How to use Route attribute to bind query string with web API?

Question

I'm trying to get this to work:

[Route("api/Default")]
public class DefaultController : ApiController
{
    [HttpGet, Route("{name}")]
    public string Get(string name)
    {
        return $"Hello " + name;
    }
}

by calling this http://localhost:55539/api/Default?name=rami but not working, tried this also:http://localhost:55539/api/Default/Hello?name=rami , Also this not working: http://localhost:55539/api/Default/Hello/rami

Answer 1

Make sure attribute routing is enabled in WebApiConfig.cs

config.MapHttpAttributeroutes();

ApiController actions can have multiple routes assigned to them.

[RoutePrefix("api/Default")]
public class DefaultController : ApiController {

    [HttpGet]
    //GET api/Default
    //GET api/Default?name=John%20Doe
    [Route("")]
    //GET api/Default/John%20Doe
    [Route("{name}")]
    public string Get(string name) {
        return $"Hello " + name;
    }
}

There is also the option of making the parameter optional, which then allow you to call the URL with out the inline parameter and let the routing table use the query string similar to how it is done in convention-based routing.

[RoutePrefix("api/Default")]
public class DefaultController : ApiController {

    [HttpGet]
    //GET api/Default
    //GET api/Default?name=John%20Doe 
    //GET api/Default/John%20Doe
    [Route("{name?}")]
    public string Get(string name = null) {
        return $"Hello " + name;
    }
}

Answer 2

In Web API first route template matching happens and then the action selection process.

Your C# should be like this:

public class DefaultController : ApiController
{
    [HttpGet] 
    [Route("api/Default/{name}")]
    public string Get(string name)
    {
        return $"Hello " + name;
    }
}

Now call should be like this:

http://localhost:55539/api/Default/Get?name=rami