StructureHelper/StructureHelper/Infrastructure/MouseBehaviour.cs

using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Interactivity;

namespace StructureHelper.Infrastructure
{
    public class MouseBehaviour : Behavior<Panel>
    {
        public static readonly DependencyProperty MouseYProperty = DependencyProperty.Register(
            "MouseY", typeof(double), typeof(MouseBehaviour), new PropertyMetadata(default(double)));

        public static readonly DependencyProperty MouseXProperty = DependencyProperty.Register(
            "MouseX", typeof(double), typeof(MouseBehaviour), new PropertyMetadata(default(double)));

        public double MouseY
        {
            get => (double)GetValue(MouseYProperty);
            set => SetValue(MouseYProperty, value);
        }

        public double MouseX
        {
            get => (double)GetValue(MouseXProperty);
            set => SetValue(MouseXProperty, value);
        }

        protected override void OnAttached()
        {
            AssociatedObject.MouseMove += AssociatedObjectOnMouseMove;
        }

        protected override void OnDetaching()
        {
            AssociatedObject.MouseMove -= AssociatedObjectOnMouseMove;
        }

        private void AssociatedObjectOnMouseMove(object sender, MouseEventArgs mouseEventArgs)
        {
            var pos = mouseEventArgs.GetPosition(AssociatedObject);
            MouseX = pos.X;
            MouseY = pos.Y;
        }
    }
}