在发送交易之前如何获得估计的gas？

Question

您如何从“swapExactETHForTokens”函数中获得“估计气体”？如图metamask（之前可以接受购买）

币安智能链 (BSC)

从功能号 10 中的 pancakeswap 合约 (https://bscscan.com/address/0x10ed43c718714eb63d5aa57b78b54704e256024e#writeContract)，您可以使用“swapExactETHForTokens”购买代币，在功能号 14 中，您可以使用“swapExactTokens”出售代币

当您在想要买入或卖出时尝试进行交易并且无法继续进行时，则显示gas费用支出为“0.3”或“0.4”，这表明存在错误（并且显然不必接受）

在此示例中，这是因为我尝试在代币中没有定义价格/BNB 中没有流动性时购买代币，因此显示 0.3 bnb 的汽油费（错误）

我通过 BOT 自动“购买”和“出售”，它使用上述功能帮助我执行这些过程。如何获得“估计气体”的这个值，如“Metamask”中的示例所示？但使用 web3 或 ethers！

我在 ethers 中尝试了“estimateGas”，但它返回了一个正常的气体值，与元掩码为 0.3 bnb 的示例不同

    let test = async () => {
const provider_ = new ethers.providers.WebSocketProvider(data.Wss_Nodo); //Nodo Private
let tokenAbi_ = [{"inputs":[{"internalType":"string","name":"_name","type":"string"},{"internalType":"string","name":"_symbol","type":"string"},{"internalType":"uint256","name":"_decimals","type":"uint256"},{"internalType":"uint256","name":"_supply","type":"uint256"},{"internalType":"uint256","name":"_txFee","type":"uint256"},{"internalType":"uint256","name":"_burnFee","type":"uint256"},{"internalType":"uint256","name":"_charityFee","type":"uint256"},{"internalType":"address","name":"_FeeAddress","type":"address"},{"internalType":"address","name":"tokenOwner","type":"address"}],"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"owner","type":"address"},{"indexed":true,"internalType":"address","name":"spender","type":"address"},{"indexed":false,"internalType":"uint256","name":"value","type":"uint256"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"previousOwner","type":"address"},{"indexed":true,"internalType":"address","name":"newOwner","type":"address"}],"name":"OwnershipTransferred","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"from","type":"address"},{"indexed":true,"internalType":"address","name":"to","type":"address"},{"indexed":false,"internalType":"uint256","name":"value","type":"uint256"}],"name":"Transfer","type":"event"},{"inputs":[],"name":"FeeAddress","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"_BURN_FEE","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"_CHARITY_FEE","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"_TAX_FEE","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"_owner","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"owner","type":"address"},{"internalType":"address","name":"spender","type":"address"}],"name":"allowance","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"approve","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"account","type":"address"}],"name":"balanceOf","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"uint256","name":"_value","type":"uint256"}],"name":"burn","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"decimals","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"subtractedValue","type":"uint256"}],"name":"decreaseAllowance","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"uint256","name":"tAmount","type":"uint256"}],"name":"deliver","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"account","type":"address"}],"name":"excludeAccount","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"account","type":"address"}],"name":"includeAccount","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"addedValue","type":"uint256"}],"name":"increaseAllowance","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"account","type":"address"}],"name":"isCharity","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"account","type":"address"}],"name":"isExcluded","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"account","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"mint","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"name","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"owner","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"uint256","name":"tAmount","type":"uint256"},{"internalType":"bool","name":"deductTransferFee","type":"bool"}],"name":"reflectionFromToken","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"renounceOwnership","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"account","type":"address"}],"name":"setAsCharityAccount","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"symbol","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"uint256","name":"rAmount","type":"uint256"}],"name":"tokenFromReflection","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"totalBurn","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"totalCharity","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"totalFees","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"totalSupply","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"transfer","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"sender","type":"address"},{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"transferFrom","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"newOwner","type":"address"}],"name":"transferOwnership","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"uint256","name":"_txFee","type":"uint256"},{"internalType":"uint256","name":"_burnFee","type":"uint256"},{"internalType":"uint256","name":"_charityFee","type":"uint256"}],"name":"updateFee","outputs":[],"stateMutability":"nonpayable","type":"function"}];
const address_ = "0x3A7bf1305D0561b4E0363E6a262096c77C7CB5Db"; //My Wallet Test
const erc20 = new ethers.Contract(address_, tokenAbi_, provider_);

const recipient = "0x36953b5ec00a13edceceb3af258d034913d2a79d"; //Token Test
const estimation = await erc20.estimateGas.transfer(recipient, 100);
console.log(estimation) // BigNumber { _hex: '0x5444', _isBigNumber: true } (21572)
}

显然我做错了:(请帮忙！！

Answer 1

我正在使用 web3 来估计气体，它仅在我将代币从钱包转移到另一个钱包时才有效，但是在铸币时测试它时出现错误：

let estimated_gas = await web3.eth.estimateGas({
        'from': WalletAddress,
        'to': ContractAddress,
        'value': web3.utils.toHex(web3.utils.toWei('0.0035', 'ether')),
        'data': contract.methods.mint.encodeABI(),
        "gasPrice": web3.utils.toHex(gas_fee),
    });

我得到这个错误：

Error: Returned error: execution reverted: Value below required mint fee for the amount

不知道我做错了什么