DeFi单双币流动性质押挖矿系统模式开发（详细案例）

通过将PI和USDT两种货币同时质押到指定的矿池中，双币质押挖矿是一种新型的数字货币挖矿方式，参与挖矿活动，获得相应的收益。

简单的代码示例，可以帮助您理解PI双币质押挖矿的实现方式：

scssCopy codepragma solidity ^0.8.0;

    struct Staker {
        uint256 piAmount;
        uint256 usdtAmount;
        uint256 lastUpdateTime;
        uint256 rewardEarned;
    }    mapping(address => Staker) public stakers;
    uint256 public totalStakedPi;
    uint256 public totalStakedUsdt;
    uint256 public rewardRate = 10; // 每日收益率

    constructor(address _piToken, address _usdtToken) {
        piToken = IERC20(_piToken);
        usdtToken = IERC20(_usdtToken);
    }

    function stake(uint256 _piAmount, uint256 _usdtAmount) external {
            require(_piAmount > 0 || _usdtAmount > 0, "Invalid amount");
                    updateReward(msg.sender);


    function claimReward() external {
            updateReward(msg.sender);

        uint256 reward = stakers[msg.sender].rewardEarned;
        stakers[msg.sender].rewardEarned = 0;
        piToken.transfer(msg.sender, reward);
    }

    function updateReward(address _account) internal {
        uint256 rewardPerToken = getRewardPerToken();
        stakers[_account].rewardEarned += getRewardEarned(_account, rewardPerToken);
        stakers[_account].lastUpdateTime = block.timestamp;
    }

    function getRewardPerToken() internal view returns (uint256) {
        uint256 totalStaked = totalStakedPi + totalStakedUsdt;
        if (totalStaked
        
        
        if (_piAmount > 0) {
            piToken.transferFrom(msg.sender, address(this), _piAmount);
            stakers[msg.sender].piAmount += _piAmount;
            totalStakedPi += _piAmount;
        }

        if (_usdtAmount > 0) {
            usdtToken.transferFrom(msg.sender, address(this), _usdtAmount);
            stakers[msg.sender].usdtAmount += _usdtAmount;
            totalStakedUsdt += _usdtAmount;
        }
    }

    function withdraw(uint256 _piAmount, uint256 _usdtAmount) external {
            require(_piAmount > 0 || _usdtAmount > 0, "Invalid amount");
                    updateReward(msg.sender);

        if (_piAmount > 0) {
                    require(stakers[msg.sender].piAmount >= _piAmount, "Insufficient balance");
            piToken.transfer(msg.sender, _piAmount);
            stakers[msg.sender].piAmount -= _piAmount;
            totalStakedPi -= _piAmount;
        }

        if (_usdtAmount > 0) {
                    require(stakers[msg.sender].usdtAmount >= _usdtAmount, "Insufficient balance");
            usdtToken.transfer(msg.sender, _usdtAmount);
            stakers[msg.sender].usdtAmount -= _usdtAmount;
            totalStakedUsdt -= _usdtAmount;
        }
    }
        

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