void _hideFullScreen()
        {
            if (_spinnerInstance != null)
            {
               _spinnerInstance.RemoveFromSuperview();
            }

            _spinnerInstance = null;
        }
        void _showFullScreen(string text)
        {
            if (_spinnerInstance != null)
            {
                _spinnerInstance.Text = text;
                return;
            }

            _spinnerInstance = new LoadingOverlayView(UIScreen.MainScreen.Bounds);

            _spinnerInstance.Text = text;

            XiOSRoot.RootWindow.AddSubview(_spinnerInstance);
        }