威海市建设局官方网站,设计图案,赣州网站建设中心,深圳搭建网站公司文章目录 IERC20ERC20 IERC20 IERC20 是 ERC20 标准的接口规范,它定义和规范了一个标准 ERC20 代币合约应该实现的功能。这里让 ERC20 合约直接继承自 IERC20 接口。 // SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;interface IERC20 { // 当 value 单位的货币从账户… 文章目录 IERC20ERC20 IERC20 IERC20 是 ERC20 标准的接口规范,它定义和规范了一个标准 ERC20 代币合约应该实现的功能。这里让 ERC20 合约直接继承自 IERC20 接口。 // SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;interface IERC20 { // 当 value 单位的货币从账户 (from) 转账到另一账户 (to)时 触发event Transfer(address indexed from, address indexed to, uint256 value);// 当 value 单位的货币从账户 (owner) 授权给另一账户 (spender)时触发 event Approval(address indexed owner, address indexed spender, uint256 value);// 返回代币总供给.function totalSupply() external view returns (uint256);// 返回账户account所持有的代币数.function balanceOf(address account) external view returns (uint256);// 转账 amount 单位代币从调用者账户到另一账户 to.function transfer(address to, uint256 amount) external returns (bool);// 返回owner账户授权给spender账户的额度默认为0。function allowances(address owner, address spender) external view returns (uint256);// 调用者账户给spender账户授权 amount数量代币。 function approve(address spender, uint256 amount) external returns (bool);// 通过授权机制从from账户向to账户转账amount数量代币。转账的部分会从调用者的allowances中扣除。function transferFrom( address from, address to, uint256 amount ) external returns (bool);
}ERC20 ERC20 是以太坊上最常见和最流行的代币标准之一, 它定义了一套规则和接口,使得不同的代币可以在同一个平台上互相交换和使用是实现同质化代币的常见选择。ERC20 实现了账户余额、转账、授权、授权转账以及总供给量的代币转账功能。 // SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;import ./IERC20.sol; contract MyToken is IERC20 {mapping(address uint256) public override balanceOf;mapping(address mapping(address uint256)) public override allowances;uint256 public totalSupply; // 代币总供给string public name; // 代币名称string public symbol; // 代币代号uint8 public decimals 18; // 小数位数// 构造函数 constructor(string memory name_, string memory symbol_) {name name_;symbol symbol_;}// 转账function transfer(address recipient, uint256 amount) public override returns (bool) {_transfer(msg.sender, recipient, amount);return true;}// 授权转账 function transferFrom(address sender, address recipient, uint amount) external override returns (bool){_transfer(sender, recipient, amount); uint256 currentAllowance allowances[sender][msg.sender]; require(currentAllowance amount, ERC20: transfer amount exceeds allowances); // 是否超过授权额度 _approve(sender, msg.sender, currentAllowance - amount);return true;} function _transfer(address sender, address recipient, uint256 amount) internal {require(sender ! address(0), ERC20: transfer from the zero address);require(recipient ! address(0), ERC20: transfer to the zero address);uint256 senderBalance balanceOf[sender];require(senderBalance amount, ERC20: transfer amount exceeds balance);balanceOf[sender] senderBalance - amount;balanceOf[recipient] amount;emit Transfer(sender, recipient, amount);}// 授权 function approve(address spender, uint amount) external override returns (bool){_approve(msg.sender, spender, amount); return true;}function _approve(address owner, address spender, uint256 amount) internal {require(owner ! address(0), ERC20: approve from the zero address); // 授权无效地址 require(spender ! address(0), ERC20: approve to the zero address);allowances[owner][spender] amount;emit Approval(owner, spender, amount);}// 锻造代币function mint(address account, uint amount) external {require(account ! address(0), ERC20: mint to the zero address);balanceOf[account] amount; totalSupply amount;emit Transfer(address(0), msg.sender, amount);}// 销毁代币 function burn(address account, uint amount) external {require(account ! address(0), ERC20: burn from the zero address);uint256 accountBalance balanceOf[account]; require(accountBalance amount, ERC20: burn amount exceeds balance);balanceOf[account] accountBalance - amount;totalSupply - amount; emit Transfer(account, address(0), amount); }
}
