The requested resource does not support HTTP method 'GET'

Question

My route is correctly configured, and my methods have the decorated tag. I still get "The requested resource does not support HTTP method 'GET'" message?

[System.Web.Mvc.AcceptVerbs("GET", "POST")] [System.Web.Mvc.HttpGet] public string Auth(string username, string password) {   // Décoder les paramètres reçue.   string decodedUsername = username.DecodeFromBase64();   string decodedPassword = password.DecodeFromBase64();    return "value"; } 

Here are my routes:

config.Routes.MapHttpRoute(     name: "AuthentificateRoute",     routeTemplate: "api/game/authentificate;{username};{password}",     defaults: new { controller = "Game",                     action = "Auth",                      username = RouteParameter.Optional,                      password = RouteParameter.Optional },     constraints: new { httpMethod = new HttpMethodConstraint(HttpMethod.Get) } );  config.Routes.MapHttpRoute(     name: "DefaultApi",     routeTemplate: "api/{controller}/{id}",     defaults: new { controller = "Home", id = RouteParameter.Optional } ); 

Answer 1

Please use the attributes from the System.Web.Http namespace on your WebAPI actions:

    [System.Web.Http.AcceptVerbs("GET", "POST")]     [System.Web.Http.HttpGet]     public string Auth(string username, string password)     {...} 

The reason why it doesn't work is because you were using the attributes that are from the MVC namespace System.Web.Mvc. The classes in the System.Web.Http namespace are for WebAPI.