private void pictureBoxPicture_MouseMove(object sender, MouseEventArgs e) { if (!moving) { return; } int difX = pictureBoxPicture.PointToClient(Cursor.Position).X - startingPosition.X; int difY = pictureBoxPicture.PointToClient(Cursor.Position).Y - startingPosition.Y; brush.Move(difX, difY); startingPosition = new Point(e.X, e.Y); pictureBoxPicture.Refresh(); }