protected override void Render(HtmlTextWriter writer) { int id; bool hasid = int.TryParse(NodeId, out id); int? nodeId = hasid ? id : (int?)null; string url; bool imageFound = ImageUrl.TryGetImageUrl(Src, Field, Provider, Parameters, nodeId, out url); Src = url; if (imageFound) { base.Render(writer); } }