C# – Multiple HttpPost method in Web API controller

asp.net-web-apiasp.net-web-api-routingc++global-asax

I am starting to use MVC4 Web API project, I have controller with multiple HttpPost methods. The Controller looks like the following:

Controller

public class VTRoutingController : ApiController
{
    [HttpPost]
    public MyResult Route(MyRequestTemplate routingRequestTemplate)
    {
        return null;
    }

    [HttpPost]
    public MyResult TSPRoute(MyRequestTemplate routingRequestTemplate)
    {
        return null;
    }
}

Here MyRequestTemplate represents the template class responsible for handling the Json coming through the request.

Error:

When I make a request using Fiddler for http://localhost:52370/api/VTRouting/TSPRoute or http://localhost:52370/api/VTRouting/Route I get an error:

Multiple actions were found that match the request

If I remove one of the above method it works fine.

Global.asax

I have tried modifying the default routing table in global.asax, but I am still getting the error, I think I have problem in defining routes in global.asax. Here is what I am doing in global.asax.

public static void RegisterRoutes(RouteCollection routes)
{
    routes.MapHttpRoute(
        name: "MyTSPRoute",
        routeTemplate: "api/VTRouting/TSPRoute",
        defaults: new { }
    );

    routes.MapHttpRoute(
        name: "MyRoute",
        routeTemplate: "api/VTRouting/Route",
        defaults: new { action="Route" }
    );
}

I am making the request in Fiddler using POST, passing json in RequestBody for MyRequestTemplate.

Best Solution

You can have multiple actions in a single controller.

For that you have to do the following two things.

  • First decorate actions with ActionName attribute like

     [ActionName("route")]
     public class VTRoutingController : ApiController
     {
       [ActionName("route")]
       public MyResult PostRoute(MyRequestTemplate routingRequestTemplate)
       {
         return null;
       }
    
      [ActionName("tspRoute")]
      public MyResult PostTSPRoute(MyRequestTemplate routingRequestTemplate)
      {
         return null;
      }
    }
    
  • Second define the following routes in WebApiConfig file.

    // Controller Only
    // To handle routes like `/api/VTRouting`
    config.Routes.MapHttpRoute(
        name: "ControllerOnly",
        routeTemplate: "api/{controller}"               
    );
    
    
    // Controller with ID
    // To handle routes like `/api/VTRouting/1`
    config.Routes.MapHttpRoute(
        name: "ControllerAndId",
        routeTemplate: "api/{controller}/{id}",
        defaults: null,
        constraints: new { id = @"^\d+$" } // Only integers 
    );
    
    // Controllers with Actions
    // To handle routes like `/api/VTRouting/route`
    config.Routes.MapHttpRoute(
        name: "ControllerAndAction",
        routeTemplate: "api/{controller}/{action}"
    );