Escrow.sol:如果您发送值，则应支付被调用的函数，并且所发送的值应小于当前余额。

Question

我正在尝试使用Escrow.sol令牌来实现ERC20。当我在Remix上部署Escrow.sol并想要存放10个令牌时，The called function should be payable if you send value and the value you send should be less than your current balance.就会显示出退出的功能。

我怎么才能修好它？

下面是我的erc20.sol

// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.0;

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

contract MyToken is ERC20 {
    constructor() ERC20("GINWEI", "GW") public payable {
        _mint(msg.sender, 1000);
    }
}

下面是escr.sol

// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.0;

import "./erc20.sol";

contract MyEscrow {

    mapping(address => mapping(address => uint256)) public _deposits;
    address payable payee = payable(msg.sender);
    MyToken token;

    function deposit(uint256 amount) public payable {
        token.approve(address(this), amount);
        token.transfer(address(this), amount);
        _deposits[payee][address(token)] += amount;
    }

    function depositsOf() public view returns (uint256) {
        return _deposits[payee][address(token)];
    }

    function withdraw(uint256 payment) public payable {
        _deposits[payee][address(token)] -= payment;
        payee.transfer(payment);
    }
}

Answer 1

您的MyEscrow智能合同有任何问题，让我解释一下：

• 当您声明此语句MyToken token;类似于存储变量时，必须使用ERC20 20‘S智能联系人地址实例化它，以便使用ERC20方法。如何解决此问题的示例：MyToken token = MyToken([addressERC20SmartContract]);
• token.approve(address(this), amount);这个声明是错误的，因为您正在批准您的MyEscrow智能合同来传输它没有的令牌数量。要解决这个问题，用户必须从您的approve()智能契约(本例中为MyToken智能契约)调用D9。调用approve时，必须在以下参数内传递这些值：
  • 用户：MyEscrow智能合同地址；
  • 金额:多少令牌MyEscrow可以从您的钱包转移。

• 最后，在withdraw函数中，将ERC20从智能契约转移到用户钱包中，您可以使用transfer() ERC20方法，并在其中传递msg.sender和要提取的值。

我已经以这样的方式更正了您的MyEscrow智能合同：

// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.0;

import "./erc20.sol";

contract MyEscrow {

    mapping(address => mapping(address => uint256)) public _deposits;
    address payable payee = payable(msg.sender);
    MyToken token;

    constructor(address _myToken) {
        token = MyToken(_myToken); 
    }

    function deposit(uint256 amount) public payable {
        token.transferFrom(msg.sender, address(this), amount);
        _deposits[payee][address(token)] += amount;
    }

    function depositsOf() public view returns (uint256) {
        return _deposits[payee][address(token)];
    }

    function withdraw(uint256 payment) public payable {
        _deposits[payee][address(token)] -= payment;
        token.transfer(msg.sender, payment);
    }
}

Answer 2

经过几次尝试，我将@Kerry99 99中的溶胶和我的原始代码组合在一起，它运行得非常完美！

func approve()已经过时了。

contract MyEscrow {

    mapping(address => mapping(address => uint256)) public _deposits;
    address payable payee = payable(msg.sender);
    address tokenaddress = 0x...;
    MyToken token = MyToken(tokenaddress);

    function deposit(uint256 amount) public payable {
        token.approve(msg.sender, address(this), amount);
        token.transferFrom(msg.sender, address(this), amount);
        _deposits[payee][tokenaddress] += amount;
    }

    function depositsOf() public view returns (uint256) {
        return _deposits[payee][tokenaddress];
    }

    function withdraw(uint256 payment) public payable {
        _deposits[payee][tokenaddress] -= payment;
        token.transfer(msg.sender, payment);
    }
}