343-eth合约编译部署

我们先create-react-app
创建一个项目





然后写一个合约
lottery.sol





我们来安装一下合约的编译器
npm install solc@0.4.25 --save





然后来编译合约
compile.js

let fs = require('fs')
let solc = require('solc')

//1.读取合约
let lotteryInfo = fs.readFileSync('lottery.sol')
console.log(lotteryInfo)

//2.编译合约
let compileInfo = solc.compile(lotteryInfo.toString(),1)
console.log(compileInfo)

//3.导出abi
module.exports = compileInfo['contracts'][':Lottery']






我们安装一下web3
npm install web3 --save




然后启动巧克力ganache-cli
ganache-cli -h 127.0.0.1 -p 7545 -m "aaa bbb ccc..."




然后
部署合约
deploy.js

let {bytecode, interface} = require('./compile.js')
let Web3 = require('web3')

console.log(bytecode)
console.log(interface)

//1.实例化web3
let web3 = new Web3('http://127.0.0.1:7545')
console.log(web3.version)

//2.部署函数
let deploy = async() =>{
	//1.填写abi
	let contractInstance = new web3.eth.Contract(JSON.parse(interface))
	
	//2.填写bytecode
	let result = await contractInstance.deploy({
		data: bytecode,
		arguments: [],
	}).send({
		//3.send交易
		from: account0,
		gas: '100',
		value: 0,
	})
	
	//合约地址
	console.log(result.options.address)
}

deploy()









获取合约实例
loadInstance.js

let Web3 = require('web3')
let abi = [{abcabc...}]
let address = '0xabc...'

//1.实例化web3
let web3 = new Web3('http://127.0.0.1:7545')
console.log(web3.version)

//2.获取合约实例
let lotteryInstance = new web3.eth.Contract(abi, address)
module.exports = lotteryInstance









现在,在前端页面展示一下
打开App.js

import React, {Component} from 'react';
let loadInstance = require('./loadInstance.js')

class App extends Component{

	state={
		manager: ''
	}

	async componentWillMount(){
		let manager = await lotteryInstance.methods.manager().call()
		console.log(manager)
		
		//给状态变量赋值
		this.setState({
			manager: manager
		})
	}

	render(){
		return (
			<p>hello world</p>
			<p>manager : {this.state.manager}</p>
		);
	}
}

export default App;









合约交互