public ChatPage()
        {
            InitializeComponent();

            NavigationPage.SetTitleIcon(this, "*****@*****.**");

            MessagingCenter.Subscribe <DBFire, Room>(this, "RoomProp", (page, data) =>
            {
                rm = data;
                _listChat.BindingContext = dB.subChat(data.Key);
                MessagingCenter.Unsubscribe <DBFire, Room>(this, "RoomProp");
            });
        }
        public ChatPage()
        {
            InitializeComponent();

            MessagingCenter.Subscribe <RoomPage, Room>(this, "RoomProp", (page, data) =>
            {
                rm = data;

                _lstChat.BindingContext = db.subChat(data.Key);

                MessagingCenter.Unsubscribe <RoomPage, Room>(this, "RoomProp");
            });
        }