开发以太坊dapp首先可以用官方框架
安装truffle
npm install -g truffle
环境依赖
NodeJS v8.9.4 或 之后的版本 Windows, Linux or Mac OS X
安装过程中可能遇到问题解决办法如下：
安装命令：sudo npm install -g truffle 安装过程中可能遇到问题解决： sudo npm install -g n
sudo n stable 安装完成检车是否成功：truffle -v
接下来说一下怎么使用truffle 开发属于自己的dapp
一：创建相关文件夹下载模板
1.cd Voting 2.truffle unbox webpack
二：创建合约
cd contracts rm meta.sol Lib.sol vim Voting 把写好的代码拷贝到其中
三：修改模板配置文件（trufflevotingwebpack-boxmigrations2_deploy_contracts.js）
//const ConvertLib = artifacts.require("ConvertLib");
//const MetaCoin = artifacts.require("MetaCoin");
const Voting = artifacts.require("Voting");
module.exports = function(deployer) {
//deployer.deploy(ConvertLib);
//deployer.link(ConvertLib, MetaCoin);
//deployer.deploy(MetaCoin);
deployer.deploy(Voting,["0x4100000000000000000000000000000000000000000000000000000000000000","0x4200000000000000000000000000000000000000000000000000000000000000"]);
};
四：编译合约
cd trufflevotingwebpack-box truffle compile
五：部署合约
启动ganache-cli（如果失败，则重新安装npm install -g ganache-cli）
注意：启动以太坊模拟区块链，默认端口8545
// const HDWallet = require('truffle-hdwallet-provider');
// const infuraKey = "fj4jll3k.....";
//
// const fs = require('fs');
// const mnemonic = fs.readFileSync(".secret").toString().trim();
module.exports = {
networks: {
// Useful for testing. The `development` name is special - truffle uses it by default
// if it's defined here and no other network is specified at the command line.
// You should run a client (like ganache-cli, geth or parity) in a separate terminal
// tab if you use this network and you must also set the `host`, `port` and `network_id`
// options below to some value.
//
development: {
host: "localhost", // Localhost (default: none)
port: 8545, // Standard Ethereum port (default: none)
network_id: "*", // Any network (default: none)
},
//develop: {
// port: 8545
//},
// Another network with more advanced options...
// advanced: {
// port: 8777, // Custom port
// network_id: 1342, // Custom network
// gas: 8500000, // Gas sent with each transaction (default: ~6700000)
// gasPrice: 20000000000, // 20 gwei (in wei) (default: 100 gwei)
// from: , // Account to send txs from (default: accounts[0])
// websockets: true // Enable EventEmitter interface for web3 (default: false)
// },
// Useful for deploying to a public network.
// NB: It's important to wrap the provider as a function.
// ropsten: {
// provider: () => new HDWalletProvider(mnemonic, `https://ropsten.infura.io/v3/YOUR-PROJECT-ID`),
// network_id: 3, // Ropsten's id
// gas: 5500000, // Ropsten has a lower block limit than mainnet
// confirmations: 2, // # of confs to wait between deployments. (default: 0)
// timeoutBlocks: 200, // # of blocks before a deployment times out (minimum/default: 50)
// skipDryRun: true // Skip dry run before migrations? (default: false for public nets )
// },
// Useful for private networks
// private: {
// provider: () => new HDWalletProvider(mnemonic, `https://network.io`),
// network_id: 2111, // This network is yours, in the cloud.
// production: true // Treats this network as if it was a public net. (default: false)
// }
},
// Set default mocha options here, use special reporters etc.
mocha: {
// timeout: 100000
},
// Configure your compilers
compilers: {
solc: {
// version: "0.5.1", // Fetch exact version from solc-bin (default: truffle's version)
// docker: true, // Use "0.5.1" you've installed locally with docker (default: false)
// settings: { // See the solidity docs for advice about optimization and evmVersion
// optimizer: {
// enabled: false,
// runs: 200
// },
// evmVersion: "byzantium"
// }
}
}
}
部署
truffle migrate
部署完检验方法
打开truffle console控制台
truffle console let instance = await Voting.deployed() instance
六：修改前端页面
MyVoting 投票DAPP测试
MyVoting 投票DAPP测试
Jerry : loding... tickets
Amy : loding... tickets
七：修改index.js
import Web3 from "web3";
import votingArtifact from "../../build/contracts/Voting.json";
const aInBytes32="0x4100000000000000000000000000000000000000000000000000000000000000";
const bInBytes32="0x4200000000000000000000000000000000000000000000000000000000000000";
const App = {
web3: null,
account: null,
voting: null,
start: async function() {
const { web3 } = this;
try {
// get contract instance
const networkId = await web3.eth.net.getId();
const deployedNetwork = votingArtifact.networks[networkId];
this.voting = new web3.eth.Contract(
votingArtifact.abi,
deployedNetwork.address,
);
// get accounts
const accounts = await web3.eth.getAccounts();
this.account = accounts[0];
//this.refreshBalance();
this.ready();
} catch (error) {
console.error("Could not connect to contract or chain.");
}
},
refresh : async function (id,nameInBytes32){
const {LookForCandidate} =this.voting.methods;
const tickets = await LookForCandidate(nameInBytes32).call();
const element = document.getElementById(id);
element.innerHTML = tickets.toString();
},
ready: async function(){
try{
this.refresh("Jerry",aInBytes32);
this.refresh("Amy",bInBytes32);
}catch(err){
console.log(err)
}
},
voteForCandidate: async function(){
try{
const {voteForCandidate} = this.voting.methods;
const candidateName = document.getElementById("candidate").value;
console.log(candidateName);
if(candidateName == "Jerry"){
await voteForCandidate(aInBytes32).send({from:this.account});
this.refresh("Jerry",aInBytes32);
}else if(candidateName == "Amy"){
await voteForCandidate(bInBytes32).send({from:this.account});
this.refresh("Amy",bInBytes32);
}
}catch(err){
console.info(err)
}
}
};
window.App = App;
window.addEventListener("load", function() {
if (window.ethereum) {
// use MetaMask's provider
App.web3 = new Web3(window.ethereum);
window.ethereum.enable(); // get permission to access accounts
} else {
console.warn(
"No web3 detected. Falling back to http://127.0.0.1:8545. You should remove this fallback when you deploy live",
);
// fallback - use your fallback strategy (local node / hosted node + in-dapp id mgmt / fail)
App.web3 = new Web3(
new Web3.providers.HttpProvider("http://127.0.0.1:8545"),
);
}
App.start();
});
八：运行即可
npm run dev
浏览器输入对应网站
