Question

我写了一个erc20代币合同，并部署在rinkeby tetstnet中。我给toatl供应量= 1000000，但是我的令牌余额在元掩码中显示为0。我如何获得令牌并告诉我如何获得令牌。以下是我的合同

pragma solidity ^0.5.0;
contract COCOTOKEN {
string public constant symbol = "COCO";
  string public constant name = "COCOTOKEN";
  uint8 public constant decimals = 18;
  uint256 totalSupply = 1000000;
  address public owner;
  mapping(address => uint256) balances;
  mapping(address => mapping (address => uint256)) allowed;
  modifier onlyOwner {
        require(msg.sender == owner);
        _;
    }
event Transfer(address indexed _from, address indexed _to, uint256 _value);
event Approval(address indexed _owner, address indexed _spender, uint256 _value);
constructor() public{
  owner = msg.sender;
  balances[owner] = totalSupply;
}
function balanceOf(address _owner) public view returns (uint256 balance) {
    return balances[_owner];
}
function transfer(address _to, uint256 _amount) public returns (bool success) {
    if (balances[msg.sender] >= _amount
        && _amount > 0
        && balances[_to] + _amount > balances[_to]) {
        balances[msg.sender] -= _amount;
        balances[_to] += _amount;
       emit Transfer(msg.sender, _to, _amount);

        return true;
    } else {
        return false;
    }
}
function transferFrom(
    address _from,
    address _to,
    uint256 _amount
) public returns (bool success) {
    if (balances[_from] >= _amount
        && allowed[_from][msg.sender] >= _amount
        && _amount > 0
        && balances[_to] + _amount > balances[_to]) {
        balances[_from] -= _amount;
        allowed[_from][msg.sender] -= _amount;
        balances[_to] += _amount;
        emit Transfer(_from, _to, _amount);
        return true;
    } else {
        return false;
    }
}
function approve(address _spender, uint256 _amount) public returns (bool success) {
    allowed[msg.sender][_spender] = _amount;
    emit Approval(msg.sender, _spender, _amount);
    return true;
}
function allowance(address _owner, address _spender) public view returns (uint256 remaining) {
    return allowed[_owner][_spender];
}
}

，并且已部署的合同地址为“ 0xc3384a37d041b99d437734a80e88b39e0efa630d”。为什么令牌余额显示为0。在rinkeby etehrscan中，它显示liks 链上令牌属性检查结果：总供应量= 0 名称= COCOTOKEN 符号= COCO 小数= 18 ERC-165接口= {不可用} 实现ERC-721 = {不可用}。有人可以告诉我如何添加令牌吗？

Answer 1

因为那是您醚的很小一部分。只需从水龙头转移乙醚。或仅以wei单位1000000000000000000进行转移，那么您的屏幕上就会看到1个以太币。

Answer 2

您需要将totalSupply的小数位数增加18位。有关decimal和totalSupply的更多说明，请选中此Answer。

Answer 3

您在totalSupply处设置的值太低，可以检查erc20令牌标准here。在构造函数中，他们像下面的代码一样设置totalSupply：

constructor() public {
        symbol = "FIXED";
        name = "Example Fixed Supply Token";
        decimals = 18;
        _totalSupply = 1000000 * 10**uint(decimals);
        balances[owner] = _totalSupply;
        emit Transfer(address(0), owner, _totalSupply);
    }

Answer 4

您提供的总供应量就像totalsupply = 1000000 * 10 ^ -18等于0.0000000000001，因此当您尝试执行任何交易时，它显然将显示为零。

Answer 5

这是使用OpenZeppelin的完整实现，它将总供应量设置为1000000，并在合同初始化时将代币分配给您。

pragma solidity 0.5.2;

import "https://github.com/OpenZeppelin/openzeppelin-solidity/contracts/token/ERC20/ERC20.sol";

contract TokenMock is ERC20
{
    constructor () public {
        _mint(msg.sender, 1000000);
    }
}

令牌余额在rinkeby etherscan中显示为0

5 个答案: