如何使用智能合约获得正确的余额？

Question

我有简单的智能合约：

pragma solidity ^0.7.0;

contract Token {
    string public name = "My Hardhat Token";
    string public symbol = "MHT";
    uint256 public totalSupply = 1000000;
    address public owner;
    mapping(address => uint256) balances;

    constructor() {
        balances[msg.sender] = totalSupply;
        owner = msg.sender;
    }

    function transfer(address to, uint256 amount) external {
        require(balances[msg.sender] >= amount, "Not enough tokens");
        balances[msg.sender] -= amount;
        balances[to] += amount;
    }

    function balanceOf(address account) external view returns (uint256) {
        return balances[account];
    }
}

我接受这份合同from

我已经成功编译并上传了这个智能合约到 ropsten 测试网。我使用安全帽框架来执行此操作。 https://hardhat.org/tutorial/deploying-to-a-live-network.html

之后，我编写了一个脚本来接收余额、执行转账并创建交易。

var provider = "https://eth-ropsten.alchemyapi.io/v2/iwxxx";
var Web3 = require('web3');
var web3 = new Web3(new Web3.providers.HttpProvider(provider));
const abi = [{...}];
const address = "0xC1xxx";    // after deploy smart contract
const senderAddress  = "0x2bxxx";
const receiverAddress  = "0x39xxx";
const privKey = "0xf5xxx";

const token = new web3.eth.Contract(abi, address);
token.setProvider(web3.currentProvider)
token.methods.balanceOf(address).call( (err, res) => { console.log("Address Balance: ", res); }); // 0
token.methods.balanceOf(senderAddress).call((err, res) => { console.log("SenderAddress Balance: ", res); }); // 0

token.methods.transfer(receiverAddress, "1").send({ "from": address }, (err, res) => {
    if (err) {console.log("Error occured ! ", err);return}
    console.log("Hash transaction: " + res);
});

send_tr();
async function send_tr(){
    let transactionNonce = await web3.eth.getTransactionCount(senderAddress);
    let raw = {"to":receiverAddress, "value":"1", "gas":2000000, "nonce":web3.utils.toHex(transactionNonce)};
    const signedTx = await web3.eth.accounts.signTransaction(raw, privKey);
    await web3.eth.sendSignedTransaction(signedTx.rawTransaction, (err, ret) => {
        if (err) {console.log("An error occurred", err);return;}
        console.log("Success, txHash is: ", ret);
    });
}

问题是为什么我的余额为零，即使合约部署不足？

最后交易成功（据我了解，需要交易才能使从地址转移到地址的代币转移成功）

Answer 1

在solidity 构造函数中，您设置的是部署者地址的余额，而不是合约地址的余额。

constructor() {
    balances[msg.sender] = totalSupply;
    owner = msg.sender;
}

但是在 JS 脚本中，你是在询问合约地址的余额。

const token = new web3.eth.Contract(abi, address);
token.methods.balanceOf(address)