solidity合约实战(一) 简易ERC20代币开发与发行
环境
开发工具
remix，metamask
代币合约编写
solidity
一.开发一个自己的ERC20标准代币
1.参考文档
https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20.md
2.详情请见代码注释
框架：
pragma solidity ^0.4.17;
contract simpletokenstruct{
string public name; //代币名称
string public simple; //代币代号
uint8 public decimals; //代币小数点位位数
uint256 public totalSupply; //代币总发行量
function balanceOf(address _owner) public view returns (uint256 balance){ //查看_owner账户的余额，返回余额
}
function transfer(address _to, uint256 _value) public returns (bool success){ //给_to地址转账_value，返回操作是否成功
}
function transferFrom(address _from, address _to, uint256 _value) public returns (bool success){
//从_from地址给_to地址转账_value，返回操作是否成功
}
function approve(address _spender, uint256 _value) public returns (bool success){
//允许_spender地址来操作_value大小的余额
}
function allowance(address _owner, address _spender) public view returns (uint256 remaining){
//用来查询_owner允许_spender使用多少个代币
}
event Transfer(address indexed _from, address indexed _to, uint256 _value); //定义了一个事件，暂时不管
event Approval(address indexed _owner, address indexed _spender, uint256 _value); //定义了一个事件，这里暂时不管
}
实际代码:
contract simpletoken is simpletokenstruct{
constructor() public{
name='chocobo'; //名字为choboco
simple='GIL'; //代号为GIL
decimals=1; //最多一位小数
totalSupply=1000; //总发行量1000
balanceOf[msg.sender]=totalSupply; //发布时，发布者拥有所有代币
}
mapping(address=>uint256) public balanceOf; //将地址映射为uint，代表账户余额
mapping(address=>mapping(address=>uint256)) internal approvemapping;
function transfer(address _to, uint256 _value) public returns (bool success){
require(_to != address(0)); //地址不为空
require(balanceOf[msg.sender]>=_value); //转账账户余额充足
require(balanceOf[_to]+_value>=balanceOf[_to]); //检测是否溢出
balanceOf[msg.sender]-=_value; //发送者减去数额
balanceOf[_to]+=_value; //接受者增加数额
emit Transfer(msg.sender,_to,_value); //暂时不管
success = true;
}
function transferFrom(address _from, address _to, uint256 _value) public returns (bool success){
require(_to != address(0));//地址不为空
require(balanceOf[_from]>=_value);//转账账户余额充足
require(approvemapping[_from][msg.sender]>=_value); //这里检测委托人的可操作的金额是否转账金额
require(balanceOf[_to]+_value>=balanceOf[_to]); //检测是否溢出
balanceOf[_from]-=_value;//发送者减去数额
balanceOf[_to]+=_value;//接受者增加数额
success = true;
}
function approve(address _spender, uint256 _value) public returns (bool success){
approvemapping[msg.sender][_spender]=_value; //映射可操作的代币，由调用者（msg.sender）指定_spender操作_value数额的代币
emit Approval(msg.sender,_spender,_value); //暂时不管
success = true;
}
function allowance(address _owner, address _spender) public view returns (uint256 remaining){
return approvemapping[_owner][_spender]; //查看剩余能调用多少代币
}
event Transfer(address indexed _from, address indexed _to, uint256 _value); //暂时不管
event Approval(address indexed _owner, address indexed _spender, uint256 _value); //暂时不管
}
运行结果
1.使用账号
部署之后，可以查看代币余额等
2.transfer操作
剩下的就不一一测试了
二.使用metamask发布自己的代币
1.在Chrome中安装metamask插件
2.注册之后可以看到自己的以太坊主网账号了，但是我们不用这个
3.切换到ropsten测试网络
3.没钱时，点
存入->
测试水管获取ether->
request 1 ether from faucet->
获取成功（高峰期可能失败，多试几次或者等一段时间即可）
4.在remix里选择injected web3，会自动关联metamask
可以看到账户变成了我们自己的账户
5.再部署时就会弹出metamask对话框，选择一下gas fee然后确认即可
gas fee 就是付给矿工的钱让他记录数据，太低了没人干活。但是这里是测试网络钱不是钱，所以低一点也无所谓
6.等待发布
7.之后，便可以看到我们的交易哈希等等了。
本章全部代码
pragma solidity ^0.4.17;
contract simpletokenstruct{
string public name;
string public simple;
uint8 public decimals;
uint256 public totalSupply;
//function balanceOf(address _owner) public view returns (uint256 balance){
//
//}
function transfer(address _to, uint256 _value) public returns (bool success){
}
function transferFrom(address _from, address _to, uint256 _value) public returns (bool success){
}
function approve(address _spender, uint256 _value) public returns (bool success){
}
function allowance(address _owner, address _spender) public view returns (uint256 remaining){
}
event Transfer(address indexed _from, address indexed _to, uint256 _value);
event Approval(address indexed _owner, address indexed _spender, uint256 _value);
}
contract simpletoken is simpletokenstruct{
constructor() public{
name='chocobo';
simple='GIL';
decimals=1;
totalSupply=1000;
balanceOf[msg.sender]=totalSupply;
}
mapping(address=>uint256) public balanceOf;
mapping(address=>mapping(address=>uint256)) internal approvemapping;
function transfer(address _to, uint256 _value) public returns (bool success){
require(_to != address(0));
require(balanceOf[msg.sender]>=_value);
require(balanceOf[_to]+_value>=balanceOf[_to]);
balanceOf[msg.sender]-=_value;
balanceOf[_to]+=_value;
emit Transfer(msg.sender,_to,_value);
success = true;
}
function transferFrom(address _from, address _to, uint256 _value) public returns (bool success){
require(_to != address(0));
require(balanceOf[_from]>=_value);
require(approvemapping[_from][msg.sender]>=_value);
require(balanceOf[_to]+_value>=balanceOf[_to]);
balanceOf[_from]-=_value;
balanceOf[_to]+=_value;
success = true;
}
function approve(address _spender, uint256 _value) public returns (bool success){
approvemapping[msg.sender][_spender]=_value;
emit Approval(msg.sender,_spender,_value);
success = true;
}
function allowance(address _owner, address _spender) public view returns (uint256 remaining){
return approvemapping[_owner][_spender];
}
event Transfer(address indexed _from, address indexed _to, uint256 _value);
event Approval(address indexed _owner, address indexed _spender, uint256 _value);
}