区块链

引言 Web3和区块链技术正在重塑互联网的形态。本文将深入探讨智能合约开发、DeFi协议、NFT等核心主题，帮助开发者进入Web3世界。 一、Solidity智能合约 1.1 基础合约结构 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 // SPDX-License-Identifier: MIT pragma solidity ^0.8.20; import "@openzeppelin/contracts/token/ERC20/ERC20.sol"; import "@openzeppelin/contracts/access/Ownable.sol"; contract MyToken is ERC20, Ownable { uint256 public constant MAX_SUPPLY = 1_000_000_000 * 10**18; constructor() ERC20("MyToken", "MTK") { _mint(msg.sender, MAX_SUPPLY); } function mint(address to, uint256 amount) public onlyOwner { _mint(to, amount); } function burn(uint256 amount) public { _burn(msg.sender, amount); } } 1.2 安全最佳实践 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 // ========== 重入攻击防护 ========== contract ReentrancyGuard { bool private locked; modifier noReentrant() { require(!locked, "Reentrant call"); locked = true; _; locked = false; } function withdraw() external noReentrant { // ... } } // ========== 访问控制 ========== contract AccessControl { mapping(address => bool) public admins; modifier onlyAdmin() { require(admins[msg.sender], "Not admin"); _; } function addAdmin(address admin) external onlyAdmin { admins[admin] = true; } } // ========== 安全数学运算 ========== library SafeMath { function add(uint256 a, uint256 b) internal pure returns (uint256) { require(a + b >= a, "Overflow"); return a + b; } function sub(uint256 a, uint256 b) internal pure returns (uint256) { require(a >= b, "Underflow"); return a - b; } } 二、DeFi协议开发 2.1 AMM交换池 1 2 3 4 5 6 7 8 9 10 11 12 contract AMMPool { uint256 public reserve0; uint256 public reserve1; function addLiquidity(uint256 amount0, uint256 amount1) external { // ... } function swap(uint256 amount0In, uint256 amount1In) external { // ... } } 三、NFT开发 1 2 3 4 5 6 7 8 9 10 11 12 import "@openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol"; contract MyNFT is ERC721URIStorage { uint256 private _tokenIdCounter; function mint(address to, string memory uri) public returns (uint256) { uint256 tokenId = _tokenIdCounter++; _safeMint(to, tokenId); _setTokenURI(tokenId, uri); return tokenId; } } 四、前端集成 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 import { ethers } from 'ethers'; // 连接钱包 async function connectWallet() { const provider = new ethers.BrowserProvider(window.ethereum); await provider.send("eth_requestAccounts", []); const signer = await provider.getSigner(); return signer; } // 调用合约 async function mintNFT(signer, contractAddress, uri) { const contract = new ethers.Contract( contractAddress, ['function mint(address to, string memory uri) returns (uint256)'], signer ); const tx = await contract.mint(await signer.getAddress(), uri); await tx.wait(); } 总结 Web3开发需要掌握智能合约、区块链原理和前端集成。持续关注安全最佳实践至关重要。 ...