以太坊之DAPP开发（完整例⼦）
开发以太坊dapp⾸先可以⽤官⽅框架
npm install -g truffle
环境依赖
NodeJS v8.9.4 或之后的版本
Windows, Linux or Mac OS X
两面瑶
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河南金蝉养殖
1.cd Voting
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（truffle\voting\webpack-box\migrations\2_deploy_contracts.js）
//const ConvertLib = quire("ConvertLib");
//const MetaCoin = quire("MetaCoin");
const Voting = quire("Voting");
//deployer.deploy(ConvertLib);
//deployer.link(ConvertLib, MetaCoin);
//deployer.deploy(MetaCoin);
deployer.deploy(Voting,["0x4100000000000000000000000000000000000000000000000000000000000000","0x42000000000000000000000000000000 00000000000000000000000000000000"]);
};
四：编译合约
cd truffle\voting\webpack-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
/**
* Use this file to configure your truffle project. It's seeded with some
* common settings for different networks and features like migrations,
* compilation and testing. Uncomment the ones you need or modify
* them to suit your project as necessary.
*
* More information about configuration can be found at:
*
*
* truffleframework/docs/advanced/configuration
*
* To deploy via Infura you'll need a wallet provider (like truffle-hdwallet-provider)
* to sign your transactions before they're sent to a remote public node. Infura accounts
* are available for free at: infura.io/register.
*
* You'll also need a mnemonic - the twelve word phrase the wallet uses to generate
* public/private key pairs. If you're publishing your code to GitHub make sure you load this
* phrase from a file you've .gitignored so it doesn't accidentally become public.
*
*/
// const HDWallet = require('truffle-hdwallet-provider');
// const infuraKey = "";
//
// const fs = require('fs');
// const mnemonic = fs.readFileSync(".secret").toString().trim();
/**
* Networks define how you connect to your ethereum client and let you set the
* defaults web3 uses to send transactions. If you don't specify one truffle
* will spin up a development blockchain for you on port 9545 when you
* run `develop` or `test`. You can ask a truffle command to use a specific
* network from the command line, e.g
*
* $ truffle test --network <network-name>
*/
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: {
/
/ 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: <address>, // 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, `ropsten.infura.io/v3/YOUR-PROJECT-ID`), // network_id: 3, // Ropsten's id
// gas: 5500000, // Ropsten has a lower block limit than mainnet
计算机及其应用// 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, `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
辽宁中医药大学图书馆打开truffle console控制台
truffle console
let instance =await Voting.deployed()
instance
六：修改前端页⾯
<!DOCTYPE html>
<html>
<head>
<title>MyVoting 投票DAPP测试</title>
</head>
<style>
input {
display: block;
margin-bottom:12px;
}
</style>
<body>
<h1>MyVoting 投票DAPP测试</h1>
<p>Jerry :<strong id ="Jerry"&</strong> tickets</p>
<p>Amy :<strong id ="Amy"&</strong> tickets</p>
<input type="text" id="candidate"/>
<button onclick="App.voteForCandidate()">vote</button>
<script src="index.js"></script>
</body>
</html>
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 =h.getId();
const deployedNetwork = votingArtifactworks[networkId];
this.voting =h.Contract(
votingArtifact.abi,
deployedNetwork.address,
);
/
/ get accounts
const accounts =h.getAccounts();
this.account = accounts[0];
//freshBalance();
}catch(error){
<("Could not connect to contract or chain.");
}
},
refresh:async function(id,nameInBytes32){
const{LookForCandidate}=hods;
const tickets =await LookForCandidate(nameInBytes32).call();
const element = ElementById(id);
element.innerHTML = String();
},
ready:async function(){
try{
达夫fresh("Amy",bInBytes32);
}catch(err){
console.log(err)
}
},
voteForCandidate:async function(){
try{
const{voteForCandidate}=hods;
const candidateName = ElementById("candidate").value;
console.log(candidateName);
if(candidateName =="Jerry"){
await voteForCandidate(aInBytes32).send({from:this.account});
}else if(candidateName =="Amy"){
await voteForCandidate(bInBytes32).send({from:this.account});
}
}catch(err){
console.info(err)
}
}
};
};
window.App = App;
window.addEventListener("load",function(){
hereum){
/
/ use MetaMask's provider
App.web3 =new hereum);
}else{
console.warn(
"No web3 detected. Falling back to 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(
笛卡儿积
new Web3.providers.HttpProvider("127.0.0.1:8545"),
);
}
App.start();
});
⼋：运⾏即可
npm run dev
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