ownable.sol库 用于设置拥有者调用的库

pragma solidity ^0.5.12;

/**
 * @title Ownable
 * @dev The Ownable contract has an owner address, and provides basic authorization control
 * functions, this simplifies the implementation of "user permissions".
 */
contract Ownable {
  address payable public owner;

  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

  /**
   * @dev The Ownable constructor sets the original `owner` of the contract to the sender
   * account.
   */
  constructor() public {
    owner = msg.sender;
  }


  /**
   * @dev Throws if called by any account other than the owner.
   */
  modifier onlyOwner() {
    require(msg.sender == owner,'Must contract owner');
    _;
  }


  /**
   * @dev Allows the current owner to transfer control of the contract to a newOwner.
   * @param newOwner The address to transfer ownership to.
   */
  function transferOwnership(address payable newOwner) public onlyOwner {
    require(newOwner != address(0),'Must contract owner');
    emit OwnershipTransferred(owner, newOwner);
    owner = newOwner;
  }

}

下面代码不全 其实核心要调用 ownable.sol 这里就不在赘述

pragma solidity ^0.5.12;

import "./zombieMarket.sol";
import "./zombieFeeding.sol";
import "./zombieAttack.sol";

contract ZombieCore is ZombieMarket,ZombieFeeding,ZombieAttack {
    //constant常量无法修改
    string public constant name = "MyCryptoZombie";
    string public constant symbol = "MCZ";

    //外部转出币要加空函数
    function() external payable {
    }

    //创建者提取全部币
    function withdraw() external onlyOwner {
        owner.transfer(address(this).balance);
    }

    function checkBalance() external view onlyOwner returns(uint) {
        return address(this).balance;
    }
}