以太坊开发中ethers库的使用

eip-155定义的eth 的chainID

CHAIN_ID	Chain(s)
1	Ethereum mainnet
2	Morden (disused), Expanse mainnet
3	Ropsten
4	Rinkeby
5	Goerli
42	Kovan
1337	Geth private chains (default)

ethers.utils.HDNode.isValidMnemonic（）：验证助记词是否有效
ethers.utils.getAddress（）：转换为checkSum地址

1. send方法后面可写入rpc调用方法名(eth标准方法)，后面跟参数

personal_importRawKey
let lockStatus = await rpcProvider.send(“personal_lockAccount”, address)

2.查询token余额

    const getBalance_USDT = async () => {const contract = new ethers.Contract(USDTaddress, USDTabi, rpcProvider);const balance = await contract.balanceOf(address);return balance.toString();};

//6为token有效小数位。查到的余额除以有效小数位才是实际余额
let actuBalUSDT = ethers.utils.formatUnits(queryBalUSDT, 6)

3.查询eth余额

   let pendingBal = await rpcProvider.getBalance(address, "pending")

查询不同状态的余额”latest”（已经确认了的）, “earliest”（创世区块的）， “pending”（包含未确认的交易的余额）

4.utils

//去除地址前面的0位
let address = ethers.utils.hexStripZeros(addressQuery)
// 相当于从wei到ether
let numberOfDecimals = 18;
let BNBbal = ethers.utils.parseUnits(queryBalBNB, numberOfDecimals);

5.发送eth交易

let wallet = new ethers.Wallet(privateKey, provider);
let amount = ethers.utils.parseEther(amount);
//let nonce = await rpcProvider.getTransactionCount(address, "pending")
let nonce = await wallet.getTransactionCount();
let gasPrice=await provider.getGasPrice();let tx = {nonce: nonce,gasLimit: 21000,gasPrice: ethers.utils.bigNumberify(gasPrice),to: toAddress,chainId: chainId,value: amount,data: ""};// let signTx = await wallet.sign(tx)// let resp = await rpcProvider.sendTransaction(signTx)
或
let resp = await wallet.sendTransaction(tx);

6.发送token交易

 let numberOfTokens = ethers.utils.parseUnits(amount, decims);// 先计算transfer 需要的gas 消耗量，这一步有默认值，非必须。let gas = await contract.estimate.transfer(toAddress, numberOfTokens)let gasP = await rpcProvider.getGasPrice()// 必须关联一个有过签名钱包对象let contractWithSigner = contract.connect(wallet);//  发起交易，前面2个参数是函数的参数，第3个是交易参数let tx = await contractWithSigner.transfer(toAddress, numberOfTokens, {nonce: nonce,gasLimit: gas,gasPrice: ethers.utils.bigNumberify(gasP) ,chainId: chainId})

7.获取节点所有账户的余额

async function checkAllBalances() {let e = await rpcProvider.listAccounts()for (let i = 0; i < e.length; i++) {let bal = await rpcProvider.getBalance(e[i])let balance = ethers.utils.formatEther(bal)console.log(`${e[i]}: `+balance)}
}
checkAllBalances();

8. 单位转换

       // 转换cost为 wei单位的BigNumber类型const costWei = ethers.utils.bigNumberify(21000).mul('0x3b9aca00')console.log(costWei);// 转换cost为ether单位的一般表示（可读的10进制）const costEther = ethers.utils.formatEther(costWei)console.log(costEther);// 转换cost为ether单位的BigNumber类型const costBigNumber = ethers.utils.parseEther(costEther);console.log(costBigNumber);// 余额减去花费作为 新的转入余额,const amount = pendingBal.sub(costBigNumber)console.log(ethers.utils.formatEther(amount));