4.4

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

contract MyNFT is ERC721{
    
    using Strings for uint256;

    address owner; 
    uint256 public maxSupply = 10; // 最大發行量
    bool private isOpened = false; // 盲盒是否打開, 預設就是沒開

    uint256 public counter = 0;

    modifier onlyOwner { // 只有owner才可以操作的function
        require(msg.sender == owner);
        _;
    }

    constructor (string memory _name, string memory _symbol) ERC721(_name, _symbol){
        owner = msg.sender; // 佈合約的地址, 就是msg.sender
    }

    // 盲盒打開, 圖片就會變, tokenURI改變
    function openBlindBox() external onlyOwner {
        isOpened = true;
    }

    // 設定NFT的baseURI(盲盒)
    function _baseURI() internal pure overrider returns (string memory) {
        return ipfs://QmahbazMeYgjSyKuSLZ6EqGWVKYYKEtDnH1gXdGGioiYnX"; // 
    }

    // 查看NFT MetaData網址
    function tokenURI(uint256 tokenId) public view override returns (string memory) {
        if(!isOpenid) { // 如果盲盒沒有被打開, 就回傳網址
            return _baseURI(); // 不管有沒有開, 都回傳Json檔
        }
        return string(abi.encodePacked("ipfs://QmahbazMeYgjSyKuSLZ6EqGWVKYYKEtDnH1gXdGGioiYnX");
    }

    // 實作mint function, 主要用來demo確認用
    function mint (uint256 amount) external {
        require(amount + count <= maxSupply, "over max supply.");
        // 迴圏批量鑄造NFT
        for(uint256 i = 0; i < amount ; i++){
            //鑄造NFT, counter為NFT的tokenId
            _mint(msg.sender, counter);
            counter ++;
        }
    }
}// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

contract MyNFT is ERC721{
    
    using Strings for uint256;

    address owner; 
    uint256 public maxSupply = 10; // 最大發行量
    bool private isOpened = false; // 盲盒是否打開, 預設就是沒開

    uint256 public counter = 0;

    modifier onlyOwner { // 只有owner才可以操作的function
        require(msg.sender == owner);
        _;
    }

    constructor (string memory _name, string memory _symbol) ERC721(_name, _symbol){
        owner = msg.sender; // 佈合約的地址, 就是msg.sender
    }

    // 盲盒打開, 圖片就會變, tokenURI改變
    function openBlindBox() external onlyOwner {
        isOpened = true;
    }

    // 設定NFT的baseURI(盲盒)
    function _baseURI() internal pure overrider returns (string memory) {
        return ipfs://QmahbazMeYgjSyKuSLZ6EqGWVKYYKEtDnH1gXdGGioiYnX"; // 
    }

    // 查看NFT MetaData網址
    function tokenURI(uint256 tokenId) public view override returns (string memory) {
        if(!isOpenid) { // 如果盲盒沒有被打開, 就回傳網址
            return _baseURI(); // 不管有沒有開, 都回傳Json檔
        }
        return string(abi.encodePacked("ipfs://QmahbazMeYgjSyKuSLZ6EqGWVKYYKEtDnH1gXdGGioiYnX");
    }

    // 實作mint function, 主要用來demo確認用
    function mint (uint256 amount) external {
        require(amount + count <= maxSupply, "over max supply.");
        // 迴圏批量鑄造NFT
        for(uint256 i = 0; i < amount ; i++){
            //鑄造NFT, counter為NFT的tokenId
            _mint(msg.sender, counter);
            counter ++;
        }
    }
}

Create an NFT Lootbox for blockchain games or NFT trading card platforms (NBA Topshot clone)

Solidity 實戰系列工作坊第 3 場精彩重播: ERC20 同質化代幣與 ERC721 NFT 非同質化代幣