问即使我启用了cors，PUT和DELETE请求在Web API 2中也不起作用

EN

public static class WebApiConfig
{
    public static void Register(HttpConfiguration config)
    {
        // Web API configuration and services
                 var cors = new EnableCorsAttribute("http://example.net", "*", "*");
                 config.EnableCors(cors);

        // Configure Web API to use only bearer token authentication.
                    config.SuppressDefaultHostAuthentication();
                    config.Filters.Add(new HostAuthenticationFilter(OAuthDefaults.AuthenticationType));

        // Web API routes
        config.MapHttpAttributeRoutes();

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