Flutter中Solana钱包交易失败问题求助

问题背景 #

使用solana_wallet_adapter调用Phantom、Solflare钱包进行SOL转账时遇到以下问题：

Phantom钱包问题 #

• 能正常显示连接授权弹窗和交易批准弹窗，但点击「批准」后无响应，一段时间后控制台报错：

  E/flutter (28131): [ERROR:flutter/runtime/dart_vm_initializer.cc(41)] Unhandled Exception: [JsonRpcException<dynamic>] -3 : sign request declined
  

Solflare钱包问题 #

• 能成功连接钱包，但滑动批准交易时提示「发生未知错误」，控制台反复出现：

  E/flutter (29334): [ERROR:flutter/runtime/dart_vm_initializer.cc(41)] Unhandled Exception: MissingPluginException(No implementation found for method callAsyncJavaScript on channel com.pichillilorenzo/flutter_inappwebview_...)
  

原代码 #

final adapter = SolanaWalletAdapter(
              const AppIdentity(),
              cluster: Cluster.devnet,
            );

            final Cluster cluster = Cluster.devnet;

            var blockHash = await web3.Connection(cluster).getLatestBlockhash();

            final connection = web3.Connection(
              cluster,
            );


            AuthorizeResult result = await adapter.authorize();


            final connectedAccount = adapter.connectedAccount?.address;
            if (connectedAccount == null) throw Exception('Connect wallet before sending tx.');

            // Mobile wallet displays the address as base-58.
            final rcv = web3.PublicKey.fromBase58("<some-address-here>");

            // Mobile wallet adapter specification returns address as base-64
            final snd = web3.PublicKey.fromBase64(connectedAccount);

            print('creating transaction');

            // Get latest blockhash info.
            final blockhash = await connection.getLatestBlockhash();

            // Create transfer tx.
            final transaction = web3.Transaction(
              feePayer: snd, // The account that will sign the tx (and pay any fees).
              recentBlockhash: blockhash.blockhash,
              lastValidBlockHeight: blockhash.lastValidBlockHeight,
              instructions: [
                SystemProgram.transfer(
                  fromPublicKey: snd,
                  toPublicKey: rcv,
                  lamports: web3.solToLamports(1),
                ),
              ],
            );

            // Serialize tx.
            const config = web3.SerializeConfig(requireAllSignatures: false);
            final tt = transaction.serialize(config).getString(web3.BufferEncoding.base64);
            print('creating transaction string $tt');

            // Sign and send tx.
            final txresult = await adapter.signAndSendTransactions(transactions: [tt]);

            // Wait for confirmation.
            await connection.confirmTransaction(base64ToBase58(txresult.signatures.first!));

解决方案 #

针对Phantom钱包的修复 #

1. 复用钱包适配器实例：不要每次点击按钮都新建SolanaWalletAdapter，重复创建会导致会话异常，建议将其作为类成员变量复用。
2. 优化Blockhash获取时机：提前获取的blockhash可能过期，必须在创建交易前才获取最新的blockhash，确保交易有效性。
3. 简化交易流程：移除冗余的blockHash变量，避免混淆。

针对Solflare钱包的修复 #

1. 集成flutter_inappwebview插件：Solflare内部依赖该插件的callAsyncJavaScript方法，需在项目中添加依赖：
   • 在pubspec.yaml中添加：

     dependencies:
       flutter_inappwebview: ^6.0.0 # 版本建议与solana_wallet_adapter依赖的版本匹配
     

   • 执行flutter pub get后重新运行项目。
2. 配置平台权限：
   • Android：在AndroidManifest.xml中添加网络权限：

     <uses-permission android:name="android.permission.INTERNET" />
     

   • iOS：在Info.plist中添加App Transport Security例外（若需要）：

     <key>NSAppTransportSecurity</key>
     <dict>
       <key>NSAllowsArbitraryLoads</key>
       <true/>
     </dict>
     

3. 清理缓存重建项目：执行flutter clean后重新构建，避免缓存导致的插件未加载问题。

修正后的代码示例 #

// 作为类成员变量，复用适配器实例
final SolanaWalletAdapter _adapter = SolanaWalletAdapter(
  const AppIdentity(),
  cluster: Cluster.devnet,
);
final Cluster _cluster = Cluster.devnet;
late final web3.Connection _connection;

@override
void initState() {
  super.initState();
  _connection = web3.Connection(_cluster);
}

// 按钮点击触发的转账方法
Future<void> _sendSol() async {
  try {
    // 授权连接钱包
    await _adapter.authorize();

    final connectedAccount = _adapter.connectedAccount?.address;
    if (connectedAccount == null) throw Exception('请先连接钱包');

    // 解析收款和付款地址
    final receiver = web3.PublicKey.fromBase58("<some-address-here>");
    final sender = web3.PublicKey.fromBase64(connectedAccount);

    // 创建交易前获取最新Blockhash
    final blockhashInfo = await _connection.getLatestBlockhash();

    // 构建转账交易
    final transaction = web3.Transaction(
      feePayer: sender,
      recentBlockhash: blockhashInfo.blockhash,
      lastValidBlockHeight: blockhashInfo.lastValidBlockHeight,
      instructions: [
        SystemProgram.transfer(
          fromPublicKey: sender,
          toPublicKey: receiver,
          lamports: web3.solToLamports(1),
        ),
      ],
    );

    // 序列化交易
    const serializeConfig = web3.SerializeConfig(requireAllSignatures: false);
    final serializedTx = transaction.serialize(serializeConfig).getString(web3.BufferEncoding.base64);

    // 签名并发送交易
    final txResult = await _adapter.signAndSendTransactions(transactions: [serializedTx]);

    // 确认交易
    if (txResult.signatures.isNotEmpty) {
      await _connection.confirmTransaction(txResult.signatures.first);
    }
  } catch (e) {
    print('转账失败：$e');
  }
}

内容的提问来源于stack exchange，提问作者Wilfred Almeida