BasicTransaction

Program.cs

class Program
{
	private static readonly Network _network = Network.TestNet;
	private static readonly BitcoinExtKey _seed = new BitcoinExtKey("tprv8ZgxMBicQKsPeGSjHbcTdpBxmVvRmySiUkQFBLruRTrn2dXAtn2rqApjVUgqsFkhfJZLYy8kXgRaEgZh7M3zdxyabF1TcwoxZsgpmAnHYyH");
	private static readonly ExtKey _fundingExtKey = _seed.ExtKey.Derive(0, false);
	private static readonly BitcoinAddress _fundingAddress = _fundingExtKey.ScriptPubKey.GetDestinationAddress(_network); // mkvRuHAv3qek4mP3ipjqFnaFXj4d2kKit3
	private static readonly QBitNinjaClient _qBitClient = new QBitNinjaClient(_network);
		
	static void Main(string[] args)
    {
		SpendBasicTransaction();
		ReadKey();
    }

	private static void SpendBasicTransaction()
	{
		uint256 txIdToSpend = _qBitClient.GetBalance(_fundingAddress, unspentOnly: false).Result.Operations.First().TransactionId; // f1e0865d087e3aeee1124e07c32b5cd7dda342c3d8dc691e54b9094f1f939df8
		Transaction txToSpend = _qBitClient.GetTransaction(txIdToSpend).Result.Transaction;

		Money fee = new Money(0.001m, MoneyUnit.BTC);
		var builder = new TransactionBuilder();
		var txThatSpends = builder
			.AddCoins(txToSpend)
			.AddKeys(_fundingExtKey)
			.SendFees(fee)
			.Send(_fundingAddress, txToSpend.Outputs.First().Value - fee)
			.BuildTransaction(true);

		var errors = builder.Check(txThatSpends);
		if (errors.Count() != 0)
		{
			WriteLine("Check failed. Errors:");
			foreach (var err in errors)
			{
				WriteLine(err);
			}
		}
		else
		{
			WriteLine(txThatSpends);
		}
	}
}