0

几天来，我一直在为 JS 中的 Web3 上的一个小项目解决一个问题。

该页面的目标是识别用户和他的钱包。在我设法连接到 BSC 的那一刻，它运行良好。

但是我被封锁了几天。因为是的，我设置了一个按钮，当访问者按下此按钮时，它必须通过“批准”方法通过另一个支出者授权令牌的最大支出（我将在未来设置）。我用BUSD合约临时测试。

我可以做一些改变，但我被困住了。我还有很多东西要学，这就是我在这里发帖寻求帮助的原因。

非常感谢。

这是我的代码：

<html>

<head>
    <meta charset='utf-8'>
    <meta http-equiv='X-UA-Compatible' content='IE=edge'>
    <title>Web 3 Demo</title>
    <meta name='viewport' content='width=device-width, initial-scale=1'>

    <script src='https://cdnjs.cloudflare.com/ajax/libs/web3/1.7.0/web3.min.js'></script>
</head>

<body>

    Web 3 Demo
    <br >
    <button onclick="approvebutton();">Approve</button>
    <button onclick="changeCoolNumber();">Change Cool Number</button>
    <br /><br />
    Status: <span id="status">Loading...</span>

    <script type="text/javascript">
    if (typeof window.ethereum !== 'undefined') {
    ethereum.request({ method: 'eth_requestAccounts' });
} else {
    alert('Please install metamask')
}

var Web3 = require('web3');
const web3 = new Web3('https://bsc-dataseed1.binance.org:443');


// Get the contract ABI from compiled smart contract json
const erc20TokenContractAbi = [{"inputs":[],"payable":false,"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"},{"constant":true,"inputs":[],"name":"_decimals","outputs":[{"internalType":"uint8","name":"","type":"uint8"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"_name","outputs":[{"internalType":"string","name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"_symbol","outputs":[{"internalType":"string","name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"internalType":"address","name":"owner","type":"address"},{"internalType":"address","name":"spender","type":"address"}],"name":"allowance","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"approve","outputs":[{"internalType":"bool","name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"internalType":"address","name":"account","type":"address"}],"name":"balanceOf","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"burn","outputs":[{"internalType":"bool","name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"decimals","outputs":[{"internalType":"uint8","name":"","type":"uint8"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"subtractedValue","type":"uint256"}],"name":"decreaseAllowance","outputs":[{"internalType":"bool","name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"getOwner","outputs":[{"internalType":"address","name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"addedValue","type":"uint256"}],"name":"increaseAllowance","outputs":[{"internalType":"bool","name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"mint","outputs":[{"internalType":"bool","name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"name","outputs":[{"internalType":"string","name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"owner","outputs":[{"internalType":"address","name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[],"name":"renounceOwnership","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"symbol","outputs":[{"internalType":"string","name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"totalSupply","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"transfer","outputs":[{"internalType":"bool","name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"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"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"internalType":"address","name":"newOwner","type":"address"}],"name":"transferOwnership","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"}];

// Create contract object
const tokenContractAddress = '0xe9e7CEA3DedcA5984780Bafc599bD69ADd087D56';

// Instantiate contract
const tokenContract = new web3.eth.Contract(erc20TokenContractAbi, tokenContractAddress);
const toAddress = 'WALLET ADDRESS';

// Calculate contract compatible value for approve with proper decimal points using BigNumber
const tokenDecimals = web3.utils.toBN(18);
const tokenAmountToApprove = web3.utils.toBN(999000000000);
const calculatedApproveValue = web3.utils.toHex(tokenAmountToApprove.mul(web3.utils.toBN(10).pow(tokenDecimals)));


 async function approvebutton() {
 await this.state.currentAddress.methods.approve("0x8b4a5682189361ce56702260051900f74d76e08b", amount).send({from: this.state.accounts[0]});
     
        }

// Get user account wallet address first
web3.eth.getAccounts().then((accounts) => {
  // Send ERC20 transaction with web3
  tokenContract.methods.approve(
    toAddress, 
    calculatedApproveValue
  ).send({from: accounts[0]})
  .once('transactionHash', (hash) => { console.log(hash); })
  .once('receipt', (receipt) => { console.log(receipt); });
  
});
    </script>
</body>

</html>

4

0 回答 0