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将模板代码删除，上传本次测试的合约代码。
这是一个合乎ERC721规范的NFT合约代码，其中包含了几个罕用的标准接口和合约，上面是个合约的具体信息：
IERC65.sol
pragma solidity ^0.8.0;/** * @dev ERC165标准接口, 详见 * https://eips.ethereum.org/EIPS/eip-165[EIP]. * * 合约能够申明反对的接口，供其余合约查看 * */interface IERC165 { /** * @dev 如果合约实现了查问的`interfaceId`，则返回true * 规定详见：https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section] * */ function supportsInterface(bytes4 interfaceId) external view returns (bool);}IERC721.sol
// SPDX-License-Identifier: MITpragma solidity ^0.8.0;import "./IERC165.sol";/** * @dev ERC721标准接口. */interface IERC721 is IERC165 { event Transfer(address indexed from, address indexed to, uint256 indexed tokenId); event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId); event ApprovalForAll(address indexed owner, address indexed operator, bool approved); function balanceOf(address owner) external view returns (uint256 balance); function ownerOf(uint256 tokenId) external view returns (address owner); function safeTransferFrom( address from, address to, uint256 tokenId, bytes calldata data ) external; function safeTransferFrom( address from, address to, uint256 tokenId ) external; function transferFrom( address from, address to, uint256 tokenId ) external; function approve(address to, uint256 tokenId) external; function setApprovalForAll(address operator, bool _approved) external; function getApproved(uint256 tokenId) external view returns (address operator); function isApprovedForAll(address owner, address operator) external view returns (bool);}IERC721Receiver.sol
// SPDX-License-Identifier: MITpragma solidity ^0.8.0;// ERC721接收者接口：合约必须实现这个接口来通过平安转账接管ERC721interface IERC721Receiver { function onERC721Received( address operator, address from, uint tokenId, bytes calldata data ) external returns (bytes4);}IERC721Metadata.sol
// SPDX-License-Identifier: MITpragma solidity ^0.8.0;interface IERC721Metadata { function name() external view returns (string memory); function symbol() external view returns (string memory); function tokenURI(uint256 tokenId) external view returns (string memory);}Strings.sol
// SPDX-License-Identifier: MIT// OpenZeppelin Contracts (last updated v4.7.0) (utils/Strings.sol)pragma solidity ^0.8.4;/** * @dev String operations. */library Strings { bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef"; uint8 private constant _ADDRESS_LENGTH = 20; /** * @dev Converts a `uint256` to its ASCII `string` decimal representation. */ function toString(uint256 value) internal pure returns (string memory) { // Inspired by OraclizeAPI's implementation - MIT licence // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol if (value == 0) { return "0"; } uint256 temp = value; uint256 digits; while (temp != 0) { digits++; temp /= 10; } bytes memory buffer = new bytes(digits); while (value != 0) { digits -= 1; buffer[digits] = bytes1(uint8(48 + uint256(value % 10))); value /= 10; } return string(buffer); } /** * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation. */ function toHexString(uint256 value) internal pure returns (string memory) { if (value == 0) { return "0x00"; } uint256 temp = value; uint256 length = 0; while (temp != 0) { length++; temp >>= 8; } return toHexString(value, length); } /** * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length. */ function toHexString(uint256 value, uint256 length) internal pure returns (string memory) { bytes memory buffer = new bytes(2 * length + 2); buffer[0] = "0"; buffer[1] = "x"; for (uint256 i = 2 * length + 1; i > 1; --i) { buffer[i] = _HEX_SYMBOLS[value & 0xf]; value >>= 4; } require(value == 0, "Strings: hex length insufficient"); return string(buffer); } /** * @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation. */ function toHexString(address addr) internal pure returns (string memory) { return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH); }}Address.sol
// SPDX-License-Identifier: MITpragma solidity ^0.8.1;// Address库library Address { // 利用extcodesize判断一个地址是否为合约地址 function isContract(address account) internal view returns (bool) { uint size; assembly { size := extcodesize(account) } return size > 0; }}ERC721.sol
// SPDX-License-Identifier: MIT// by 0xAApragma solidity ^0.8.4;import "./IERC165.sol";import "./IERC721.sol";import "./IERC721Receiver.sol";import "./IERC721Metadata.sol";import "./Address.sol";import "./String.sol";contract ERC721 is IERC721, IERC721Metadata{ using Address for address; // 应用Address库，用isContract来判断地址是否为合约 using Strings for uint256; // 应用String库， // Token名称 string public override name; // Token代号 string public override symbol; // tokenId 到 owner address 的持有人映射 mapping(uint => address) private _owners; // address 到 持仓数量 的持仓量映射 mapping(address => uint) private _balances; // tokenID 到 受权地址 的受权映射 mapping(uint => address) private _tokenApprovals; // owner地址。到operator地址 的批量受权映射 mapping(address => mapping(address => bool)) private _operatorApprovals; /** * 构造函数，初始化`name` 和`symbol` . */ constructor(string memory name_, string memory symbol_) { name = name_; symbol = symbol_; } // 实现IERC165接口supportsInterface function supportsInterface(bytes4 interfaceId) external pure override returns (bool) { return interfaceId == type(IERC721).interfaceId || interfaceId == type(IERC165).interfaceId || interfaceId == type(IERC721Metadata).interfaceId; } // 实现IERC721的balanceOf，利用_balances变量查问owner地址的balance。 function balanceOf(address owner) external view override returns (uint) { require(owner != address(0), "owner = zero address"); return _balances[owner]; } // 实现IERC721的ownerOf，利用_owners变量查问tokenId的owner。 function ownerOf(uint tokenId) public view override returns (address owner) { owner = _owners[tokenId]; require(owner != address(0), "token doesn't exist"); } // 实现IERC721的isApprovedForAll，利用_operatorApprovals变量查问owner地址是否将所持NFT批量受权给了operator地址。 function isApprovedForAll(address owner, address operator) external view override returns (bool) { return _operatorApprovals[owner][operator]; } // 实现IERC721的setApprovalForAll，将持有代币全副受权给operator地址。调用_setApprovalForAll函数。 function setApprovalForAll(address operator, bool approved) external override { _operatorApprovals[msg.sender][operator] = approved; emit ApprovalForAll(msg.sender, operator, approved); } // 实现IERC721的getApproved，利用_tokenApprovals变量查问tokenId的受权地址。 function getApproved(uint tokenId) external view override returns (address) { require(_owners[tokenId] != address(0), "token doesn't exist"); return _tokenApprovals[tokenId]; } // 受权函数。通过调整_tokenApprovals来，受权 to 地址操作 tokenId，同时开释Approval事件。 function _approve( address owner, address to, uint tokenId ) private { _tokenApprovals[tokenId] = to; emit Approval(owner, to, tokenId); } // 实现IERC721的approve，将tokenId受权给 to 地址。条件：to不是owner，且msg.sender是owner或受权地址。调用_approve函数。 function approve(address to, uint tokenId) external override { address owner = _owners[tokenId]; require( msg.sender == owner || _operatorApprovals[owner][msg.sender], "not owner nor approved for all" ); _approve(owner, to, tokenId); } // 查问 spender地址是否被能够应用tokenId（他是owner或被受权地址）。 function _isApprovedOrOwner( address owner, address spender, uint tokenId ) private view returns (bool) { return (spender == owner || _tokenApprovals[tokenId] == spender || _operatorApprovals[owner][spender]); } /* * 转账函数。通过调整_balances和_owner变量将 tokenId 从 from 转账给 to，同时开释Tranfer事件。 * 条件: * 1. tokenId 被 from 领有 * 2. to 不是0地址 */ function _transfer( address owner, address from, address to, uint tokenId ) private { require(from == owner, "not owner"); require(to != address(0), "transfer to the zero address"); _approve(owner, address(0), tokenId); _balances[from] -= 1; _balances[to] += 1; _owners[tokenId] = to; emit Transfer(from, to, tokenId); } // 实现IERC721的transferFrom，非平安转账，不倡议应用。调用_transfer函数 function transferFrom( address from, address to, uint tokenId ) external override { address owner = ownerOf(tokenId); require( _isApprovedOrOwner(owner, msg.sender, tokenId), "not owner nor approved" ); _transfer(owner, from, to, tokenId); } /** * 平安转账，平安地将 tokenId 代币从 from 转移到 to，会查看合约接收者是否理解 ERC721 协定，以避免代币被永恒锁定。调用了_transfer函数和_checkOnERC721Received函数。条件： * from 不能是0地址. * to 不能是0地址. * tokenId 代币必须存在，并且被 from领有. * 如果 to 是智能合约, 他必须反对 IERC721Receiver-onERC721Received. */ function _safeTransfer( address owner, address from, address to, uint tokenId, bytes memory _data ) private { _transfer(owner, from, to, tokenId); require(_checkOnERC721Received(from, to, tokenId, _data), "not ERC721Receiver"); } /** * 实现IERC721的safeTransferFrom，平安转账，调用了_safeTransfer函数。 */ function safeTransferFrom( address from, address to, uint tokenId, bytes memory _data ) public override { address owner = ownerOf(tokenId); require( _isApprovedOrOwner(owner, msg.sender, tokenId), "not owner nor approved" ); _safeTransfer(owner, from, to, tokenId, _data); } // safeTransferFrom重载函数 function safeTransferFrom( address from, address to, uint tokenId ) external override { safeTransferFrom(from, to, tokenId, ""); } /** * 铸造函数。通过调整_balances和_owners变量来铸造tokenId并转账给 to，同时开释Tranfer事件。铸造函数。通过调整_balances和_owners变量来铸造tokenId并转账给 to，同时开释Tranfer事件。 * 这个mint函数所有人都能调用，理论应用须要开发人员重写，加上一些条件。 * 条件: * 1. tokenId尚不存在。 * 2. to不是0地址. */ function _mint(address to, uint tokenId) internal virtual { require(to != address(0), "mint to zero address"); require(_owners[tokenId] == address(0), "token already minted"); _balances[to] += 1; _owners[tokenId] = to; emit Transfer(address(0), to, tokenId); } // 销毁函数，通过调整_balances和_owners变量来销毁tokenId，同时开释Tranfer事件。条件：tokenId存在。 function _burn(uint tokenId) internal virtual { address owner = ownerOf(tokenId); require(msg.sender == owner, "not owner of token"); _approve(owner, address(0), tokenId); _balances[owner] -= 1; delete _owners[tokenId]; emit Transfer(owner, address(0), tokenId); } // _checkOnERC721Received：函数，用于在 to 为合约的时候调用IERC721Receiver-onERC721Received, 以防 tokenId 被不小心转入黑洞。 function _checkOnERC721Received( address from, address to, uint tokenId, bytes memory _data ) private returns (bool) { if (to.isContract()) { return IERC721Receiver(to).onERC721Received( msg.sender, from, tokenId, _data ) == IERC721Receiver.onERC721Received.selector; } else { return true; } } /** * 实现IERC721Metadata的tokenURI函数，查问metadata。 */ function tokenURI(uint256 tokenId) public view virtual override returns (string memory) { require(_owners[tokenId] != address(0), "Token Not Exist"); string memory baseURI = _baseURI(); return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : ""; } /** * 计算{tokenURI}的BaseURI，tokenURI就是把baseURI和tokenId拼接在一起，须要开发重写。 * BAYC的baseURI为ipfs://QmeSjSinHpPnmXmspMjwiXyN6zS4E9zccariGR3jxcaWtq/ */ function _baseURI() internal view virtual returns (string memory) { return ""; }}编译、部署合约，设置NFT名称为HHTest，符号为HH。
合约部署胜利后，进入ABI操作页面，开始测试合约的mint函数，测试铸造一个NFT。
铸造实现后应用合约地址在opensea的测试链版中查问，能够发现咱们刚刚铸造的NFT能够在其中查问进去，因为合约用的是无聊猿的tokenURI地址，所以显示的是无聊猿的信息。