Web3DeFiSolidity

DeFi 智能合约开发入门：从 Swap 到 Lending

EasyGo2025-11-0520 分钟

DeFi 核心概念

**AMM**: 自动做市商

**流动性池**: 提供交易对手方

**闪电贷**: 无抵押借贷

**收益耕作**: 流动性挖矿

简单 Swap 实现

solidity

1// SPDX-License-Identifier: MIT
2pragma solidity ^0.8.0;
3
4contract SimpleSwap {
5    mapping(address => uint256) public reserves;
6    
7    function swap(address tokenIn, address tokenOut, uint256 amountIn) 
8        external 
9        returns (uint256 amountOut) 
10    {
11        uint256 reserveIn = reserves[tokenIn];
12        uint256 reserveOut = reserves[tokenOut];
13        
14        // x * y = k
15        amountOut = (amountIn * reserveOut) / (reserveIn + amountIn);
16        
17        // 更新储备
18        reserves[tokenIn] += amountIn;
19        reserves[tokenOut] -= amountOut;
20    }
21}

总结

DeFi 协议的核心是用智能合约实现金融逻辑，理解底层原理对于开发和审计都至关重要。