如何与我在混音中的第一个defi智能合同互动？

Question

我在网上找到了这个tuto：https://cryptomarketpool.com/create-a-defi-bank-that-pays-interest-yield-farm/和我通过混合在testnet上部署了我的令牌和智能合同。

问题是，我完全是个菜鸟，我真的不知道如何与这个合同互动。不确定hasStaked和isStaking之间有什么区别。

当试图以某种地址和金额执行合同时，如下所示。交易进行得很顺利，但什么也没发生。我的链接不会从我的钱包里消失。

下一步是用python编写一个小API，但首先我需要了解如何使用这个智能契约。

以下是我最聪明的合同：

pragma solidity ^0.6.12;


interface IERC20 {
    function totalSupply() external view returns (uint);
    function balanceOf(address account) external view returns (uint);
    function transfer(address recipient, uint amount) external returns (bool);
    function allowance(address owner, address spender) external view returns (uint);
    function approve(address spender, uint amount) external returns (bool);
    function transferFrom(
        address sender,
        address recipient,
        uint amount
    ) external returns (bool);
    event Transfer(address indexed from, address indexed to, uint value);
    event Approval(address indexed owner, address indexed spender, uint value);
}


contract mycontract {
    
    // call it DefiBank
    string public name = "DefiBank";
    
    // create 2 state variables
    address public LINK;
    address public bankToken;


    address[] public stakers;
    mapping(address => uint) public stakingBalance;
    mapping(address => bool) public hasStaked;
    mapping(address => bool) public isStaking;


    // in constructor pass in the address for LINK token and your custom bank token
    // that will be used to pay interest
    constructor() public {
        LINK = 0x01BE23585060835E02B77ef475b0Cc51aA1e0709;
        bankToken = 0x5A39644Axxxxxxxxxxxxxxx849cBf102be;

    }


    // allow user to stake LINK tokens in contract
    
    function stakeTokens(uint _amount) public {

        // Trasnfer LINK tokens to contract for staking
        IERC20(LINK).transferFrom(msg.sender, address(this), _amount);

        // Update the staking balance in map
        stakingBalance[msg.sender] = stakingBalance[msg.sender] + _amount;

        // Add user to stakers array if they haven't staked already
        if(!hasStaked[msg.sender]) {
            stakers.push(msg.sender);
        }

        // Update staking status to track
        isStaking[msg.sender] = true;
        hasStaked[msg.sender] = true;
    }

        // allow user to unstake total balance and withdraw LINK from the contract
    
     function unstakeTokens() public {

        // get the users staking balance in LINK
        uint balance = stakingBalance[msg.sender];
    
        // reqire the amount staked needs to be greater then 0
        require(balance > 0, "staking balance can not be 0");
    
        // transfer LINK tokens out of this contract to the msg.sender
        IERC20(usdc).transfer(msg.sender, balance);
    
        // reset staking balance map to 0
        stakingBalance[msg.sender] = 0;
    
        // update the staking status
        isStaking[msg.sender] = false;

} 


    // Issue bank tokens as a reward for staking
    
    function issueInterestToken() public {
        for (uint i=0; i<stakers.length; i++) {
            address recipient = stakers[i];
            uint balance = stakingBalance[recipient];
            
    // if there is a balance transfer the SAME amount of bank tokens to the account that is staking as a reward
            
            if(balance >0 ) {
                IERC20(bankToken).transfer(recipient, balance);
                
            }
            
        }
        
    }

    event Received(address, uint);
    receive() external payable {
        emit Received(msg.sender, msg.value);
    }
} 

Answer 1

我在这一行看到你的合同有错误。

// transfer LINK tokens out of this contract to the msg.sender
 IERC20(usdc).transfer(msg.sender, balance);

如果要使用链接令牌，则不能使用usdc变量，但必须使用以下链接变量来更改它：

// transfer LINK tokens out of this contract to the msg.sender
IERC20(LINK).transfer(msg.sender, balance);

对于利害关系问题，用户必须批准使用您的令牌的合同。要做到这一点，您必须进入链接智能契约(在testnet上)，并调用审批函数连接您的钱包和插入智能契约的地址和金额。

hasStaked和isStaking的区别是：

• hasStaked:是一个映射关系，涉及到所有用户，他们已经将令牌作了赌注。如果它们是在以前的时间中进行的，用户就不会被添加到标记映射中；
• isStaking:是一个映射关系，它涉及所有用户，他们(目前)将您的令牌存储在智能契约中。