No HTTP resource was found that matches the request URI in Web API

Question

I have configured my WebApiConfig like this:

public static void Register(HttpConfiguration config)
{
    config.Routes.MapHttpRoute(
        name: \"DefaultApi\"         


        

Answer 1

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

Maps to:

http://localhost:8598/api/Controller/Action/id

The WebApi portion of the url is redundant with api. Then modify the method parameter name to match the route:

public IEnumerable<LocationCategory_CLS> GetLocationCategory(int id)

This is a good default as it matches the convention.

Alternatively, you can modify the route to use this unconventional parameter name instead:

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

Finally, in either case make sure the controller name ends in Controller.

Good names: CustomController, CustomApiController
Bad names: Custom, CustomApi

Answer 2

Try changing your Controller method as

public IEnumerable<LocationCategory_CLS> GetLocationCategory(int id) <-- Change
{
    var LocCats = (from lct in entities.tdp_LocationCategories join lc in entities.tdp_LocationMaster on lct.FK_LocationID equals lc.LocationID where lct.IsApproved == 0 && lct.FK_CategoryID == id select new { lc.LocationID, lc.LocationName }).ToList();
    List<LocationCategory_CLS> loc = new List<LocationCategory_CLS>();

    foreach (var element in LocCats)
    {
        loc.Add(new LocationCategory_CLS
        {
            LocationID = element.LocationID,
            LocationName = element.LocationName
        });
    }
    return loc;
}

The change is only, changing input parameter from CatId to id.... It works for me many times..

Edit :

---

Its a long time when I look back I think I know the reason now. Words Like Jared is correct, it's all to do with Routing which we specify. If I have a route(default) as :

routes.MapRoute(
        "Default",                                              // Route name
        "{controller}/{action}/{id}",                           // URL with parameters
        new { controller = "Home", action = "Index", id = "" }  // Parameter defaults
    );

And my URL is /MyController/GetLocationCategory/123, it will be equivalent to /MyController/GetLocationCategory?id=123.

Similarly, if I want to change my parameter name for Id to say CatId, then I need to change the query string parameter(the way I am calling my Controller Action would change). Which would now be :

/MyController/GetLocationCategory?CatId=123

Answer 3

what is the name of your controller and action ?

The URL should be

http://localhost:8598/api/Controller/Action

It does not map to the Route Configuration you have specified, hence the pipeline is unable to locate the correct Controller. The /id should not be in the path it must be in the body or the query parameters ( I got stumped in haste !!)

Example : -

public class FooController : ApiController
    {
        public int GetIndex(int id)
        {
            return id;
        }
    }

localhost:58432/api/foo/GetIndex?Id=1

O/P :- 1

Note:- If your action name is GetIndex then the URL must be GetIndex not just Index. Optionally you can specify the [HttpGet] attribute for the action.

If you have the following as well in your WebApi.config

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

Then http://localhost:58432/api/foo?Id=1 would also be a legitimate route. Not sure if you would want that.

Also, With WebAPI as far as possible stick to non action based routing , MVC is meant for that. It is not the recommended way.

Answer 4

Your request URL is http://localhost:8598/api/WebApi/GetLocationCategory/87

Your route is configured to accept: 'api/{controller}/{action}/{id}'

So you need to ensure that the name of your controller is 'WebApiController'.

Also, as stated alredy by @SDG you need to make sure that the name of the parameter to your action method matches what you have in your Route template i.e change 'CatID' to 'id'