赞助交易

本节介绍如何使用 Aptos .NET SDK 执行赞助交易。

请务必先了解构建交易的基础知识。如不了解，请参阅以下指南。

基础交易了解如何使用 Aptos .NET SDK 构建基础交易。

创建赞助交易

配置 AptosClient

通过添加 Aptos 命名空间并实例化 AptosClient 来配置 Aptos 客户端。你可以使用 Networks 提供的预定义配置，也可以自行配置。

using Aptos;

class Program
{
    static void Main(string[] args)
    {
        var config = new AptosConfig(Aptos.Networks.Mainnet);
        var client = new AptosClient(config);
    }
}

配置账户

创建赞助交易时，必须有赞助者和用户。在本例中：

**用户：**向接收者发送 APT 的账户。
赞助者：支付交易Gas 费用的账户。

using Aptos;

class Program
{
    static void Main(string[] args)
    {
        var config = new AptosConfig(Aptos.Networks.Devnet);
        var client = new AptosClient(config);

        // 1. Create accounts and fund it them.
        var user = Account.Generate();
        var recipient = Account.Generate();
        var sponsor = Account.Generate();

        await client.Faucet.FundAccount(user.Address, 100_000_000);
        await client.Faucet.FundAccount(sponsor.Address, 100_000_000);
    }
}

构建交易

现在可以使用 AptosClient 构建交易。必须在交易中启用 withFeePayer 标志，才能启用赞助交易。

using Aptos;

class Program
{
    static void Main(string[] args)
    {
        ...

        // 2. Build the transaction
        var transaction = await client.Transaction.Build(
            sender: account,
            data: new GenerateEntryFunctionPayloadData(
                function: "0x1::aptos_account::transfer_coins",
                typeArguments: ["0x1::aptos_coin::AptosCoin"],
                functionArguments: [account.Address, "100000"]
            ),
            // It's important to set this flag to true to enable sponsored transactions
            withFeePayer: true
        );
    }
}

使用两个账户签名交易

让用户和赞助者都签署交易。这可确保赞助者同意支付交易费用，用户同意执行交易。使用赞助者签名时，应改用 SignAsFeePayer 方法。

using Aptos;

class Program
{
    static void Main(string[] args)
    {
        ...

        // 3. Sign the transaction with the user
        var userSignature = client.Transaction.SignTransaction(transaction);

        // 4. Sign the transaction with the sponsor
        var feePayerSignature = client.Transaction.SignAsFeePayer(feePayer, transaction);
    }
}

提交交易

用户和赞助者都签名后，即可将交易提交到区块链。AptosClient 可用于提交交易。

using Aptos;

class Program
{
    static void Main(string[] args)
    {
        ...

        // 5. Submit the transaction
        var submitTransactionData = new SubmitTransactionData(transaction, userSignature, feePayerSignature);
        var submittedTransaction = await client.Transaction.SubmitTransaction(submitTransactionData);
    }
}

等待交易执行

交易提交后，需要先完成处理，才能提交到区块链。AptosClient 可用于等待交易被处理和执行。

using Aptos;

class Program
{
    static void Main(string[] args)
    {
        ...

        // 6. Wait for the transaction to be processed
        var transactionResult = await client.Transaction.WaitForTransaction(submittedTransaction.Hash);
    }
}

打印余额

交易提交到区块链后，可打印用户和接收者的余额。

using Aptos;

class Program
{
    static void Main(string[] args)
    {
        ...

        // 7. Print balances
        var userBalance = await client.Account.GetCoinBalance(user.Address);
        var feePayerBalance = await client.Account.GetCoinBalance(feePayer.Address);
        var recipientBalance = await client.Account.GetCoinBalance(recipient.Address);
        Console.WriteLine($"User {user.Address} has {userBalance?.Amount ?? 0} APT");
        Console.WriteLine($"FeePayer {feePayer.Address} has {feePayerBalance?.Amount ?? 0} APT");
        Console.WriteLine($"Recipient {recipient.Address} has {recipientBalance?.Amount ?? 0} APT");
    }
}

结果应如下所示：

User 0xffd89f1e2fef8c67cfb1b99d58ea799281f1d1a0a178db49c3eacab2fe7c0735 has 99900000 APT
FeePayer 0x842ca7d995255ee73186a6793d6bde7c983c528be7b1a25e1614f4eddb744d4c has 99900100 APT
Recipient 0x823010a52a589ef528d14ebee4a4af56a00f0ae8afba135c9268581a960e21d7 has 100000 APT

用户向接收者发送了 0.001 APT，因此用户剩余 0.999 APT。赞助者支付了交易的 Gas 费用，因此赞助者剩余 0.999001 APT。