Owin CORS Hack

gistfile1.cs

            return WebApp.Start(
                startOptions,
                app =>
                {
                    app.UseErrorPage();
                    app.Use(
                        new Func<AppFunc, AppFunc>(
                            ignoreNextApp => (env =>
                            {
                                var responseHeaders = (IDictionary<string, string[]>)env["owin.ResponseHeaders"];
                                responseHeaders.Add("Access-Control-Allow-Origin", new string[] { "*" });
                                return simpleWeb.Invoke(env);
                            })));
                });