Web3.js查询以太币和代币余额以及转账

- 日理万妓 2022-10-07 05:51 178阅读 0赞

# 安装 #

npm install web3

> web3.js查询以太币及代币余额以及进行以太币和代币转账

## 在私链和主链上查询以太币及代币余额 ##

> 查询类方法在私链和主链上的方法都是一样的
> 
>  *  主链地址。可以去`infura`申请
>  *  `contractAbi`。合约的abi。可以去[https://etherscan.io][https_etherscan.io]获取，如果代币合约提供了`code`，就会有`abi`

// 引入web3
    var Web3 = require('web3');
    if (typeof web3 !== 'undefined') {
        web3 = new Web3(web3.currentProvider);
    } else {
        // web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:7545"));
        web3 = new Web3(new Web3.providers.HttpProvider("https://mainnet.infura.io/yourAddress"));
    }
     
    // 定义合约abi
    var contractAbi = [{"constant":true,"inputs":[],"name":"mintingFinished","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"name","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_spender","type":"address"},{"name":"_value","type":"uint256"}],"name":"approve","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"totalSupply","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_from","type":"address"},{"name":"_to","type":"address"},{"name":"_value","type":"uint256"}],"name":"transferFrom","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"decimals","outputs":[{"name":"","type":"uint8"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"cap","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[],"name":"unpause","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"_to","type":"address"},{"name":"_amount","type":"uint256"}],"name":"mint","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"_value","type":"uint256"}],"name":"burn","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"paused","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_spender","type":"address"},{"name":"_subtractedValue","type":"uint256"}],"name":"decreaseApproval","outputs":[{"name":"success","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"_owner","type":"address"}],"name":"balanceOf","outputs":[{"name":"balance","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[],"name":"finishMinting","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[],"name":"pause","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"owner","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"symbol","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_to","type":"address"},{"name":"_value","type":"uint256"}],"name":"transfer","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"_spender","type":"address"},{"name":"_addedValue","type":"uint256"}],"name":"increaseApproval","outputs":[{"name":"success","type":"bool"}],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"_owner","type":"address"},{"name":"_spender","type":"address"}],"name":"allowance","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"newOwner","type":"address"}],"name":"transferOwnership","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"inputs":[],"payable":false,"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"name":"burner","type":"address"},{"indexed":false,"name":"value","type":"uint256"}],"name":"Burn","type":"event"},{"anonymous":false,"inputs":[],"name":"Pause","type":"event"},{"anonymous":false,"inputs":[],"name":"Unpause","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"to","type":"address"},{"indexed":false,"name":"amount","type":"uint256"}],"name":"Mint","type":"event"},{"anonymous":false,"inputs":[],"name":"MintFinished","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"owner","type":"address"},{"indexed":true,"name":"spender","type":"address"},{"indexed":false,"name":"value","type":"uint256"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"from","type":"address"},{"indexed":true,"name":"to","type":"address"},{"indexed":false,"name":"value","type":"uint256"}],"name":"Transfer","type":"event"}];
     
    // 合约地址
    var contractAddress = "0x7FCCF800568747b178c6cBbe4Bf3d147df75ac61";
     
    // 账号
    var currentAccount = "0x4e9d5c58d8d6f02FFe5A6EF10CB804FfFB556bBb";
     
    // 定义合约
    var myContract = new web3.eth.Contract(contractAbi, contractAddress, {
        from: currentAccount, // default from address
        gasPrice: '10000000000' // default gas price in wei, 10 gwei in this case
    });
     
    // 查询以太币余额
    web3.eth.getBalance(currentAccount).then(console.log);
     
    // 查看某个账号的代币余额
    myContract.methods.balanceOf(contractAddress).call({from: currentAccount}, function(error, result){
        if(!error) {
            console.log(result);
        } else {
            console.log(error);
        }
    });

> 这里还可以查询代币的名称，符号，小数位，发行总量等等，因为代币合约一般都符合`ERC`标准，都有这些基本方法。甚至如果你有合约代码和`abi`，还可以调用合约的其他方法，当然调用有些方法需要权限及前置条件

// 获得代币名称
    myContract.methods.name().call({from: currentAccount}, function(error, result){
        if(!error) {
              console.log(result);
        } else {
          console.log(error);
        }
    });
     
    // 获取代币符号
    myContract.methods.symbol().call({from: currentAccount}, function(error, result){
        if(!error) {
          console.log(result);
         } else {
          console.log(error);
         }
    });
     
    // 获取代币总量
    myContract.methods.totalSupply().call({from: currentAccount}, function(error, result){
        if(!error) {
          console.log(result);
         } else {
          console.log(error);
         }
    });
     
    // 查看某个账号允许另一个账号可使用的代币数量
    myContract.methods.allowance(sender, spender).call({from: currentAccount}, function(error, result){
        if(!error) {
          console.log(result);
         } else {
          console.log(error);
         }
    });

## 在私链上转账以太币及代币 ##

// 以太币转账
    web3.eth.sendTransaction({
        from: currentAccount,
        to: receiverAccount,
        value: '1000000000000000'
    })
    .then(function(receipt){
        console.log(receipt);
    });
     
    // 代币转账
    myContract.methods.transfer(to, amount).send({from: currentAccount}), function(error, transactionHash){
        if(!error) {
           console.log('transactionHash is ' + transactionHash);
        } else {
           console.log(error);
        }
    });

## 在主链上转账以太币及代币 ##

> 上面的方法只适用于私链。因为你在私链的账户在本地是有私钥的。而在主链上要进行写入数据的方法，是需要获取账户的私钥并对交易进行签名的，所以要用到`web3.eth.sendSignedTransaction`方法-[文档][Link 1]

npm install ethereumjs-tx

以太币转账

// 引入ethereumjs-tx
    var Tx = require('ethereumjs-tx');
     
    // 以太币转账    
    // 先获取当前账号交易的nonce
    web3.eth.getTransactionCount(currentAccount, web3.eth.defaultBlock.pending).then(function(nonce){
     
        
        // 获取交易数据
        var txData = {
            // nonce每次++，以免覆盖之前pending中的交易
            nonce: web3.utils.toHex(nonce++),
            // 设置gasLimit和gasPrice
            gasLimit: web3.utils.toHex(99000),   
            gasPrice: web3.utils.toHex(10e9),  
            // 要转账的哪个账号  
            to: '0x3b11f5CAB8362807273e1680890A802c5F1B15a8',
            // 从哪个账号转
            from: currentAccount,
            // 0.001 以太币
            value: web3.utils.toHex(10e14),         
            data: ''
        }
     
        var tx = new Tx(txData);
     
        // 引入私钥，并转换为16进制
        const privateKey = new Buffer('your account privateKey', 'hex'); 
     
        // 用私钥签署交易
        tx.sign(privateKey);
     
        // 序列化
        var serializedTx = tx.serialize().toString('hex');
     
        web3.eth.sendSignedTransaction('0x' + serializedTx.toString('hex'), function(err, hash) {
            if (!err) {
                console.log(hash);
            } else {
                console.error(err);
            }
        });
    });

代币转账

// 补齐64位，不够前面用0补齐
    function addPreZero(num){
      var t = (num+'').length,
      s = '';
      for(var i=0; i<64-t; i++){
        s += '0';
      }
      return s+num;
    }
     
    web3.eth.getTransactionCount(currentAccount, web3.eth.defaultBlock.pending).then(function(nonce){
     
        // 获取交易数据
        var txData = {
            nonce: web3.utils.toHex(nonce++),
            gasLimit: web3.utils.toHex(99000),   
            gasPrice: web3.utils.toHex(10e9),
            // 注意这里是代币合约地址    
            to: contractAddress,
            from: currentAccount,
            // 调用合约转账value这里留空
            value: '0x00',         
            // data的组成，由：0x + 要调用的合约方法的function signature + 要传递的方法参数，每个参数都为64位(对transfer来说，第一个是接收人的地址去掉0x，第二个是代币数量的16进制表示，去掉前面0x，然后补齐为64位)
            data: '0x' + 'a9059cbb' + addPreZero('3b11f5CAB8362807273e1680890A802c5F1B15a8') + addPreZero(web3.utils.toHex(1000000000000000000).substr(2))
        }
     
        var tx = new Tx(txData);
     
        const privateKey = new Buffer('your account privateKey', 'hex'); 
     
        tx.sign(privateKey);
     
        var serializedTx = tx.serialize().toString('hex');
     
        web3.eth.sendSignedTransaction('0x' + serializedTx.toString('hex'), function(err, hash) {
            if (!err) {
                console.log(hash);
            } else {
                console.error(err);
            }
        });
    });

[https_etherscan.io]: https://etherscan.io
[Link 1]: https://web3js.readthedocs.io/en/v1.2.0/web3-eth.html#sendsignedtransaction