Mouse interact doesn't work with HitTest

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace OxyPlot.Extended.Annotations {
    public class RectangleAnnotationMovable2:RectangleAnnotation {
        private DataPoint lastPoint = DataPoint.Undefined;
        private OxyRect screenRectangle;
        private int handleNumber;
        private OxyColor originalStroke;
        private double originalStrokeThickness;
        private OxyColor originalFill;

        protected override void OnMouseDown(object sender, OxyMouseEventArgs e) {
            if ( this.PlotModel == null)
                return;
            handleNumber = (int)e.HitTestResult.Index;
            lastPoint = this.InverseTransform(e.Position);
            originalFill = this.Fill;

            this.Fill = OxyColors.Red;
            this.PlotModel.InvalidatePlot(false);
            e.Handled = true;
        }

        protected override void OnMouseMove(object sender, OxyMouseEventArgs e) {
            if (this.PlotModel == null)
                return;
            var thisPoint = this.InverseTransform(e.Position);
            double dx = thisPoint.X - lastPoint.X;
            double dy = thisPoint.Y - lastPoint.Y;
            switch (handleNumber) {
                case 1:
                    this.MinimumX += dx;
                    this.MaximumY += dy;
                    break;
                case 2:
                    this.MaximumY += dy;
                    break;
                case 3:
                    this.MaximumX += dx;
                    this.MaximumY += dy;
                    break;
                case 4:
                    this.MaximumY += dy;
                    break;
                case 5:
                    this.MaximumX += dx;
                    this.MinimumY += dy;
                    break;
                case 6:
                    this.MinimumY += dy;
                    break;
                case 7:
                    this.MinimumX += dx;
                    this.MinimumY += dy;
                    break;
                case 8:
                    this.MinimumX += dx;
                    break;
            }
            lastPoint = thisPoint;
            this.PlotModel.InvalidatePlot(false);
            e.Handled = true;
        }
        protected override void OnMouseUp(object sender, OxyMouseEventArgs e) {
            if (this.PlotModel == null)
                return;
            this.Fill = originalFill;

        }
        /// <summary>
        /// Tests if the plot element is hit by the specified point.
        /// </summary>
        /// <param name="point">
        /// The point. 
        /// </param>
        /// <param name="tolerance">
        /// The tolerance. 
        /// </param>
        /// <returns>
        /// A hit test result. 
        /// </returns>
        protected  override HitTestResult HitTest(ScreenPoint point, double tolerance) {
            if (screenRectangle.Contains(point)) {
                return new HitTestResult(point);
            }

            return null;
        }

      
    }
}