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

Try changing your Controller method as

public IEnumerable 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 loc = new List();

    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