bitcoinspend.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using NBitcoin;
using QBitNinja.Client;
using QBitNinja.Client.Models;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            // generated WIF earlier; use that now to get private key
            var bitcoinPrivateKey = new
BitcoinSecret("BITCOIN SECRET HERE");

            // network will be on testnet
            var network = bitcoinPrivateKey.Network;
            var address = bitcoinPrivateKey.GetAddress();

            Console.WriteLine(bitcoinPrivateKey);
            Console.WriteLine(address);

            // tx id from faucet: 42324295bb74b2e10831a6d3e090f8c7bb4c60fe2fff36ec39c3d72cdbf0e3e2
            var client = new QBitNinjaClient(network);
            var transactionId = uint256.Parse("42324295bb74b2e10831a6d3e090f8c7bb4c60fe2fff36ec39c3d72cdbf0e3e2");
            var transactionResponse = client.GetTransaction(transactionId).Result;

            Console.WriteLine(transactionResponse.TransactionId);
            Console.WriteLine(transactionResponse.Block.Confirmations);

            var receivedCoins = transactionResponse.ReceivedCoins;
            OutPoint outPointToSpend = null;
            foreach (var coin in receivedCoins)
            {
                if (coin.TxOut.ScriptPubKey == bitcoinPrivateKey.ScriptPubKey)
                {
                    outPointToSpend = coin.Outpoint;
                }

            }
            if (outPointToSpend == null)
                throw new Exception("TxOut does not contain our ScriptPubKey");

            Console.WriteLine("We want to spend {0} outpoint", outPointToSpend.N +1);

            var transaction = new Transaction();
            transaction.Inputs.Add(new TxIn()
            {
                PrevOut = outPointToSpend
            });

            // address to spend to; use this for testnet address
            var copayWallet = BitcoinAddress.Create("myTV1ojgfFt7WUXKxkaz6eoLPJ1Cg9grP7");

            // txout to copay wallet address
            TxOut copayTxOut = new TxOut()
            {
                Value = new Money((decimal)0.5, MoneyUnit.BTC),
                ScriptPubKey = copayWallet.ScriptPubKey
            };

            // txout of remainder to yourself minus miner fee
            TxOut changeTxOut = new TxOut()
            {
                Value = new Money((decimal)0.59, MoneyUnit.BTC),
                ScriptPubKey = bitcoinPrivateKey.ScriptPubKey
            };

            transaction.Outputs.Add(copayTxOut);
            transaction.Outputs.Add(changeTxOut);

            var message = "NBitcoin rocks!";
            var bytes = Encoding.UTF8.GetBytes(message);
            transaction.Outputs.Add(new TxOut()
            {
                Value = Money.Zero,
                ScriptPubKey = TxNullDataTemplate.Instance.GenerateScriptPubKey(bytes)
            });

            transaction.Inputs[0].ScriptSig = bitcoinPrivateKey.ScriptPubKey;
            transaction.Sign(bitcoinPrivateKey, false);

            // now we have to propagate the tx
            // I do not have own Bitcoin Core so use QBitNinja
            BroadcastResponse broadcastResponse = client.Broadcast(transaction).Result;

            if (!broadcastResponse.Success)
            {
                Console.WriteLine("ErrorCode: " + broadcastResponse.Error.ErrorCode);
                Console.WriteLine("Error message: " + broadcastResponse.Error.Reason);
            }
            else
            {
                Console.WriteLine("Success! You can check out the hash of the transaciton in any block explorer:");
                Console.WriteLine(transaction.GetHash());
            }


            Console.ReadKey();
        }
    }
}