Solidity

Question

我正在使用 Truffle 和 upgradable Openzeppelin contracts。我有两份合同。

Token.sol:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.2;

import "@openzeppelin/contracts-upgradeable/token/ERC20/ERC20Upgradeable.sol";
import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";

contract MyToken is Initializable, ERC20Upgradeable {
    /// @custom:oz-upgrades-unsafe-allow constructor
    constructor() initializer {}

    function initialize() initializer public {
        __ERC20_init("MyToken", "MTK");

        _mint(msg.sender, 10000000 * 10 ** decimals());
    }
}

AnotherContract.sol:

pragma solidity ^0.8.2;
import "./IAnotherContract.sol";

contract AnotherContract is IAnotherContract {
  function doSomethingIfBalanceIsEnough()
    external
    returns (string memory)
  {
    // ... 
  }
}

我如何检查一个用户有多少 MTK 个令牌？我需要在 doSomethingIfBalanceIsEnough 函数中检查它。

Answer 1

代币合约implements一个balanceOf()函数，即returns地址的代币余额。

您可以从 AnotherContract 向 MyToken 地址进行外部调用，调用其 balanceOf() 函数，将用户地址传递给它。

pragma solidity ^0.8.2;
import "./IAnotherContract.sol";

interface IERC20 {
    function balanceOf(address) external view returns (uint256);
}

contract AnotherContract is IAnotherContract {
    function doSomethingIfBalanceIsEnough()
      external
      returns (string memory)
    {
        uint256 userBalance = IERC20(myTokenAddress).balanceOf(msg.sender);
        if (userBalance > 0) {
            // ...
        }
    }
}

Solidity - 使用 openzeppelin 检查用户地址的余额

Solidity - Check balance of a user address using openzeppelin

blockchain

ethereum

truffle

openzeppelin