TRC-20 合约示例

pragma solidity 0.5.10;

/**
 * @dev 1. TRC20 标准接口
 */
interface ITRC20 {
    /**
     * @dev 返回流通中的Token总量。
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev 返回 `account` 持有的Token数量。
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev 将 `amount` 个Token从调用者账户转移到 `recipient`。
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev 返回 `spender` 仍被允许代表 `owner` 花费的Token剩余数量。
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev 将 `amount` 设置为 `spender` 对调用者Token的授权额度。
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev 通过授权机制将 `amount` 个Token从 `sender` 移动到 `recipient`。
     */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);

    /**
     * @dev 当 `value` 个Token从一个账户（`from`）转移到另一个账户（`to`）时触发。
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev 当 `owner` 为 `spender` 设置授权额度时触发。
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

/**
 * @dev 2. SafeMath 库
 * 对 Solidity 算术运算的封装，增加了溢出检查。
 */
library SafeMath {
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");
        return c;
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SafeMath: subtraction overflow");
        uint256 c = a - b;
        return c;
    }

    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }
        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");
        return c;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: division by zero");
        uint256 c = a / b;
        return c;
    }

    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b != 0, "SafeMath: modulo by zero");
        return a % b;
    }
}

/**
 * @dev 3. {ITRC20} 接口的实现
 */
contract TRC20 is ITRC20 {
    using SafeMath for uint256;

    mapping (address => uint256) private _balances;
    mapping (address => mapping (address => uint256)) private _allowances;

    uint256 private _totalSupply;

    function totalSupply() public view returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(address account) public view returns (uint256) {
        return _balances[account];
    }

    function transfer(address recipient, uint256 amount) public returns (bool) {
        _transfer(msg.sender, recipient, amount);
        return true;
    }

    function allowance(address owner, address spender) public view returns (uint256) {
        return _allowances[owner][spender];
    }

    function approve(address spender, uint256 value) public returns (bool) {
        _approve(msg.sender, spender, value);
        return true;
    }

    function transferFrom(address sender, address recipient, uint256 amount) public returns (bool) {
        _transfer(sender, recipient, amount);
        _approve(sender, msg.sender, _allowances[sender][msg.sender].sub(amount));
        return true;
    }

    function increaseAllowance(address spender, uint256 addedValue) public returns (bool) {
        _approve(msg.sender, spender, _allowances[msg.sender][spender].add(addedValue));
        return true;
    }

    function decreaseAllowance(address spender, uint256 subtractedValue) public returns (bool) {
        _approve(msg.sender, spender, _allowances[msg.sender][spender].sub(subtractedValue));
        return true;
    }

    function _transfer(address sender, address recipient, uint256 amount) internal {
        require(sender != address(0), "TRC20: transfer from the zero address");
        require(recipient != address(0), "TRC20: transfer to the zero address");

        _balances[sender] = _balances[sender].sub(amount);
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
    }

    function _mint(address account, uint256 amount) internal {
        require(account != address(0), "TRC20: mint to the zero address");
        _totalSupply = _totalSupply.add(amount);
        _balances[account] = _balances[account].add(amount);
        emit Transfer(address(0), account, amount);
    }

    function _burn(address account, uint256 value) internal {
        require(account != address(0), "TRC20: burn from the zero address");
        _totalSupply = _totalSupply.sub(value);
        _balances[account] = _balances[account].sub(value);
        emit Transfer(account, address(0), value);
    }

    function _approve(address owner, address spender, uint256 value) internal {
        require(owner != address(0), "TRC20: approve from the zero address");
        require(spender != address(0), "TRC20: approve to the zero address");

        _allowances[owner][spender] = value;
        emit Approval(owner, spender, value);
    }
}

/**
 * @dev 4. TRC20 标准中的可选函数
 */
contract TRC20Detailed is ITRC20 {
    string private _name;
    string private _symbol;
    uint8 private _decimals;

    constructor (string memory name, string memory symbol, uint8 decimals) public {
        _name = name;
        _symbol = symbol;
        _decimals = decimals;
    }

    function name() public view returns (string memory) {
        return _name;
    }

    function symbol() public view returns (string memory) {
        return _symbol;
    }

    function decimals() public view returns (uint8) {
        return _decimals;
    }
}

/**
 * @dev 5. 最终Token业务合约
 */
contract Token is TRC20, TRC20Detailed {
    /**
     * @dev 构造函数：将所有预分配Token分配给创建者。
     * 将 "YourTokenName" 和 "YTN" 替换为你希望的值。
     */
    constructor () public TRC20Detailed("YourTokenName", "YTN", 18) {
        /**
         * @dev 铸造初始供应量。
         * 总供应量 = 10,000,000,000 * 10^18（精度为 18 时）
         */
        _mint(msg.sender, 10000000000 * (10 ** uint256(decimals())));
    }
}