Setup Behavior event of its dependency property and connect to the instance not static

Dependency Prop inside a behavior is static. So its event fires into a static event handler.
But the dependencyObject in the param is the hehavior instance and can call instance method.

       public static readonly DependencyProperty TradingLevelProperty = DependencyProperty.Register(
        "TradingLevel", typeof(TradingLevelTypes), typeof(NumericTextBoxCustomParamBehavior), new PropertyMetadata(TradingLevelTypes.Low, TradingLevelrPropertyChanged));

        public TradingLevelTypes TradingLevel
        {
            get { return (TradingLevelTypes)GetValue(TradingLevelProperty); }
            set { SetValue(TradingLevelProperty, value); }
        }



        private static void TradingLevelrPropertyChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs dependencyPropertyChangedEventArgs)
        {
            var behaviorInstance = dependencyObject as NumericTextBoxCustomParamBehavior;
            if (behaviorInstance != null)
            {
                behaviorInstance.EnsureNonNullableDataVisibility();
            }
        }

        void EnsureNonNullableDataVisibility()
        {
            var scrollContentPresenter = AssociatedObject.FindChild("PART_ScrollContentPresenter");
            if (scrollContentPresenter != null)
            {
                scrollContentPresenter.Visibility=TradingLevel== TradingLevelTypes.ServerDefault? Visibility.Hidden: Visibility.Visible;
            }
        }