Code

diagramView.Behavior = Behavior.DrawLinks;
diagram.AllowUnconnectedLinks = true;
diagram.RouteLinks = true;
diagram.LinkShape = LinkShape.Cascading;
diagram.LinkSegments = 3;
diagram.LinkRouter = new MyRouter(diagram);

class MyRouter : ILinkRouter
{
	public MyRouter(Diagram diagram)
	{
		qr = new QuickRouter(diagram);
	}

	QuickRouter qr;

	public bool RouteLink(DiagramLink link)
	{
		if (link.IsConnected || Diagram.Nodes.Any(link.Intersects))
			return qr.RouteLink(link);
		return true;
	}

	public void RouteLinks(DiagramLinkCollection links)
	{
		var newList = new DiagramLinkCollection();
		foreach (var link in links)
			if (link.IsConnected || Diagram.Nodes.Any(link.Intersects))
				newList.Add(link);
		qr.RouteLinks(newList);
	}

	public void Suspend()
	{
		qr.Suspend();
	}

	public void Resume(bool routeDeferredLinks)
	{
		qr.Resume(routeDeferredLinks);
	}

	public Diagram Diagram
	{
		get { return qr.Diagram; }
		set { qr.Diagram = value; }
	}
}