Web Api 2 API无法识别路由的多个属性（版本控制）

Question

I'm trying to implement both Attribute Routing and the VersionedRoute from RoutingConstaints Sample but when I use both on a controller, the versioned attribute no longer works.

What would I need to modify on the attribute to get it to play nice with Attribute Routing?

For code example download the sample project (or just look at the few files from the above link) and then modify the routes as such:

// When I use the RoutePrefix, VersionedRoute no longer works (Sending "Api-Version" through http header doesn't route correctly
// If I remove the RoutePrefix I can use VersionedRoute again
// What do I need to change in its code to be able to use both?

[VersionedRoute("api/Customers", 1)] // This route would be used as http://url/api/customers with a header of "api-version: 1"
[RoutePrefix("api/v1/Customers")] // This route would be used purely through url versioning of http://url/api/v1/Customers
public class CustomersV1Controller : ApiController {

    /* Other stuff removed */

    [VersionedRoute("api/Customer", 1)] // I'd rather not have to use this here at all and just use a single one on the class, but having both nor just one on either works right now.
    [Route("")]
    public IHttpActionResult Get()
    {
        return Json(_customers);
    }
}

VersionedRoute Code

VersionConstraint Code

Edit: Please let me know if you need more information or even post ideas or things to try :)

Edit2: Here is an example of what I'm trying to do from Troy Hunt's Blog: http://www.troyhunt.com/2014/02/your-api-versioning-is-wrong-which-is.html

Edit3: Here is what I'd like to code to be as close to since it would reduce a lot of the overhead and magic strings.

[VersionedRoute("api/Customers", 1)] // This route would be used as http://url/api/customers with a header of "api-version: 1"
[RoutePrefix("api/v1/Customers")] // This route would be used purely through url versioning of http://url/api/v1/Customers
public class CustomersV1Controller : ApiController {

    /* Other stuff removed */
    [Route("")]
    public IHttpActionResult Get()
    {
        // Removed
        return Ok(customers);
    }


    [Route("{id:int}")]
    public IHttpActionResult GetById(int id)
    {
        // Removed
        return Ok(customer);
    }
}

[VersionedRoute("api/Customers", 2)] // This route would be used as http://url/api/customers with a header of "api-version: 2"
[RoutePrefix("api/v2/Customers")] // This route would be used purely through url versioning of http://url/api/v2/Customers
public class CustomersV2Controller : ApiController {

    /* Other stuff removed */
    [Route("")]
    public IHttpActionResult Get()
    {
        // Removed
        return Ok(customersThatAreDifferentThanV1);
    }


    [Route("{id:int}")]
    public IHttpActionResult GetById(int id)
    {
        // Removed
        return Ok(customerThatIsDifferent);
    }
}

Edit: Last bump, trying to only have to write the route version information once per route, at the controller attribute level and not per-action.

Answer 1

The Route and VersionedRoute attributes are working fine together, but your RoutePrefix attribute is also applied to your VersionedRoute (try accessing /api/v1/Customers/api/Customer - you'll get a response when the api-version header is set)

The following code would produce the desired behaviour with regards to the two URLs in your example returning the correct responses, but obviously this does not solve your problem of wanting one VersionedRoute and one RoutePrefix at the top of the class. Another approach would be needed for this. You can, however, have separate controllers for different api versions.

[RoutePrefix("api")]
public class CustomersV1Controller : ApiController
{
    /* Other stuff removed */

    [VersionedRoute("Customers", 1)]
    [Route("v1/Customers")]
    public IHttpActionResult Get()
    {
        return Json(_customers);
    }
}

An improvement would be to create your own attribute instead of Route so you wouldn't need to prefix the version every time:

public class CustomVersionedRoute : Attribute, IHttpRouteInfoProvider
{
    private readonly string _template;

    public CustomVersionedRoute(string route, int version)
    {
        _template = string.Format("v{0}/{1}", version, route);
    }

    public string Name { get { return _template; } }
    public string Template { get { return _template ; } }
    public int Order { get; set; }
}

[RoutePrefix("api")]
public class CustomersV2Controller : ApiController
{
    /* Other stuff removed */

    [VersionedRoute("Customers", 2)]
    [CustomVersionedRoute("Customers", 2)]
    public IHttpActionResult Get()
    {
        return Json(_customers);
    }
}