我无法访问我在现有项目中创建的新 Web API controller

Question

In an existing ASP.NET MVC project, I've created a new Web API controller.

namespace EMSMVC.Controllers
{
    public class TabletController : ApiController
    {
        public Call Get(int call_id)
        {
            using(EMSMVCEntities entities = new EMSMVCEntities())
            {
                return entities.Calls.FirstOrDefault(e => e.call_id == call_id);
            }
        }
    }
}

When I'm trying to access it via browser using:

http://localhost:53366/Tablet/Call/157

I get the error:

Server Error in '/'Application. The resource cannot be found.

My RouteConfig.cs contains:

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

        routes.MapRoute(
            name: "Default",
            url: "{controller}/{action}/{id}",
            defaults: new { controller = "Dashboard", action = "Index", id = UrlParameter.Optional }
        );
    }
}

The WebApiConfig.cs file contains:

public static class WebApiConfig
{
    public static void Register(HttpConfiguration config)
    {
        // Web API configuration and services

        // Web API routes
        config.MapHttpAttributeRoutes();

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

The existing controllers are working properly.

Answer 1

Can you please change the action signature as [HttpGet] public Call Get(int id) and access as localhost:53366/api/Tablet/157

When you encounter any serialization issues then Make sure both the serialization at "Call" model and "httpclient" in sync.

Please find more details about 'ObjectContent`1': Failed to serialize the response from DbSet

Answer 2

Try these two options:

Option 1. Use following URL:

http://localhost:53366/Tablet/Call?call_id=157

Option 2. Modify code like:

[RoutePrefix("tablet/services")]
public class TabletController : ApiController
{

    [Route("getcall")]
    [HttpGet, ActionName("getcall")]
    public Call Get(int call_id)
    {
        using (EMSMVCEntities entities = new EMSMVCEntities())
        {
            return entities.Calls.FirstOrDefault(e => e.call_id == call_id);
        }
    }
}

and then try to call it with following URL:

http://localhost:53366/tablet/services/getcall/157

OR

http://localhost:53366/tablet/services/getcall?call_id=157

Answer 3

In {controller}/{action}/{id} , {action} is the method name, which in your controller is Get . In your url ( http://localhost:53366/Tablet/Call/157 ), you have Call , which is the return type of your method. Try navigating to http://localhost:53366/Tablet/Get/157

Answer 4

Please Try http://localhost:53366/Tablet/Get/157

if still not work keep add [HttpGet] like below

[HttpGet] public Call Get(int call_id)