private void SetPictureVisible(ref PictureBox pic, Boolean isVisible) { if (!pic.InvokeRequired) { pic.Visible = isVisible; } else { PictureBox picControl = pic; SetPictureVisibleDelegate setPictureBoxVisibleDelegate = new SetPictureVisibleDelegate(SetPictureVisible); Object[] objArray = new Object[] { pic, isVisible }; picControl.Invoke(setPictureBoxVisibleDelegate, objArray); } }