line not appearing

Question

        UserControl? movingObject;
        Point offset;
        Line l = new Line();

        bool makingConnection;
        private void X_PreviewMouseLeftDown(object sender, MouseButtonEventArgs e)
        {
            if (Keyboard.IsKeyDown(Key.LeftCtrl))
            {
                movingObject = sender as UserControl;
                offset = e.GetPosition(canvas);
                offset.Y -= Canvas.GetTop(movingObject);
                offset.X -= Canvas.GetLeft(movingObject);
                canvas.CaptureMouse();
                Mouse.OverrideCursor = new Cursor(@"C:\Users\conra\source\repos\WpfApp1\WpfApp1\\grabbing.cur");
            }
            parentControl pc = (parentControl)sender;
            foreach(connector c in pc.connectors)
            {
                if (c.isClicked)
                {
                    makingConnection = true;
                    l.X1 = e.GetPosition(canvas).X;
                    l.Y1 = e.GetPosition(canvas).Y;
                }
            }
        }
        private void canvas_PreviewMouseMove(object sender, MouseEventArgs e)
        {
            if (movingObject == null) return;
            Point pp = e.GetPosition(sender as IInputElement);
            Canvas.SetTop(movingObject, pp.Y - offset.Y);
            Canvas.SetLeft(movingObject, pp.X - offset.X);

            if (makingConnection)
            {
                l.Stroke = Brushes.Black;
                l.StrokeThickness = 4;
                l.X2 = e.GetPosition(sender as IInputElement).X;
                l.Y2 = e.GetPosition(sender as IInputElement).Y;
                canvas.Children.Add(l);
            }
        }

im trying to get it so that when a button is clicked it make a line from the button position to the position of the mouse on mouse move, this just doesnt add a line and i dont know why