public void InviteFriends(OnRequestDelegate callback) { if (callback != null) { this.InviteFriendsCB = callback; } Lang lang = Service.Lang; string message = lang.Get("FB_INVITE_MESSAGE", new object[0]); string title = lang.Get("FB_INVITE_TITLE", new object[0]); FacebookManager.InviteFriends(message, title, new FacebookDelegate <IAppRequestResult>(this.OnFacebookInviteFriends)); }