protected override void OnPaint(PaintEventArgs e)
 {
     e.Graphics.SmoothingMode     = SmoothingMode.AntiAlias;
     e.Graphics.TextRenderingHint = System.Drawing.Text.TextRenderingHint.AntiAlias;
     base.OnPaint(e);
     if (_geometryGraph == null)
     {
         _geometryGraph = CreateAndLayoutGraph();
     }
     DrawingUtilsForSamples.DrawFromGraph(ClientRectangle, _geometryGraph, e.Graphics);
 }
        private void Graph_Drawn(object sender, DrawnArgs args)
        {
            var context = args.Cr;

            DrawingUtilsForSamples.DrawFromGraph(new Cairo.Rectangle(0, 0, width, height), graph, args.Cr);
        }