通过一个案例精通以太坊智能合约和Solidity

作者介绍

Silver CEO 星际区块链信息发展有限公司

项目组件

  这个项目是一个构建在以太坊上的游戏，感谢这个团队给我们提供的案例：https://cryptozombies.io

  从功能的角度看，有如下脚本：

• zombiefactory.sol:定义zombie和生成zombie。
• zombiefeeding.sol:定义小猫接口，给zombie吃小猫。
• zombieattack.sol:zombie打架的功能。
• erc721.sol:ERC721代币的接口。
• ownable.sol:用户认证的接口。
• safemath.sol:运算时安全检查。
• zombieownership.sol：zombie的所属功能，transfer，approve，takeOwnership等功能。
• zombiehelper.sol:zombie的辅助功能。该名字，改DNA，提升等级，设置levelUpFee，提现，查看僵尸军团等功能。
• index.html:前端交互调用。
• cryptozombies_abi.js:ABI文档。

zombiefactory.sol

pragma solidity ^0.4.19;

import "./ownable.sol";
import "./safemath.sol";

contract ZombieFactory is Ownable {

  using SafeMath for uint256;

  // 事件是合约和区块链通讯的一种机制。
  // 当僵尸创造出来时，前端能监听到这个事件，并将它显示出来。
  event NewZombie(uint zombieId, string name, uint dna);

  /**
    僵尸的NDA只有16个字符
    dnaModulus等于10^16,DNA可以用模运算符 % 把一个整数变成16位
    冷却时间长达1天
  **/
  uint dnaDigits = 16;
  uint dnaModulus = 10 ** dnaDigits;
  uint cooldownTime = 1 days;

  // 使用struct节省存储空间，节约gas。readyTime实现“冷却定时器”
  struct Zombie {
    string name;
    uint dna;
    uint32 level;
    uint32 readyTime;
    uint16 winCount;
    uint16 lossCount;
  }

  // 公共可变长数组
  Zombie[] public zombies;

  // 给数据库中的僵尸指定主人，支持多玩家模式
  // mapping和address，通过僵尸id查到拥有者的address
  mapping (uint => address) public zombieToOwner;
  // 通过address查询到有多少只僵尸
  mapping (address => uint) ownerZombieCount;

  // 内部方法以 _ 开头，函数里面的变量以 _ 开头，区别全局变量。
  function _createZombie(string _name, uint _dna) internal {
    uint id = zombies.push(Zombie(_name, _dna, 1, uint32(now + cooldownTime), 0, 0)) - 1;
    // msg.sender 是合约当前调用者的address或者智能合约的address
    zombieToOwner[id] = msg.sender;
    ownerZombieCount[msg.sender]++;
    NewZombie(id, _name, _dna);
  }

  // 函数没有改变Solidity里的状态，没有改变任何值或者写任何东西，把函数定义为view，
  // 意味着只能读取数据不能更改数据
  // keccak256是以太坊提供的SHA3散列函数，把一个字符串转换成一个256位的16进制数字。
  // 只能用它造一个伪随机数。
  function _generateRandomDna(string _str) private view returns (uint) {
    uint rand = uint(keccak256(_str));
    return rand % dnaModulus;
  }

  function createRandomZombie(string _name) public {
    // require使函数在执行过程中，当不满足某些条件时抛出错误，并停止执行
    require(ownerZombieCount[msg.sender] == 0);
    uint randDna = _generateRandomDna(_name);
    randDna = randDna - randDna % 100;
    _createZombie(_name, randDna);
  }

}

zombiefeeding.sol

pragma solidity ^0.4.19;

import "./zombiefactory.sol";

// 定义一个借口，使用contract关键字，在接口里定义getKitty函数
contract KittyInterface {
  function getKitty(uint256 _id) external view returns (
    bool isGestating,
    bool isReady,
    uint256 cooldownIndex,
    uint256 nextActionAt,
    uint256 siringWithId,
    uint256 birthTime,
    uint256 matronId,
    uint256 sireId,
    uint256 generation,
    uint256 genes
  );
}

// 继承ZombieFactory合约
contract ZombieFeeding is ZombieFactory {

  KittyInterface kittyContract;

  // modifier关键字告诉编译器，这是个modifier修饰符，而不是function，不能像函数直接调用，只能添加到函数定义的末尾，用以改变函数的行为
  modifier onlyOwnerOf(uint _zombieId) {
    require(msg.sender == zombieToOwner[_zombieId]);
    _;
  }

  // external 函数只能在合约之外调用，不能被合约内的其他函数调用
  // 通过程序更改CryptoKities合约地址
  // onlyOwner是指定合约的所有权，指定一个主人，只有主人（合约部署者）对它享有特权
  function setKittyContractAddress(address _address) external onlyOwner {
    kittyContract = KittyInterface(_address);
  }

  // internal 合约可访问父合约中定义的内部函数
  function _triggerCooldown(Zombie storage _zombie) internal {
    _zombie.readyTime = uint32(now + cooldownTime);
  }

  function _isReady(Zombie storage _zombie) internal view returns (bool) {
      return (_zombie.readyTime <= now);
  }

  function feedAndMultiply(uint _zombieId, uint _targetDna, string _species) internal onlyOwnerOf(_zombieId) {
    // storage变量永久存储在区块链中
    Zombie storage myZombie = zombies[_zombieId];
    require(_isReady(myZombie));
    _targetDna = _targetDna % dnaModulus;
    uint newDna = (myZombie.dna + _targetDna) / 2;
    // 如果是kitty变过来的，用99替换新僵尸DNA的最后两位数字
    if (keccak256(_species) == keccak256("kitty")) {
      newDna = newDna - newDna % 100 + 99;
    }
    _createZombie("NoName", newDna);
    _triggerCooldown(myZombie);
  }

  function feedOnKitty(uint _zombieId, uint _kittyId) public {
    uint kittyDna;
    (,,,,,,,,,kittyDna) = kittyContract.getKitty(_kittyId);
    feedAndMultiply(_zombieId, kittyDna, "kitty");
  }
}

zombieattack.sol

pragma solidity ^0.4.19;

import "./zombiehelper.sol";

/**
  僵尸战斗功能，继承自ZombieHelper
**/
contract ZombieAttack is ZombieHelper {
  uint randNonce = 0;
  uint attackVictoryProbability = 70;

  // 拿now，msg.sender,自增的nonce，转成一个哈希值，再转uint，% 100 取最后两位，生成一个0到100的随机数
  // 当然最后拿到的是一个伪随机数，但在具体的项目中，不会吸引×××者来×××就是现实安全的。
  function randMod(uint _modulus) internal returns(uint) {
    randNonce++;
    return uint(keccak256(now, msg.sender, randNonce)) % _modulus;
  }

  // 选择自己的僵尸，选择对手的一个僵尸去×××
  // ×××方有70%的获胜概率
  // 所有的僵尸都有一个winCount和lossCount，记录输赢
  // ×××方获胜，僵尸升级并产生一个新僵尸，成功次数累加1
  // ×××方失败，失败次数累加1
  // 无论输赢，当前僵尸的冷却时间将被激活
  function attack(uint _zombieId, uint _targetId) external onlyOwnerOf(_zombieId) {
    Zombie storage myZombie = zombies[_zombieId];
    Zombie storage enemyZombie = zombies[_targetId];
    uint rand = randMod(100);
    if (rand <= attackVictoryProbability) {
      myZombie.winCount++;
      myZombie.level++;
      enemyZombie.lossCount++;
      feedAndMultiply(_zombieId, enemyZombie.dna, "zombie");
    } else {
      myZombie.lossCount++;
      enemyZombie.winCount++;
      _triggerCooldown(myZombie);
    }
  }
}

erc721.sol

/**
  ERC20代币，一个代币只是一个追踪谁拥有多少该代币的合约，和一些可以让那些用户将它们的代币转移到其他地址的函数

  ERC721 适合CryptpZombies这样的加密收藏品，是ERC721代币
  ERC721代币是不能互换的，因为每个代币都被认为是唯一且不可分割的。只能以整个单位交易它们。

  搞出一个ERC721的标准，好处显而易见：我们不必在合约中实现拍卖和托管逻辑，符合其规范，其他人可以为
  加密可交易的ERC721资产搭建交易平台，ERC721僵尸也可在上面使用和交易。
**/
contract ERC721 {
  event Transfer(address indexed _from, address indexed _to, uint256 _tokenId);
  event Approval(address indexed _owner, address indexed _approved, uint256 _tokenId);

  function balanceOf(address _owner) public view returns (uint256 _balance);
  function ownerOf(uint256 _tokenId) public view returns (address _owner);
  function transfer(address _to, uint256 _tokenId) public;
  function approve(address _to, uint256 _tokenId) public;
  function takeOwnership(uint256 _tokenId) public;
}

ownable.sol

pragma solidity ^0.4.19;
/**
 * @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 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.
   */
  function Ownable() public {
    owner = msg.sender;
  }

  /**
   * @dev Throws if called by any account other than the owner.
   */
  modifier onlyOwner() {
    require(msg.sender == 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 newOwner) public onlyOwner {
    require(newOwner != address(0));
    OwnershipTransferred(owner, newOwner);
    owner = newOwner;
  }

}

safemath.sol

pragma solidity ^0.4.18;

/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 */
library SafeMath {

  /**
  * @dev Multiplies two numbers, throws on overflow.
  */
  function mul(uint256 a, uint256 b) internal pure returns (uint256) {
    if (a == 0) {
      return 0;
    }
    uint256 c = a * b;
    assert(c / a == b);
    return c;
  }

  /**
  * @dev Integer division of two numbers, truncating the quotient.
  */
  function div(uint256 a, uint256 b) internal pure returns (uint256) {
    // assert(b > 0); // Solidity automatically throws when dividing by 0
    uint256 c = a / b;
    // assert(a == b * c + a % b); // There is no case in which this doesn't hold
    return c;
  }

  /**
  * @dev Subtracts two numbers, throws on overflow (i.e. if subtrahend is greater than minuend).
  */
  function sub(uint256 a, uint256 b) internal pure returns (uint256) {
    assert(b <= a);
    return a - b;
  }

  /**
  * @dev Adds two numbers, throws on overflow.
  */
  function add(uint256 a, uint256 b) internal pure returns (uint256) {
    uint256 c = a + b;
    assert(c >= a);
    return c;
  }
}

zombieownership.sol

pragma solidity ^0.4.19;

import "./zombieattack.sol";
import "./erc721.sol";
import "./safemath.sol";

contract ZombieOwnership is ZombieAttack, ERC721 {

  using SafeMath for uint256;

  mapping (uint => address) zombieApprovals;

  // 传入address函数，返回address拥有多少ERC721代币，整数不可分割
  function balanceOf(address _owner) public view returns (uint256 _balance) {
    return ownerZombieCount[_owner];
  }

  // 传入一个代币ID，也是僵尸ID，返回该代币拥有者的address
  function ownerOf(uint256 _tokenId) public view returns (address _owner) {
    return zombieToOwner[_tokenId];
  }

  // 代币的拥有者调用transfer方法，传入需要转移到的address和他想转移的代币的_tokenId。
  // 合约安全增强：溢出和下溢
  // 溢出（overflow），uint8的变量，存储的最大数就是二进制11111111，也就是十进制的255，加1就出现溢出。
  // 下溢（underflow），一个等于0的uint8，减去1就出现下溢，变成255，uint是无符号的，不能等于复数。
  function _transfer(address _from, address _to, uint256 _tokenId) private {
    ownerZombieCount[_to] = ownerZombieCount[_to].add(1);
    ownerZombieCount[msg.sender] = ownerZombieCount[msg.sender].sub(1);
    zombieToOwner[_tokenId] = _to;
    Transfer(_from, _to, _tokenId);
  }

  // 都有一个修饰符onlyOwnerOf
  function transfer(address _to, uint256 _tokenId) public onlyOwnerOf(_tokenId) {
    _transfer(msg.sender, _to, _tokenId);
  }

  // 代币的拥有者调用approve，传入允许提取代币的address和允许提取的代币_tokenId。
  function approve(address _to, uint256 _tokenId) public onlyOwnerOf(_tokenId) {
    zombieApprovals[_tokenId] = _to;
    Approval(msg.sender, _to, _tokenId);
  }

  // require检查确保msg.sender已经被批准来提取这个代币，也就是僵尸。
  function takeOwnership(uint256 _tokenId) public {
    require(zombieApprovals[_tokenId] == msg.sender);
    address owner = ownerOf(_tokenId);
    _transfer(owner, msg.sender, _tokenId);
  }
}

zombiehelper.sol

pragma solidity ^0.4.19;

import "./zombiefeeding.sol";

/**
  辅助方法
**/
contract ZombieHelper is ZombieFeeding {

  uint levelUpFee = 0.001 ether;

  // 修饰符modifier的最后一行为 _ ，表示修饰符调用结束后返回，并执行调用函数余下的部分。
  modifier aboveLevel(uint _level, uint _zombieId) {
    require(zombies[_zombieId].level >= _level);
    _;
  }

  // 提现功能，只能是合约主人享有
  // 通过transfer函数向一个地址发送以太
  function withdraw() external onlyOwner {
    owner.transfer(this.balance);
  }

  // 合约主人设置levelUpFee
  function setLevelUpFee(uint _fee) external onlyOwner {
    levelUpFee = _fee;
  }

  // payable修饰符，是一种可以接收以太的特殊函数
  // 通过支付ETH来升级僵尸，ETH将存储在你拥有的合约中
  function levelUp(uint _zombieId) external payable {
    require(msg.value == levelUpFee);
    zombies[_zombieId].level++;
  }

  // 2级以上的僵尸可以改名
  function changeName(uint _zombieId, string _newName) external aboveLevel(2, _zombieId) onlyOwnerOf(_zombieId) {
    zombies[_zombieId].name = _newName;
  }

  // 20级以上的僵尸可以定制DNA
  function changeDna(uint _zombieId, uint _newDna) external aboveLevel(20, _zombieId) onlyOwnerOf(_zombieId) {
    zombies[_zombieId].dna = _newDna;
  }

  // 查看某个某家的整个僵尸军团，只需要从区块链中读取数据，view函数。
  function getZombiesByOwner(address _owner) external view returns(uint[]) {
    // memory 关键字是使用临时存储，调用完就释放
    uint[] memory result = new uint[](ownerZombieCount[_owner]);
    uint counter = 0;
    for (uint i = 0; i < zombies.length; i++) {
      if (zombieToOwner[i] == _owner) {
        result[counter] = i;
        counter++;
      }
    }
    return result;
  }

}

index.html

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8">
    <title>CryptoZombies front-end</title>
    <script language="javascript" type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
    <script language="javascript" type="text/javascript" src="web3.min.js"></script>
    <script language="javascript" type="text/javascript" src="cryptozombies_abi.js"></script>
  </head>
  <body>
    <div id="txStatus"></div>
    <div id="zombies"></div>

    <script>
      var cryptoZombies;
      var userAccount;

      // Web3.js需要合约地址和ABI来和合约进行对话
      // 编译了ABI放在cryptozobimes_abi.js文件中，保存为一个名为cryptoZombiesABI的变量中
      // Web3.js有两个方法来调用合约的函数：call和send
      // call用来调用view和pure函数，只运行在本地节点，不会在区块链上创建事务
      // send将创建一个事务并改变区块链上的数据，用send调用非view和pure的函数
      function startApp() {
        var cryptoZombiesAddress = "YOUR_CONTRACT_ADDRESS";
        cryptoZombies = new web3js.eth.Contract(cryptoZombiesABI, cryptoZombiesAddress);

        // 在MetaMask中切换账户，应用需要监控这个变量，通过setInterval方法来实现
        var accountInterval = setInterval(function() {
          // Check if account has changed
          if (web3.eth.accounts[0] !== userAccount) {
            userAccount = web3.eth.accounts[0];
            // Call a function to update the UI with the new account
            getZombiesByOwner(userAccount)
            .then(displayZombies);
          }
        }, 100);

        // Web3 provider说明跟哪个节点进行交互处理我们的读写。
        // Infura是一个服务，维护了大量以太坊节点并提供一个缓存层来实现高速读取。
        var web3Infura = new Web3(new Web3.providers.WebsocketProvider("wss://mainnet.infura.io/ws"));
        var czEvents = new web3Infura.eth.Contract(cryptoZombiesABI, cryptoZombiesAddress);

        // 任何僵尸生成的时候激发一个警告信息，
        // 如果只想监听对当前用户的提醒呢，使用indexed关键字
        // 例如 event Transfer(address indexed _from, address indexed _to, uint256 _tokenId);
        // _from 和 _to 都是indexed，可在前端事件监听中过滤事件
        czEvents.events.Transfer({ filter: { _to: userAccount } })
        .on("data", function(event) {
          let data = event.returnValues;
          getZombiesByOwner(userAccount).then(displayZombies);
        }).on('error', console.error);
      }

      function displayZombies(ids) {
        $("#zombies").empty();
        for (id of ids) {
          // Look up zombie details from our contract. Returns a `zombie` object
          getZombieDetails(id)
          .then(function(zombie) {
            // Using ES6's "template literals" to inject variables into the HTML.
            // Append each one to our #zombies div
            $("#zombies").append(`<div class="zombie">
              <ul>
                <li>Name: ${zombie.name}</li>
                <li>DNA: ${zombie.dna}</li>
                <li>Level: ${zombie.level}</li>
                <li>Wins: ${zombie.winCount}</li>
                <li>Losses: ${zombie.lossCount}</li>
                <li>Ready Time: ${zombie.readyTime}</li>
              </ul>
            </div>`);
          });
        }
      }

      function createRandomZombie(name) {
        // This is going to take a while, so update the UI to let the user know
        // the transaction has been sent
        $("#txStatus").text("Creating new zombie on the blockchain. This may take a while...");
        // Send the tx to our contract:
        return cryptoZombies.methods.createRandomZombie(name)
        .send({ from: userAccount })
        .on("receipt", function(receipt) {
          $("#txStatus").text("Successfully created " + name + "!");
          // Transaction was accepted into the blockchain, let's redraw the UI
          getZombiesByOwner(userAccount).then(displayZombies);
        })
        .on("error", function(error) {
          // Do something to alert the user their transaction has failed
          $("#txStatus").text(error);
        });
      }

      function feedOnKitty(zombieId, kittyId) {
        $("#txStatus").text("Eating a kitty. This may take a while...");
        return cryptoZombies.methods.feedOnKitty(zombieId, kittyId)
        .send({ from: userAccount })
        .on("receipt", function(receipt) {
          $("#txStatus").text("Ate a kitty and spawned a new Zombie!");
          getZombiesByOwner(userAccount).then(displayZombies);
        })
        .on("error", function(error) {
          $("#txStatus").text(error);
        });
      }

      function levelUp(zombieId) {
        $("#txStatus").text("Leveling up your zombie...");
        return cryptoZombies.methods.levelUp(zombieId)
        .send({ from: userAccount, value: web3.utils.toWei("0.001", "ether") })
        .on("receipt", function(receipt) {
          $("#txStatus").text("Power overwhelming! Zombie successfully leveled up");
        })
        .on("error", function(error) {
          $("#txStatus").text(error);
        });
      }

      function getZombieDetails(id) {
        return cryptoZombies.methods.zombies(id).call()
      }

      function zombieToOwner(id) {
        return cryptoZombies.methods.zombieToOwner(id).call()
      }

      function getZombiesByOwner(owner) {
        return cryptoZombies.methods.getZombiesByOwner(owner).call()
      }

      window.addEventListener('load', function() {

        // Checking if Web3 has been injected by the browser (Mist/MetaMask)
        if (typeof web3 !== 'undefined') {
          // Use Mist/MetaMask's provider
          web3js = new Web3(web3.currentProvider);
        } else {
          // Handle the case where the user doesn't have Metamask installed
          // Probably show them a message prompting them to install Metamask
        }

        // Now you can start your app & access web3 freely:
        startApp()

      })
    </script>
  </body>
</html>

cryptozombies_abi.js

var cryptozombiesABI = [
  {
    "constant": false,
    "inputs": [
      {
        "name": "_to",
        "type": "address"
      },
      {
        "name": "_tokenId",
        "type": "uint256"
      }
    ],
    "name": "approve",
    "outputs": [],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [
      {
        "name": "_zombieId",
        "type": "uint256"
      }
    ],
    "name": "levelUp",
    "outputs": [],
    "payable": true,
    "stateMutability": "payable",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [
      {
        "name": "_zombieId",
        "type": "uint256"
      },
      {
        "name": "_kittyId",
        "type": "uint256"
      }
    ],
    "name": "feedOnKitty",
    "outputs": [],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "constant": true,
    "inputs": [
      {
        "name": "",
        "type": "uint256"
      }
    ],
    "name": "zombies",
    "outputs": [
      {
        "name": "name",
        "type": "string"
      },
      {
        "name": "dna",
        "type": "uint256"
      },
      {
        "name": "level",
        "type": "uint32"
      },
      {
        "name": "readyTime",
        "type": "uint32"
      },
      {
        "name": "winCount",
        "type": "uint16"
      },
      {
        "name": "lossCount",
        "type": "uint16"
      }
    ],
    "payable": false,
    "stateMutability": "view",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [],
    "name": "withdraw",
    "outputs": [],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "constant": true,
    "inputs": [
      {
        "name": "_owner",
        "type": "address"
      }
    ],
    "name": "getZombiesByOwner",
    "outputs": [
      {
        "name": "",
        "type": "uint256[]"
      }
    ],
    "payable": false,
    "stateMutability": "view",
    "type": "function"
  },
  {
    "constant": true,
    "inputs": [
      {
        "name": "",
        "type": "uint256"
      }
    ],
    "name": "zombieToOwner",
    "outputs": [
      {
        "name": "",
        "type": "address"
      }
    ],
    "payable": false,
    "stateMutability": "view",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [
      {
        "name": "_address",
        "type": "address"
      }
    ],
    "name": "setKittyContractAddress",
    "outputs": [],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [
      {
        "name": "_zombieId",
        "type": "uint256"
      },
      {
        "name": "_newDna",
        "type": "uint256"
      }
    ],
    "name": "changeDna",
    "outputs": [],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "constant": true,
    "inputs": [
      {
        "name": "_tokenId",
        "type": "uint256"
      }
    ],
    "name": "ownerOf",
    "outputs": [
      {
        "name": "_owner",
        "type": "address"
      }
    ],
    "payable": false,
    "stateMutability": "view",
    "type": "function"
  },
  {
    "constant": true,
    "inputs": [
      {
        "name": "_owner",
        "type": "address"
      }
    ],
    "name": "balanceOf",
    "outputs": [
      {
        "name": "_balance",
        "type": "uint256"
      }
    ],
    "payable": false,
    "stateMutability": "view",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [
      {
        "name": "_name",
        "type": "string"
      }
    ],
    "name": "createRandomZombie",
    "outputs": [],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "constant": true,
    "inputs": [],
    "name": "owner",
    "outputs": [
      {
        "name": "",
        "type": "address"
      }
    ],
    "payable": false,
    "stateMutability": "view",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [
      {
        "name": "_to",
        "type": "address"
      },
      {
        "name": "_tokenId",
        "type": "uint256"
      }
    ],
    "name": "transfer",
    "outputs": [],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "constant": true,
    "inputs": [],
    "name": "getAllZombies",
    "outputs": [
      {
        "name": "",
        "type": "uint256[]"
      }
    ],
    "payable": false,
    "stateMutability": "view",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [
      {
        "name": "_tokenId",
        "type": "uint256"
      }
    ],
    "name": "takeOwnership",
    "outputs": [],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [
      {
        "name": "_zombieId",
        "type": "uint256"
      },
      {
        "name": "_newName",
        "type": "string"
      }
    ],
    "name": "changeName",
    "outputs": [],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [
      {
        "name": "_fee",
        "type": "uint256"
      }
    ],
    "name": "setLevelUpFee",
    "outputs": [],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [
      {
        "name": "_zombieId",
        "type": "uint256"
      },
      {
        "name": "_targetId",
        "type": "uint256"
      }
    ],
    "name": "attack",
    "outputs": [],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "constant": false,
    "inputs": [
      {
        "name": "newOwner",
        "type": "address"
      }
    ],
    "name": "transferOwnership",
    "outputs": [],
    "payable": false,
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": true,
        "name": "_from",
        "type": "address"
      },
      {
        "indexed": true,
        "name": "_to",
        "type": "address"
      },
      {
        "indexed": false,
        "name": "_tokenId",
        "type": "uint256"
      }
    ],
    "name": "Transfer",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": true,
        "name": "_owner",
        "type": "address"
      },
      {
        "indexed": true,
        "name": "_approved",
        "type": "address"
      },
      {
        "indexed": false,
        "name": "_tokenId",
        "type": "uint256"
      }
    ],
    "name": "Approval",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": false,
        "name": "attackResult",
        "type": "bool"
      },
      {
        "indexed": false,
        "name": "winCount",
        "type": "uint16"
      },
      {
        "indexed": false,
        "name": "lossCount",
        "type": "uint16"
      }
    ],
    "name": "AttackResult",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": false,
        "name": "zombieId",
        "type": "uint256"
      },
      {
        "indexed": false,
        "name": "name",
        "type": "string"
      },
      {
        "indexed": false,
        "name": "dna",
        "type": "uint256"
      }
    ],
    "name": "NewZombie",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": true,
        "name": "previousOwner",
        "type": "address"
      },
      {
        "indexed": true,
        "name": "newOwner",
        "type": "address"
      }
    ],
    "name": "OwnershipTransferred",
    "type": "event"
  }
]      

文章来源：虫洞社区（https://www.uzanapp.com/ ）