝试以下操作。只保留以下路线：

  config.Routes.MapHttpRoute(
        name: "ActionApi",
        routeTemplate: "api/{controller}/{action}/{id}",
        defaults: new { id = RouteParameter.Optional, action = "Get" },
        constraints: new { id = @"\d+" }
    );

将第一个Get方法设为私有，修改第二个方法，使id具有默认值：

// GET api/Exploitation
private HttpResponseMessage Get() {
    // implementation stays the same but now it's private
}

// GET api/Exploitation/5        
[HttpGet, ActionName("Get")]
public HttpResponseMessage Get(int id = 0) {
    if (id == 0) {
        return Get();
    }

    // continue standard implementation
}

这种方式（我自己没有测试过）我希望：

api / Exploitation /将映射到api / Exploitation / Get（默认操作），id = 0作为默认参数
api / Exploitation / 1将映射到api / Exploitation / Get / 1，因此它将调用Get（1）
api / Exploitation / someOtherAction / 345将调用正确的操作方法

这可能有用。更严格的路线定义实际上可能是这样的：

  config.Routes.MapHttpRoute(
        name: "ApiWithRequiredId",
        routeTemplate: "api/{controller}/{action}/{id}",
        defaults: null /* make sure we have explicit action and id */,
        constraints: new { id = @"\d+" }
    );

  config.Routes.MapHttpRoute(
        name: "ApiWithOptionalId",
        routeTemplate: "api/{controller}/{action}/{id}",
        defaults: new { id = RouteParameter.Optional, action = "Get" },
        constraints: new { action = "Get" /* only allow Get method to work with an optional id */, id = @"\d+" }
    );

但是这些方面的东西......尝试一下我希望它能解决你的问题。

存在多个获取操作时的MVC API路由

3 个答案: