简单记录下这三种ERC协议的要点。源码是openzepplin的实现。ERC20IErc20 接口定义的方法共有以下几个：function totalSupply() external view returns (uint256); function balanceOf(address account) external view returns (uint256); function transfer(address recipient, uint256 amount) external returns (bool); function allowance(address owner, address spender) external view returns (uint256); function approve(address spender, uint256 amount) external returns (bool); function transferFrom(address sender, address recipient, uint256 amount) e...