简单介绍

官网传送门 Truffle是针对基于以太坊的Solidity语言的一套开发框架。本身基于Javascript，使用以太坊虚拟机（EVM）的世界一流的开发环境，用于区块链的测试框架和资产管道，旨在简化开发人员的生活。

安装truffle

安装前提：

预装nodejs

1.全局安装

npm install -g truffle

建立软链接

ln -s   /opt/node-v10.16.0-linux-x64/bin/truffle   /usr/local/bin/truffle

2.单个项目安装

npm install truffle

3.查看版本号

truffle version

4.安装成功

构建应用

快速开始 https://www.trufflesuite.com/docs/truffle/quickstart

创建项目

mkdir  simple-dapp

初始化项目

truffle init

Note: You can use the truffle unbox <box-name> command to download any of the other Truffle Boxes.

Note: To create a bare Truffle project with no smart contracts included, use truffle init.

本次采用基于webpack的box来构建

truffle unbox webpack

项目目录结构：

app/:Diretory for app
contracts/: Directory for Solidity contracts
migrations/: Directory for scriptable deployment files
test/: Directory for test files for testing your application and contracts
truffle-config.js: Truffle configuration file

创建合约：位于contracts文件夹下

pragma solidity >=0.4.21 <0.7.0;

contract Voting {

    //候选人得票数目

    mapping (bytes32=>uint8) public votesReceived;

    //候选人

    bytes32[] public candidateList;

    //构造器

    constructor(bytes32[] memory candidateNames) public {

        candidateList = candidateNames;

    }

    //查询投票数目

    function totalVotesFor(bytes32 candidate) view public returns (uint8){

        //非空校验

        require(validCandidate(candidate));

        return votesReceived[candidate];

    }

    //投票

    function VotingTo(bytes32 candidate) public {

        //非空校验

        require(validCandidate(candidate));

        //add

        votesReceived[candidate]+=1;

    }

    //校验

    function validCandidate(bytes32 candidate) view public returns (bool){

        for(uint i = 0;i<candidateList.length;i++){

            if(candidateList[i]==candidate){

                return true;

            }

        }

        return false;

    }

}

创建迁移文件：位于migrations文件夹下

const voting = artifacts.require('../contracts/Voting.sol')

module.exports = function (deployer) {

    deployer.deploy(voting,['Mikey','Leo','Don'].map(x=>web3.utils.asciiToHex(x)),{gas:2900000});

}

3_deploy_voting.js

编译智能合约

truffle compile

生成json文件

启动truffle的开发者模式

truffle develop

部署智能合约

migrate

Starting migrations...

======================

> Network name:    'develop'

> Network id:      5777

> Block gas limit: 0x6691b7

1_initial_migration.js

======================

   Deploying 'Migrations'

   ----------------------

   > transaction hash:    0x5d23f5f2452d41a20ee56b238efb21c9c81cb04e0105c874e5a26528538476e5

   > Blocks: 0            Seconds: 0

   > contract address:    0xD97313Cb13D2d39Bd8CD2CB6f3606aaCB89fa1Ad

   > block number:        13

   > block timestamp:     1578995366

   > account:             0x9c29d178Ba516574E372e3cf5Eda833359F4114F

   > balance:             99.96269208

   > gas used:            263741

   > gas price:           20 gwei

   > value sent:          0 ETH

   > total cost:          0.00527482 ETH

   > Saving migration to chain.

   > Saving artifacts

   -------------------------------------

   > Total cost:          0.00527482 ETH

2_deploy_contracts.js

=====================

   Deploying 'ConvertLib'

   ----------------------

   > transaction hash:    0x71bc728418b983c24aa541ffebffc8b2eafa53f1f5754e8a800a8f5688947069

   > Blocks: 0            Seconds: 0

   > contract address:    0x7caC31cFfE12a8A4D7F7bD83a97e3AF0E99206CE

   > block number:        15

   > block timestamp:     1578995366

   > account:             0x9c29d178Ba516574E372e3cf5Eda833359F4114F

   > balance:             99.95973214

   > gas used:            105974

   > gas price:           20 gwei

   > value sent:          0 ETH

   > total cost:          0.00211948 ETH

   Linking

   -------

   * Contract: MetaCoin <--> Library: ConvertLib (at address: 0x7caC31cFfE12a8A4D7F7bD83a97e3AF0E99206CE)

   Deploying 'MetaCoin'

   --------------------

   > transaction hash:    0x36bef9d0355bfcf5fd0fad5fd69574b9be37117b92883f03d1e76877cc07e045

   > Blocks: 0            Seconds: 0

   > contract address:    0xaAd2C9659fec947A764b244E37A281d219fb0a21

   > block number:        16

   > block timestamp:     1578995366

   > account:             0x9c29d178Ba516574E372e3cf5Eda833359F4114F

   > balance:             99.9529182

   > gas used:            340697

   > gas price:           20 gwei

   > value sent:          0 ETH

   > total cost:          0.00681394 ETH

   > Saving migration to chain.

   > Saving artifacts

   -------------------------------------

   > Total cost:          0.00893342 ETH

3_initial_voting.js

===================

   Deploying 'Voting'

   ------------------

   > transaction hash:    0x0a5c69ce8595788ef70513f2533af7f7a2c230525d50d68abaf30e49fed2c2ff

   > Blocks: 0            Seconds: 0

   > contract address:    0xdafBED4742Ff4b2bC17f0908D2E97DfA644B5417

   > block number:        18

   > block timestamp:     1578995366

   > account:             0x9c29d178Ba516574E372e3cf5Eda833359F4114F

   > balance:             99.94517058

   > gas used:            360358

   > gas price:           20 gwei

   > value sent:          0 ETH

   > total cost:          0.00720716 ETH

   > Saving migration to chain.

   > Saving artifacts

   -------------------------------------

   > Total cost:          0.00720716 ETH

Summary

=======

> Total deployments:   4

> Final cost:          0.0214154 ETH

truffle(develop)>

输出结果

部署成功

构建DApp

import Web3 from "web3";

import metaCoinArtifact from "../../build/contracts/MetaCoin.json";

const App = {

  web3: null,

  account: null,

  meta: null,

  start: async function() {

    const { web3 } = this;

    try {

      // get contract instance

      const networkId = await web3.eth.net.getId();

      const deployedNetwork = metaCoinArtifact.networks[networkId];

      this.meta = new web3.eth.Contract(

        metaCoinArtifact.abi,

        deployedNetwork.address,

      );

      // get accounts

      const accounts = await web3.eth.getAccounts();

      this.account = accounts[0];

      this.refreshBalance();

    } catch (error) {

      console.error("Could not connect to contract or chain.");

    }

  },

  refreshBalance: async function() {

    const { getBalance } = this.meta.methods;

    const balance = await getBalance(this.account).call();

    const balanceElement = document.getElementsByClassName("balance")[0];

    balanceElement.innerHTML = balance;

  },

  sendCoin: async function() {

    const amount = parseInt(document.getElementById("amount").value);

    const receiver = document.getElementById("receiver").value;

    this.setStatus("Initiating transaction... (please wait)");

    const { sendCoin } = this.meta.methods;

    await sendCoin(receiver, amount).send({ from: this.account });

    this.setStatus("Transaction complete!");

    this.refreshBalance();

  },

  setStatus: function(message) {

    const status = document.getElementById("status");

    status.innerHTML = message;

  },

};

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();

});

index.js

巴特西

Truffle 快速构建 DApp