private void OnBindingContextChanged(object sender, EventArgs e)
 {
     if (_control.BindingContext is StreemaControlViewModel model)
     {
         _viewModel = model;
     }
 }
        protected override void OnAttachedTo(Slider control)
        {
            _control   = control;
            _viewModel = control.BindingContext as StreemaControlViewModel;

            control.BindingContextChanged += OnBindingContextChanged;
            control.ValueChanged          += OnValueChanged;

            base.OnAttachedTo(control);
        }