XeroAPI

// Try and create an invoice - but using incorrect data. This should hopefully be rejected by the Xero API
Invoice invoiceToCreate = new Invoice
{
    Contact = contact,
    Type = "ACCREC",
    Date = DateTime.Today,
    LineItems = new LineItems
    {
        new LineItem
        {

XeroAPI

<Invoice>
  <Type>ACCREC</Type> 
  <Contact> 
    <ContactID>8fbad9ef-d451-447e-ba2b-5bccc10acd9f</ContactID> 
  </Contact> 
  <Date>2011-09-22</Date>
  ...
</Invoice>

XeroAPI

static void Main(string[] args)
{
    IOAuthSession session = new XeroApi.OAuth.XeroApiPrivateSession(
        "XeroAPI Mini App",
        "YOUR-CONSUMER-KEY",
        new X509Certificate2(@"D:\Your-Certificate.pfx", "your-pfx-password"));

    Repository repository = new Repository(session);

    Console.WriteLine("You're connected to " + repository.Organisation.Name);

XeroAPI

  <Invoices>
    <Invoice>
      <Contact>
        <ContactID>aacecb74-ef1e-44e0-ba52-0bc521639697</ContactID>
        <ContactNumber>C290348</ContactNumber>
        <Name>PC Complete</Name>
      </Contact>
      ...
    </Invoice>
  </Invoices>