private void ClearEdgeBp()
        {
            if (edgeBlueprint == null)
            {
                return;
            }

            graphArea.RemoveCustomChildControl(edgeBlueprint.EdgePath);
            edgeBlueprint.Dispose();
            edgeBlueprint = null;
        }
 public void CreateVirtualEdge(VertexControl source, Point mousePos)
 {
     edgeBlueprint = new EdgeBlueprint(source, mousePos, (LinearGradientBrush) resourceDictionary["EdgeBrush"]);
     graphArea.InsertCustomChildControl(0, edgeBlueprint.EdgePath);
 }