在單個界面中聲明兩個不同智能合約的功能

pragma solidity ^0.7.0;

interface IUniswap {
 function swapExactTokensForETH(
   uint amountIn, 
   uint amountOutMin, 
   address[] calldata path, 
   address to, 
   uint deadline)
   external
   returns (uint[] memory amounts);
 function WETH() external pure returns (address);
}

interface IERC20 {
 function transferFrom(
   address sender, 
   address recipient, 
   uint256 amount) 
   external 
   returns (bool);
}

contract MyDeFiProject {
 IUniswap uniswap;

 constructor(address _uniswap) {
   uniswap = IUniswap(_uniswap);
 }

 function swapTokensForEth(address token, uint amountIn, uint amountOutMin, uint deadline) external {
   IERC20(token).transferFrom(msg.sender, address(this), amountIn);
   address[] memory path = new address[](2);
   path[0] = address(DAI);
   path[1] = uniswap.WETH();
   IERC20(token).approve(address(uniswap), amountIn);
   uniswap.swapExactTokensForETH(
     amountIn, 
     amountOutMin, 
     path, 
     msg.sender, 
     deadline
   );
 }
}

在上面的介面IUniswap中，函式swapExactTokensForETH取自IUniswapV2Router02.sol，而函式WETH取自IUniswapV2Router01.sol。這已在EatTheBlocks的 YouTube 頻道中顯示。這是影片。

我的問題是如何從同一個介面呼叫不同智能合約的兩個不同功能？

這是因為 IUniswapV2Router02.sol 繼承了 IUniswapV2Router01.sol。因此，您可能會認為Router02 介面是Router01 介面的擴展，具有其所有功能。

引用自：https://ethereum.stackexchange.com/questions/110789