Code

private DiagramLink currentLink = null;

private void diagram_NodeClicked(object sender, NodeEventArgs e)
{
	if (currentLink == null)
	{
		currentLink = diagram.Factory.CreateDiagramLink(e.Node, e.MousePosition);
	}
	else
	{
		currentLink.Destination = e.Node;
		currentLink = null;
	}
}

private void diagramView_MouseMove(object sender, MouseEventArgs e)
{
	if (currentLink != null)
	{
		PointF mousePos = diagramView.ClientToDoc(e.Location);
		currentLink.ControlPoints[currentLink.ControlPoints.Count - 1] = mousePos;
		currentLink.UpdateFromPoints();
	}
}