3分钟Solidity: 10.2 荷兰式拍卖

欢迎订阅专栏：3分钟Solidity--智能合约--Web3区块链技术必学

如需获取本内容的最新版本，请参见 Cyfrin.io 上的荷兰式拍卖（代码示例）

NFT荷兰式拍卖。

拍卖

1. NFT卖家部署此合约，为NFT设定起拍价。
2. 拍卖持续7天。
3. NFT价格随时间递减。
4. 参与者存入高于智能合约计算的当前价格的ETH即可购买。
5. 当有买家购买NFT时，拍卖结束。

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.26;

interface IERC721 {
    function transferFrom(address _from, address _to, uint256 _nftId)
        external;
}

contract DutchAuction {
    uint256 private constant DURATION = 7 days;

    IERC721 public immutable nft;
    uint256 public immutable nftId;

    address payable public immutable seller;
    uint256 public immutable startingPrice;
    uint256 public immutable startAt;
    uint256 public immutable expiresAt;
    uint256 public immutable discountRate;

    constructor(
        uint256 _startingPrice,
        uint256 _discountRate,
        address _nft,
        uint256 _nftId
    ) {
        seller = payable(msg.sender);
        startingPrice = _startingPrice;
        startAt = block.timestamp;
        expiresAt = block.timestamp + DURATION;
        discountRate = _discountRate;

        require(
            _startingPrice >= _discountRate * DURATION, "starting price < min"
        );

        nft = IERC721(_nft);
        nftId = _nftId;
    }

    function getPrice() public view returns (uint256) {
        uint256 timeElapsed = block.timestamp - startAt;
        uint256 discount = discountRate * timeElapsed;
        return startingPrice - discount;
    }

    function buy() external payable {
        require(block.timestamp < expiresAt, "auction expired");

        uint256 price = getPrice();
        require(msg.value >= price, "ETH < price");

        nft.transferFrom(seller, msg.sender, nftId);
        uint256 refund = msg.value - price;
        if (refund > 0) {
            payable(msg.sender).transfer(refund);
        }
        selfdestruct(seller);
    }
}

Remix Lite 尝试一下

• DutchAuction.sol荷兰拍卖网