Question

在Remix Ethereum Firefox中部署该令牌后，我需要知道该令牌的余额。我想知道在哪里添加checkBalance函数。请帮助伙计们。这是我的第一个ERC20智能合约。

pragma solidity ^0.5.0;

contract TusharCoin {

  uint256 public totalSupply;  
  string public name;  
  string public symbol;  
  uint32 public decimals;
  address public owner;

  mapping(address => uint256 ) balances;

  event Transfer(address to, uint256 amount);

  constructor () public {
    symbol  = "TUSHAR";  
    name = "TusharCoin";  
    decimals = 5;  
    totalSupply = 100000000000;
    owner = msg.sender;  
    balances[msg.sender] = totalSupply;
    emit Transfer(msg.sender, totalSupply);
    }
 }

Answer 1

您的令牌当前不是ERC20令牌，因为它尚未完全实现ERC20标准。

要将balanceOf函数添加到现有合同中，可以添加以下内容：

    function balanceOf(address account) public view returns (uint256) {
        return balances[account];
    }

如果要创建自己的ERC20实现，则应考虑使用SafeMath，有关详细信息，请参阅文档：https://docs.openzeppelin.com/contracts/2.x/utilities#math

如果您正在创建ERC20令牌，则可能需要查看OpenZeppelin Contracts实施以查看它是否满足您的需求。有关详细信息，请参见文档：https://docs.openzeppelin.com/contracts/2.x/tokens#ERC20

下面是您可以使用Remix部署的示例ERC20令牌的示例，该令牌是从OpenZeppelin Contracts实现继承而来的，使用您指定的名称，符号，小数和totalSupply：

pragma solidity ^0.5.0;

import "https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v2.3.0/contracts/token/ERC20/ERC20.sol";
import "https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v2.3.0/contracts/token/ERC20/ERC20Detailed.sol";

contract Token is ERC20, ERC20Detailed {

    constructor () public ERC20Detailed("Tushar Token", "TUSHAR", 5) {
        _mint(msg.sender, 1000000 * (10 ** uint256(decimals())));
    }
}

如果您对使用OpenZeppelin有疑问，可以在社区论坛中提问：https://forum.openzeppelin.com/

披露：我是OpenZeppelin的社区经理

Answer 2

下面，我提到checkBalance函数。在ERC20标准中，将checkBalance函数声明为balanceOf函数。在功能上，视图意味着只能读不写

function balanceOf(address accountAddress) public view returns (uint256) {
    return balances[accountAddress];
}

完整的源代码。

pragma solidity ^0.5.0;

contract TusharCoin {

  uint256 public totalSupply;  
  string public name;  
  string public symbol;  
  uint32 public decimals;
  address public owner;

  mapping(address => uint256 ) balances;

  event Transfer(address to, uint256 amount);

  constructor () public {
    symbol  = "TUSHAR";  
    name = "TusharCoin";  
    decimals = 5;  
    totalSupply = 100000000000;
    owner = msg.sender;  
    balances[msg.sender] = totalSupply;
    emit Transfer(msg.sender, totalSupply);
    }

    function balanceOf(address accountAddress) public view returns (uint256) {
        return balances[accountAddress];
    }
 }

如果您需要ERC20的完整代码。让我知道。

如何向此ERC20智能合约添加checkBalance功能

2 个答案: