/// <summary> Dispose by parent. </summary>
 public override void DisposeByParent()
 {
     if (_offBitmap != null && _offBitmapShared == false)
     {
         _offBitmap.Dispose();
         _offBitmap = null;
     }
     if (_onBitmap != null && _onBitmapShared == false)
     {
         _onBitmap.Dispose();
         _onBitmap = null;
     }
     base.DisposeByParent();
 }
 /// <summary> Dispose by parent. </summary>
 public override void DisposeByParent()
 {
     if (_leftBitmap != null && _leftBitmapShared == false)
     {
         _leftBitmap.Dispose();
         _leftBitmap = null;
     }
     if (_rightBitmap != null && _rightBitmapShared == false)
     {
         _rightBitmap.Dispose();
         _rightBitmap = null;
     }
     base.DisposeByParent();
 }