Contract Name:
NiMingToken
Contract Source Code:
File 1 of 1 : NiMingToken
pragma solidity ^0.4.23;
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);
}
library SafeMath {
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;
}
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;
}
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
assert(b <= a);
return a - b;
}
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
assert(c >= a);
return c;
}
}
contract StandardToken is Token {
using SafeMath for uint256;
function transfer(address _to, uint256 _value) public returns (bool success) {
require(_to != address(0));
require(balances[msg.sender] >= _value);
balances[msg.sender] = balances[msg.sender].sub(_value);//从消息发送者账户中减去token数量_value
balances[_to] = balances[_to].add(_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(_to != address(0));
require(balances[_from] >= _value && allowed[_from][msg.sender] >= _value);
balances[_to] = balances[_to].add(_value);//接收账户增加token数量_value
balances[_from] = balances[_from].sub(_value); //支出账户_from减去token数量_value
allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_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)
{
require((_value == 0) || (allowed[msg.sender][_spender] == 0));
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 NiMingToken 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) {
require((_value == 0) || (allowed[msg.sender][_spender] == 0));
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;
}
}