Creating a new invoice - xero-api

Question

I can see list of all invoices for organisations using the Xero OAuth 2 sample from Xero-NetStandard. I want to create a new invoice for a particular tenant/organisation, how do I create an invoice object and what should the POST Method look like? Below code is what I have so far :
public async Task<string> InvoicesPostAsync()
{
var token = await _tokenStore.GetAccessTokenAsync(User.XeroUserId());
var connections = await _xeroClient.GetConnectionsAsync(token);
List<string> allinvoicenames = new List<string>();
foreach (var connection in connections)
{
var tenantID = connection.TenantId.ToString();
var request = (HttpWebRequest)WebRequest.Create("https://api.xero.com/api.xro/2.0/Invoices");
var postData = "thing1=hello";
var data = Encoding.ASCII.GetBytes(postData);
request.Method = "POST";
request.Headers.Add("Authorization" , "Bearer "+ token);
request.Headers.Add("Xero-tenant-id" , tenantID);
request.ContentType = "application/x-www-form-urlencoded";
request.Credentials = CredentialCache.DefaultCredentials;
request.ContentLength = data.Length;
using (var stream = request.GetRequestStream())
{
stream.Write(data, 0, data.Length);
}
var response = (HttpWebResponse)request.GetResponse();
}

Answer 1

Out of curiosity, which OAuth2.0 sample are you referring to?
This sample app that I put together makes use of our new OAuth2.0 SDK - https://github.com/XeroAPI/xero-netstandard-oauth2-samples/tree/master/XeroOAuth2Sample
The same SDK can be used to create invoices. Below is a bit of sample code to do so
var invoice = new Invoice
{
Type = Invoice.TypeEnum.ACCREC,
Contact = new Contact
{
Name = "Some contact name"
},
Date = DateTime.Today,
DueDate = DateTime.Today.AddDays(7),
Status = Invoice.StatusEnum.DRAFT,
LineItems = new List<LineItem>
{
new LineItem
{
Description = "Manchester United Scarf",
Quantity = 1,
UnitAmount = 24.99,
AccountCode = "200"
}
}
};
var createdInvoice = await _accountingApi.CreateInvoiceAsync(accessToken, tenantId, invoice);