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批准需要时间确认吗?在BSC中如何处理?

erc20 web3js ethereum

Ron · 技术社区 · 5 年前

大家好,我正在使用web3和react进行BSC DApp。我对这个领域很陌生。

打电话后我发现 approve 这个 transfer (或者在我的例子中是zapInToken)抱怨没有足够的津贴是不会成功的。于是我又加了一句 wait allowance 出现10秒,但在很多情况下(50%的几率)10秒后,津贴仍然不存在。请查看下面的代码以了解更多信息。

理论上, 批准 将生成一个事务,出现的时间取决于。如果是这样的话,这是一种标准模式吗 批准 , wait for allowance 和 ?

非常感谢。

const bepContract = getContract(getAddress(from), erc20ABI, library, account)
const tx = await bepContract.approve(getAddress(contracts.zap), weiAmount)
if (!tx) {
    throw new Error('Failed to approve transaction')
}
await waitAllowance(bepContract, account, getAddress(contracts.zap), weiAmount, 10) // <-- and it will stuck here in most time, the code waits for the allowance is present
await getZapContract().zapInToken(getAddress(from), weiAmount, getAddress(to)).then(logInfo).catch(logError)

比如说低于零用钱

const waitAllowance = async (
  contract: Contract,
  account: string,
  to: string,
  allowanceNeeded: string,
  timesLeft: number
): Promise<void> => {
  if (timesLeft > 1) {
    const currentAllowance = await contract.allowance(account, to)
    // console.log(`I want ${allowanceNeeded}, and current is ${currentAllowance} `)
    const needed = new BigNumber(allowanceNeeded)
    const current = new BigNumber(currentAllowance.toString())
    if (current.isGreaterThanOrEqualTo(needed)) {
      return
    }
    await new Promise((res) => setTimeout(res, 1000))
    await waitAllowance(contract, account, to, allowanceNeeded, timesLeft - 1)
  }
  throw new Error('wait allowance failed for many times.')
}

0 回复 | 直到 5 年前

Ron 5 年前

我明白了,我需要 tx.wait ,因此工作代码如下所示:

const bepContract = getContract(getAddress(from), erc20ABI, library, account)
const tx = await bepContract.approve(getAddress(contracts.zap), weiAmount)
if (!tx) {
    throw new Error('Failed to approve transaction')
}
const tx = await waitAllowance(bepContract, account, getAddress(contracts.zap), weiAmount, 10)
const txResult = await tx.wait()
if (txResult.status !== 1) {
    throw new Error('Failed approve')
}
const txZap = await getZapContract().zapInToken(getAddress(from), weiAmount, getAddress(to))
const txZapResult = await txZap.wait()
if (txZapResult.status !== 1) {
    throw new Error('Failed zap')
}

看看这个 doc 从更多细节

Nagibaba 4 年前

经过数小时的调试,我意识到这是由于我使用的节点。从 getblock 到 Moralis 而且成功了