通过Web3大家可以很方便的使用js，java，python 库转ERC20代币。作为世界上最好语言的php的web3库 sc0vu/web3.php只支持私有节点转账，无法使用公共节点转账。因此我们要使用另外一个库进行开发以太坊相关的。
本文源码解析，文章的所有内容均不构成任何投资比特币或其他数字货币的意见和建议，也不赞成个人炒作任何数字货币！

安装

在composer项目中安装kgs/web3

composer require kgs/web3

Web3操作

kgs/web3封装了常用的json_rpc函数

$web3 = new Web3('https://kovan.infura.io/v3/9aa3d95b3bc440fa88ea12eaa4456161');
var_dump($web3->accounts()); //查看私有节点的账户

echo $web3->gasPrice(); //输出当前的gas费用
$address = "0xdB7D1B76D262D31c51d740C6fb98047B8498D851";
echo Utils::hexToDec($web3->getBalance($address)); //输出账户的以太坊余额

钱包操作

$key = "e872122c04df93040ede8996c0e738f35a0ea44e77642d97eb5c3deedbdd4201"; 
$wallet =Wallet::createByPrivate($key); //使用私钥创建钱包
echo $wallet->getAddress(); //输出钱包的地址
//0xdb7d1b76d262d31c51d740c6fb98047b8498d851
$wallet = Wallet::create();//生成一个新的钱包
echo $wallet->getAddress(); //输出钱包的地址
echo $wallet->getPrivateKey(); //输出钱包的私钥

合约操作

//要转账钱包的私钥
$key = "e872122c04df93040ede8996c0e738f35a0ea44e77642d97eb5c3deedbdd4201"; 
//erc20的abi
$abi = '[{"inputs":[{"internalType":"string","name":"name","type":"string"},{"internalType":"string","name":"symbol","type":"string"}],"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":"from","type":"address"},{"indexed":true,"internalType":"address","name":"to","type":"address"},{"indexed":false,"internalType":"uint256","name":"value","type":"uint256"}],"name":"Transfer","type":"event"},{"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":[],"name":"decimals","outputs":[{"internalType":"uint8","name":"","type":"uint8"}],"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":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"addedValue","type":"uint256"}],"name":"increaseAllowance","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"name","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"symbol","outputs":[{"internalType":"string","name":"","type":"string"}],"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"}]';
//根据私钥创建钱包
$wallet =Wallet::createByPrivate($key);
//选择以太坊的接入节点，这里用的测试网，转的测试代币
$web3 = new Web3('https://kovan.infura.io/v3/9aa3d95b3bc440fa88ea12eaa4456161');
//合约的地址，即erc20代币的地址
$contractAddress='0x7ef08Db1E4121b71177B828d5b5ff7a1BCB8305D';
//根据web3，abi，以及合于地址初始化合约
$contract = Contract::at($web3,$abi,$contractAddress);
//接受转账的地址
$toAccount = "0x6aba7cd6750225f9d732a256F0f334916C866264";
//转账的数量，这里转一个代币，根据erc20的位数进行灵活调整
$amount =\Web3\Utils::ethToWei(1);
//调用转账方法，返回交易哈希
$res =$contract->send($wallet,'transfer',[$toAccount,]);
echo $res;
//0x43b287554146748780d00af8c7d9d42c499ba03759b759f0f4244b072ec0cab2y
//查询接收的地址拥有多少代币
$res =$contract->call('balanceOf',[$toAccount]);