protected override void OnMouseDown(MouseEventArgs e) { base.OnMouseDown(e); if (_hoverDepthLine != null) { var edl = new EditDepthLine(_hoverDepthLine); edl.ShowDialog(this); SaveTripWires(); return; } int startX = e.X; int startY = e.Y; _pointStart = new Point(startX, startY); _pointEnd = new Point(startX, startY); OnBoundsChanged(); _bMouseDown = true; }