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使用 Remix 和 MetaMask 发行以太坊 ERC20 Token

苹果手机怎么下载imtoken 2023-01-17 13:21:47

ERC20是在以太坊网络上发行代币（Token）的标准协议接口。协议的具体描述位于github上。标准协议使令牌能够用于不同的应用程序，例如钱包和去中心化交易所。目前有很多实现标准协议的Token Example，我们将使用提供的例子来演示操作。我们先看看这个实现库中的主要合约文件：

ERC20 Token协议实现了Token.sol ERC 20协议的抽象定义

//Abstract contract for the full ERC 20 Token standard
// https://github.com/ethereum/EIPs/issues/20
pragma solidity ^0.4.8;
contract Token {
    /// token总量，默认会为public变量生成一个getter函数接口，名称为totalSupply().
    uint256 public totalSupply;
    /// 获取账户_owner拥有token的数量
    function balanceOf(address _owner) constant returns (uint256 balance);
    //从消息发送者账户中往_to账户转数量为_value的token
    function transfer(address _to, uint256 _value) returns (bool success);
    //从账户_from中往账户_to转数量为_value的token，与approve方法配合使用
    function transferFrom(address _from, address _to, uint256 _value) returns  (bool success);
    //消息发送账户设置账户_spender能从发送账户中转出数量为_value的token
    function approve(address _spender, uint256 _value) returns (bool success);
    //获取账户_spender可以从账户_owner中转出token的数量
    function allowance(address _owner, address _spender) constant returns  (uint256 remaining);
    //发生转账时必须要触发的事件 
    event Transfer(address indexed _from, address indexed _to, uint256 _value);
    //当函数approve(address _spender, uint256 _value)成功执行时必须触发的事件
    event Approval(address indexed _owner, address indexed _spender, uint256 _value);
}

StandardToken.sol ERC20 协议的标准实现

You should inherit from StandardToken or, for a token like you would want to
deploy in something like Mist, see HumanStandardToken.sol.
(This implements ONLY the standard functions and NOTHING else.
If you deploy this, you won't have anything useful.)
Implements ERC 20 Token standard: https://github.com/ethereum/EIPs/issues/20.*/
pragma solidity ^0.4.8;
import "./Token.sol";
contract StandardToken is Token {
    function transfer(address _to, uint256 _value) returns (bool success) {
        //默认totalSupply 不会超过最大值 (2^256 - 1).
        //如果随着时间的推移将会有新的token生成，则可以用下面这句避免溢出的异常
        //require(balances[msg.sender] >= _value && balances[_to] + _value >balances[_to]);
        require(balances[msg.sender] >= _value);
        balances[msg.sender] -= _value;//从消息发送者账户中减去token数量_value
        balances[_to] += _value;//往接收账户增加token数量_value
        Transfer(msg.sender, _to, _value);//触发转币交易事件
        return true;
    }
    function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {
        //require(balances[_from] >= _value && allowed[_from][msg.sender] >= _value && balances[_to] + _value > balances[_to]);
        require(balances[_from] >= _value && allowed[_from][msg.sender] >=  _value);
        balances[_to] += _value;//接收账户增加token数量_value
        balances[_from] -= _value; ;//支出账户_from减去token数量_value
        allowed[_from][msg.sender] -= _value;//消息发送者可以从账户_from中转出的数量减少_value
        Transfer(_from, _to, _value);//触发转币交易事件
        return true;
    }
    //查询余额
    function balanceOf(address _owner) constant returns (uint256 balance) {
        return balances[_owner];
    }
    //授权账户_spender可以从消息发送者账户转出数量为_value的token
    function approve(address _spender, uint256 _value) returns (bool success)   
    {
        allowed[msg.sender][_spender] = _value;
        Approval(msg.sender, _spender, _value);
        return true;
    }
    function allowance(address _owner, address _spender) constant returns (uint256 remaining) {
      return allowed[_owner][_spender];//允许_spender从_owner中转出的token数
    }
    mapping (address => uint256) balances;
    mapping (address => mapping (address => uint256)) allowed;
}

HumanStandardToken.sol 特定令牌实现

This Token Contract implements the standard token functionality (https://github.com/ethereum/EIPs/issues/20) as well as the following OPTIONAL extras intended for use by humans.
In other words. This is intended for deployment in something like a Token Factory or Mist wallet, and then used by humans.
Imagine coins, currencies, shares, voting weight, etc.
Machine-based, rapid creation of many tokens would not necessarily need these extra features or will be minted in other manners.
1) Initial Finite Supply (upon creation one specifies how much is minted).
2) In the absence of a token registry: Optional Decimal, Symbol & Name.
3) Optional approveAndCall() functionality to notify a contract if an approval() has occurred.
.*/
import "./StandardToken.sol";
pragma solidity ^0.4.8;
contract HumanStandardToken is StandardToken {
    /* Public variables of the token */
    string public name;                   //名称: eg Simon Bucks
    uint8 public decimals;                //最多的小数位数How many decimals to show. ie. There could 1000 base units with 3 decimals. Meaning 0.980 SBX = 980 base units. It's like comparing 1 wei to 1 ether.
    string public symbol;                 //token简称: eg SBX
    string public version = 'H0.1';       //版本
    function HumanStandardToken(uint256 _initialAmount, string _tokenName, uint8 _decimalUnits, string _tokenSymbol) {
        balances[msg.sender] = _initialAmount; // 初始token数量给予消息发送者
        totalSupply = _initialAmount;         // 设置初始总量
        name = _tokenName;                   // token名称
        decimals = _decimalUnits;           // 小数位数
        symbol = _tokenSymbol;             // token简称
    }
    /* 同意转出并调用接收合约（根据自己需求实现） */
    function approveAndCall(address _spender, uint256 _value, bytes _extraData) returns (bool success) {
        allowed[msg.sender][_spender] = _value;
        Approval(msg.sender, _spender, _value);
        //call the receiveApproval function on the contract you want to be notified. This crafts the function signature manually so one doesn't have to include a contract in here just for this.
        //receiveApproval(address _from, uint256 _value, address _tokenContract, bytes _extraData)
        //it is assumed that when does this that the call *should* succeed, otherwise one would use vanilla approve instead.
        
        require(_spender.call(bytes4(bytes32(sha3("receiveApproval(address,uint256,address,bytes)"))), msg.sender, _value, this, _extraData));
        return true;
    }
}

代币合约发布

我们将使用 MetaMask（chrome 插件安装链接）和 Remix() 并选择在 Ropsten 测试网络上发布 Token 合约（获得免费的 ETH：）。

将 MetaMask 切换到 Ropsten 网络