终于到发币了，写完这篇关于以太坊的东东基本就结束了，至于开发工具(如truffle等)我就不写了，基于此已经完全可以自己搞条链(或者用以太坊的链)发token，做应用足够了。
ERC20标准
ERC20的Token标准,发行的token都要遵守此标准，在这个标准上进行扩冲即可；标准很简单，这里只对这个标准中的approve、transferFrom及allowance三个函数举个例子解释下：
A有1000个token，允许B账户使用500个。则A调用approve(B,500)。此时B可以调用transferFrom(A, C, 10)给C转10个token。若调用allowance(A, B)则可以查看B还能够调用A多少token。
合约Demo
这个demo不是我写的，有注释，很详细了，转自zhongxh's test token (ZTT)，由于这个合约写的比较早，现在已经跑不起来了，我就把合约中的语法进行了修改，以下是修改后的版本：
pragma solidity ^0.4.18;
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 public 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) public 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) public 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) public 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 public 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);
}
contract StandardToken is Token {
function transfer(address _to, uint256 _value) public 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
emit Transfer(msg.sender, _to, _value);//触发转币交易事件
return true;
}
function transferFrom(address _from, address _to, uint256 _value) public 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
emit Transfer(_from, _to, _value);//触发转币交易事件
return true;
}
function balanceOf(address _owner) constant public returns (uint256 balance) {
return balances[_owner];
}
function approve(address _spender, uint256 _value) public returns (bool success) {
allowed[msg.sender][_spender] = _value;
emit Approval(msg.sender, _spender, _value);
return true;
}
function allowance(address _owner, address _spender) constant public 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;
}
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
constructor(uint256 _initialAmount, string _tokenName, uint8 _decimalUnits, string _tokenSymbol) public {
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
}
/* Approves and then calls the receiving contract */
function approveAndCall(address _spender, uint256 _value, bytes _extraData) public returns (bool success) {
allowed[msg.sender][_spender] = _value;
emit 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(keccak256("receiveApproval(address,uint256,address,bytes)"))), msg.sender, _value, this, _extraData));
return true;
}
}
傻瓜式发币
之所以称之为'傻瓜式'，是因为所有东西都有人帮你做了，你只需要配合着Metamask插件，打开网站，输入Token的数量、名称、小数点位数、符号点击创建即可。
谷歌翻译 For Mac
另外因为喜欢使用谷歌翻译，又懒的每次去打开浏览器，就把网页版的做成应用，放到Dock上方便使用，需要的小伙伴可自行下载Mac版谷歌翻译,欢迎点赞。
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