通过 Kotlin SDK 获取数据

Kaptos 提供了覆盖 fullnode REST 端点、索引器端点以及 Move view 函数的数据读取 API。

基于 Result 的处理

网络调用返回 Result<Ok, Err>，你可以选择显式分支处理，或者使用 fail-fast 解包。

val ledgerInfoResult = aptos.getLedgerInfo()

when (ledgerInfoResult) {
  is Result.Ok -> println("Ledger version: ${ledgerInfoResult.value.ledgerVersion}")
  is Result.Err -> println("Failed to read ledger info: ${ledgerInfoResult.error.message}")
}

如果你更偏好 fail-fast：

val ledgerInfo = aptos.getLedgerInfo().expect("Failed to fetch ledger info")

更多处理模式，请参见 处理 SDK 数据读取响应。

读取链通用数据

val chainId = aptos.getChainId().expect("Failed to fetch chain id")
val latestBlock = aptos.getBlockByHeight(ledgerHeight = 1, withTransactions = true).expect("Failed to fetch block info")

读取账户数据

val address = AccountAddress.fromString("0x1")

val accountInfo = aptos.getAccountInfo(accountAddress = address).expect("Failed to fetch account info")
val modules = aptos.getAccountModules(accountAddress = address) { limit = 20 }.expect("Failed to fetch modules")
val resources = aptos.getAccountResources(accountAddress = address) { limit = 50 }.expect("Failed to fetch resources")

读取余额

通过索引器读取 APT 余额：

val aptBalance = aptos.getAccountAPTAmount(accountAddress = address).expect("Failed to fetch APT balance")

通过智能合约 view 路径读取指定 coin type：

val aptBalanceFromView =
  aptos
    .getAccountCoinAmountFromSmartContract(
      accountAddress = address,
      coinType = MoveValue.MoveStructId("0x1::aptos_coin::AptosCoin"),
    )
    .expect("Failed to fetch coin balance from smart contract")

通过 Move view 函数读取

使用 view<T>() 发起自定义只读 Move 调用。

val payload =
  InputViewFunctionData(
    function = "0x1::chain_id::get",
    typeArguments = emptyList(),
    functionArguments = emptyList(),
  )

val viewResult =
  aptos
    .view<List<MoveValue.MoveUint8Type>>(payload)
    .expect("Failed to execute view")

val chainIdFromView = viewResult.first().value