安装环境

Truffle && Ganache

Truffle是最全面的智能合约开发套件

• 内置智能合约编译、链接、部署和二进制管理。

• 使用断点、变量分析和步骤功能进行高级调试。

• Truffle基于JavaScript编写，可以在智能合约中使用console.log进行调试

• 通过MetaMask和Truffle Dashboard进行部署和交易，保护你的助记词。

• 在Truffle环境中执行脚本的外部脚本运行器。

• 用于快速开发的自动化合约测试。

• 使用NPM进行包管理，使用ERC190标准

• 可编写脚本、可扩展的部署和迁移架构

• 可用于合同通信的交互式控制台

# 安装node
nvm install 18# 安装Truffle
npm install -g truffle
# 查看Truffle版本
truffle version# 安卓ganache
https://trufflesuite.com/docs/ganache/quickstart/

安装IDE插件

https://marketplace.visualstudio.com/items?itemName=trufflesuite-csi.truffle-vscode

https://trufflesuite.com/blog/build-on-web3-with-truffle-vs-code-extension/

vscode安装Truffle for VS Code

使用说明

#新建项目
make dir fcoin
cd fcoin
truffle init

init后会创建

• Contracts 文件夹

• Migrations 文件夹

• Tests 文件夹

• truffle-config.js Truffle Configuration 文件

配置文件truffle-config.js 里的network是要部署的链。其中"development"部分是命令"truffle develop"对应的网络

    development: {host: "127.0.0.1",     // Localhost (default: none)port: 9545,            // Standard Ethereum port (default: none)network_id: "*",       // Any network (default: none)},

可以跟ganache对应

开始编码

参考：https://blog.whiteprompt.com/solidity-development-environment-setup-explained-b4e613503f8d

合约

写个sol代码Counter.sol

// SPDX-License-Identifier: MIT
pragma solidity >=0.4.22 <0.9.0;
contract Counter {uint private count;constructor(uint _initialCount) public {count = _initialCount;}function incrementBy(uint _increment) public {count = count + _increment;}function getCount() public view returns (uint) {return count;}
}

migrations

执行命令

ruffle create migration deploy_counter

增加部署代码

const Counter = artifacts.require('Counter');module.exports = function(_deployer) {// Use deployer to state migration tasks._deployer.deploy(Counter, 1);
};

部署

truffle migrate

部署成功，合约地址

> contract address: 0xA54d15330a0fFA3C2578c72aa0A3Be537d485D27

交互

#注意，你已经打开了 truffle develop#初始化，调用合约
let instance = await Counter.at("0xA54d15330a0fFA3C2578c72aa0A3Be537d485D27")

#获取合约里的初始化数字
instance.getCount()

返回内容，word后面的1是值

BN { negative: 0, words: [ 1, <1 empty item> ], length: 1, red: null }

instance.incrementBy(88)
# 返回89
instance.getCount()

其他案例

https://blog.csdn.net/VictorXSS/article/details/127852997

这个文档中，要注意migrations里，要加2_deploy_contracts.js

// SPDX-License-Identifier: MIT
pragma solidity >=0.4.22 <0.9.0;contract Pair{string private _name;uint private _liquidity;constructor(string memory name){_name = name;}function addLiquidity(uint amount) public {_liquidity+=amount;}function getLiquidity() public view returns(uint){return _liquidity;}function getName() public view returns(string memory){return _name;}}contract Dex {address private _owner;uint private _index = 0;mapping(address => Pair) private _pairs;mapping(uint => address) private _indexs;modifier onlyOwner(){require(msg.sender == _owner,"must be owner");_;}event PairCreated(string name, address pairAddress);event AddLiquidity(address pairAddress, uint liquidity);function createPair(string memory name) public {Pair pair = new Pair(name);_pairs[address(pair)] = pair;_indexs[_index] = address(pair);_index++;emit PairCreated(name, address(pair));}function addLiquidity(address pairedAddress,uint liquidity) public {_pairs[pairedAddress].addLiquidity(liquidity);emit AddLiquidity(pairedAddress,liquidity);}function getCount() public view returns(uint){return _index;}function pairAddress(uint index) public view returns(address){return _indexs[index];}function getPairName(address pairedAddress) public view returns(string memory){return _pairs[pairedAddress].getName();}function getLiquidity(address pairedAddress) public view returns(uint liquidity){return _pairs[pairedAddress].getLiquidity();}
}

核心代码

# solidity 里的代码
emit PairCreated(name, address(pair));emit AddLiquidity(pairAddress,liquidity);

# subgraph.yaml    eventHandlers:- event: PairCreated(string,address)handler: handleNewPairCreated- event: AddLiquidity(address,uint256)handler: handleAddLiquidity

import {AddLiquidity, PairCreated} from '../generated/study/Dex'
import {Pair} from '../generated/schema'export function handleNewPairCreated(event: PairCreated): void {let pair = new Pair(event.params.pairAddress.toHexString())pair.displayName = event.params.namepair.liquidity = 0pair.save()
}export function handleAddLiquidity(event: AddLiquidity): void {let id = event.params.pairAddress.toHexString()let pair = Pair.load(id)if (pair == null) {return}pair.liquidity += event.params.liquidity.toI32()pair.save()
}

• PairCreated 是solidity里的emit方法

• handleNewPairCreated 是mapping.ts 里的代码

• 当solidity里的PairCreated 被调用时，会触发handleNewPairCreated，保存数据。保存数据可以是数据库或者文件

• 触发是由provider里提供的

• provider 是Web3 provider is a website running geth or parity node which talks to Ethereum network.

调用

https://blog.csdn.net/qq_41882147/article/details/82966783

参考

https://blog.csdn.net/u013705066/article/details/123573546

https://blog.quicknode.com/the-importance-of-web3-provider-redundancy

https://ethereum.stackexchange.com/questions/31218/what-are-providers-in-the-ethereum

https://techfi.tech/introduction-to-the-graph-the-google-of-web3/

https://thegraph.academy/developers/local-development/

https://blog.whiteprompt.com/solidity-development-environment-setup-explained-b4e613503f8d?gi=cac56d9e3cc4