How to get Purchase Order with Orderlines using .Net SDK?

Dim Pur1Svc = New Purchase.ServicePurchaseOrderService(myConfiguration, Nothing, _oAuthKeyService)

Pur1Svc.GetRange(companyFile, null, credentials, OnServicePurchaseOrderLineComplete, OnError)

returns all service purchase orders as a paged list (usually 1000 at a time) with lines (if you do not use filters)

loopint = 0 to bills,items.count-1

...

If Bills.Items(loopint).Lines.Count > 0 Then

...

For lineitems = 0 To lvBills.Items(loopint).Lines.Count - 1

 ...   iterates through all PO line(s) in purchase order(s)