编写合约

打开ganache, 这个在本地启动了一个测试链，如下图片：

node_modules/.bin/ganache-cli

屏幕截图 2021-06-19 210334.png

创建投票合约， 创建一个文件Voting.sol, 内容如下

pragma solidity ^0.4.17;

contract Voting {
    mapping(bytes32 => uint8) public votesReceived;
    bytes32[] public candidateList;

    constructor(bytes32[] candidateNames) public {
        candidateList = candidateNames;
    }

    function totalVotesFor(bytes32 candidate) public view returns (uint8) {
        require(validCandidate(candidate));
        return votesReceived[candidate];
    }

    function voteForCandidate(bytes32 candidate) public {
        require(validCandidate(candidate));
        votesReceived[candidate] += 1;
    }

    function validCandidate(bytes32 candidate) public view returns (bool) {
        for (uint256 i = 0; i < candidateList.length; i++) {
            if (candidateList[i] == candidate) {
                return true;
            }
        }
        return false;
    }
}

打开node， 依次输入

Web3 = require('web3')
web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"));

//如下是测试是否连上了
web3.eth.getBalance('0xA8213aA010c9C3c09d7a547115c74145BE677FB1')
BigNumber { s: 1, e: 20, c: [ 1000000 ] }

读取代码，并进行编译

code = fs.readFileSync('Voting.sol').toString()
solc = require('solc')
compiledCode = solc.compile(code)