执行写函数调用,需要签署交易、广播交易,就像前面章节中一样。
app.js
完整代码如下所示:
var Tx = require('ethereumjs-tx').Transaction
const Web3 = require('web3')
const web3 = new Web3('https://ropsten.infura.io/v3/YOUR_INFURA_API_KEY')
const account1 = '0xf4Ab5314ee8d7AA0eB00b366c52cEEccC62d6B4B' // Your account address 1
const account2 = '0xff96B8B43ECd6C49805747F94747bFfa3A960b69' // Your account address 2
const pk1 = 'b75e2bcaec74857cf9bb6636d66a04784d4c0fcfd908f4a2bc213428eba5af0d' // 实际项目中应该从process.env.PRIVATE_KEY_1中读取
const pk2 = 'ac0adfdbaeb0770a479e79aac78779d82fdc2f9262e0c8f751ae70fb63ef6196' // 实际项目中应该从process.env.PRIVATE_KEY_2中读取
const privateKey1 = Buffer.from(pk1, 'hex')
const privateKey2 = Buffer.from(pk2, 'hex')
// 读取已部署的契约 -- 从Etherscan获取地址
const contractAddress = '0x30951343d6d80d2c94897f1a81c53cc030aef879'
const contractABI = [
{
"constant": false,
"inputs": [
{
"internalType": "string",
"name": "_value",
"type": "string"
}
],
"name": "set",
"outputs": [],
"payable": false,
"stateMutability": "nonpayable",
"type": "function"
},
{
"constant": true,
"inputs": [],
"name": "get",
"outputs": [
{
"internalType": "string",
"name": "",
"type": "string"
}
],
"payable": false,
"stateMutability": "view",
"type": "function"
},
{
"inputs": [],
"payable": false,
"stateMutability": "nonpayable",
"type": "constructor"
}
]
const contract = new web3.eth.Contract(contractABI, contractAddress)
web3.eth.getTransactionCount(account1, (err, txCount) => {
// 创建交易对象
const txObject = {
nonce: web3.utils.toHex(txCount),
gasLimit: web3.utils.toHex(8000000),
gasPrice: web3.utils.toHex(web3.utils.toWei('10', 'gwei')),
to: contractAddress,
data: contract.methods.set("qikegu").encodeABI()
}
// 签署交易
const tx = new Tx(txObject, { chain: 'ropsten', hardfork: 'petersburg' })
tx.sign(privateKey1)
const serializedTx = tx.serialize()
const raw = '0x' + serializedTx.toString('hex')
// 广播交易
web3.eth.sendSignedTransaction(raw, (err, txHash) => {
console.log('txHash:', txHash)
// 可以去ropsten.etherscan.io查看交易详情
})
})
调用合约get()函数读取原来的value值
在执行合约set()
函数调用之前,我们先看看原来的value值,新建一个get_val.js
文件:
var Tx = require('ethereumjs-tx').Transaction
const Web3 = require('web3')
const web3 = new Web3('https://ropsten.infura.io/v3/YOUR_INFURA_API_KEY')
const account1 = '0xf4Ab5314ee8d7AA0eB00b366c52cEEccC62d6B4B' // Your account address 1
const account2 = '0xff96B8B43ECd6C49805747F94747bFfa3A960b69' // Your account address 2
const pk1 = 'b75e2bcaec74857cf9bb6636d66a04784d4c0fcfd908f4a2bc213428eba5af0d' // 实际项目中应该从process.env.PRIVATE_KEY_1中读取
const pk2 = 'ac0adfdbaeb0770a479e79aac78779d82fdc2f9262e0c8f751ae70fb63ef6196' // 实际项目中应该从process.env.PRIVATE_KEY_2中读取
const privateKey1 = Buffer.from(pk1, 'hex')
const privateKey2 = Buffer.from(pk2, 'hex')
// 读取已部署的契约 -- 从Etherscan获取地址
const contractAddress = '0x30951343d6d80d2c94897f1a81c53cc030aef879'
const contractABI = [
{
"constant": false,
"inputs": [
{
"internalType": "string",
"name": "_value",
"type": "string"
}
],
"name": "set",
"outputs": [],
"payable": false,
"stateMutability": "nonpayable",
"type": "function"
},
{
"constant": true,
"inputs": [],
"name": "get",
"outputs": [
{
"internalType": "string",
"name": "",
"type": "string"
}
],
"payable": false,
"stateMutability": "view",
"type": "function"
},
{
"inputs": [],
"payable": false,
"stateMutability": "nonpayable",
"type": "constructor"
}
]
const contract = new web3.eth.Contract(contractABI, contractAddress)
// 读取val值
contract.methods.get().call((err, val) => {
console.log({ err, val })
})
运行get_val.js:
$ node get_val
输出
myValue
执行app.js
运行app.js:
$ node app
输出
txHash: 0xcb538e0e2e08d3b352aeef34d0c31140f022d1ef456b89edb39972536dba259e
可以去etherscan,查看交易详情。
再次调用合约get()函数读取改变后的value值
过5分钟左右,让交易写入区块链。然后运行get_val.js:
$ node get_val
输出
{ err: null, val: 'qikegu' }
可以看到合约中value值,已经被成功改变。