Прозрачный фон в DataGridView

 public class MyDataGridView : DataGridView
    {
        private Image backGroundImage;
        [Browsable(true)]
        public override Image BackgroundImage
        {
            get
            {
                return backGroundImage;
            }
            set
            {
                backGroundImage = value;
            }
        }
        protected override void PaintBackground(Graphics graphics, Rectangle clipBounds, Rectangle gridBounds)
        {
            if (BackgroundColor != null)
                graphics.DrawImageUnscaled(BackgroundImage, gridBounds);
            else
                base.PaintBackground(graphics, clipBounds, gridBounds);
        }
    }

MyDataGridView dgv = new MyDataGridView();
            this.Controls.Add(dgv);
            dgv.Show();
            dgv.BackgroundImage = null;

        protected override void PaintBackground(Graphics graphics, Rectangle clipBounds, Rectangle gridBounds)
        {
            if (BackgroundColor == null && backGroundImage != null)
            {
                graphics.DrawImageUnscaled(BackgroundImage, gridBounds);
            }
        }

  this.dataGridView1.BackgroundColor = Color.AliceBlue;