Мерцание при собственной отрисовке TreeView

private void TreeViewDrawNode(object sender, DrawTreeNodeEventArgs e)
{
    if (e.Node.Nodes.Count > 0)
    {
        var icon = e.Node.IsExpanded ? Res.Expanded : Res.Collapsed;
        var iconRect = new Rectangle(e.Bounds.X + e.Node.Level * 50, e.Bounds.Y + 5, icon.Width, icon.Height);
        e.Graphics.DrawIcon(icon, iconRect);
        var image = Images[e.Node.ImageIndex];
        var rect = new Rectangle(iconRect.Right, e.Bounds.Y, image.Width, image.Height);
        e.Graphics.DrawImage(image, rect);
        var point = new PointF(rect.Right + 5, rect.Top + 10);
        e.Graphics.DrawString(e.Node.Text, new Font("Georgia", 15), Brushes.DarkBlue, point);
    }
    else
    {
        var image = Images[e.Node.ImageIndex];
        var rect = new Rectangle(e.Bounds.X + e.Node.Level * 50 + 30, e.Bounds.Y, image.Width, image.Height);
        e.Graphics.DrawImage(image, rect);
        var point = new PointF(rect.Right + 5, rect.Top + 10);
        e.Graphics.DrawString(e.Node.Text, new Font("Georgia", 15), Brushes.Black, point);
    }
}