使ERC721灵魂绑定时出错
使ERC721灵魂绑定时出错
提问于 2023-02-16 05:07:01
我正在使用openzeppelin和solidity ^0.8.13中的铸造厂制作一个灵魂约束的NFT。
为此，我正在重写_beforeTokenTransfer，但是在这个函数上，我得到了一个错误。
函数已指定重写，但不覆盖任何内容。
我的守则：-
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;
import "openzeppelin-contracts/contracts/token/ERC721/ERC721.sol";
import "openzeppelin-contracts/contracts/token/ERC721/extensions/ERC721URIStorage.sol";
import "openzeppelin-contracts/contracts/utils/Counters.sol";
import "openzeppelin-contracts/contracts/access/Ownable.sol";
contract MyToken is ERC721, ERC721URIStorage, ERC721Burnable, Ownable {
using Counters for Counters.Counter;
Counters.Counter private _tokenIdCounter;
constructor() ERC721("MyToken", "MTK") {}
function safeMint(address to, string memory uri) public onlyOwner {
uint256 tokenId = _tokenIdCounter.current();
_tokenIdCounter.increment();
_safeMint(to, tokenId);
_setTokenURI(tokenId, uri);
}
// The following functions are overrides required by Solidity.
function _burn(uint256 tokenId) internal override(ERC721, ERC721URIStorage) {
super._burn(tokenId);
}
function tokenURI(uint256 tokenId)
public
view
override(ERC721, ERC721URIStorage)
returns (string memory)
{
return super.tokenURI(tokenId);
}
function _beforeTokenTransfer(
address from,
address to,
uint256
) internal pure override {
require(
from == address(0) || to == address(0),
"transfer not allowed"
);
}
}我也尝试了使用override(ERC721, ERC721URIStorage)的代码，但它也不起作用。
我需要帮助找出为什么我要得到这个错误，为什么函数不接受重写。
回答 1
Ethereum用户
回答已采纳
发布于 2023-02-16 05:14:36
覆盖(ERC721，ERC721URIStorage)
帮你修好它：
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.13;
import "openzeppelin-contracts/contracts/token/ERC721/ERC721.sol";
import "openzeppelin-contracts/contracts/token/ERC721/extensions/ERC721URIStorage.sol";
import "openzeppelin-contracts/contracts/utils/Counters.sol";
import "openzeppelin-contracts/contracts/access/Ownable.sol";
contract MyToken is ERC721, ERC721URIStorage, Ownable {
using Counters for Counters.Counter;
Counters.Counter private _tokenIdCounter;
constructor() ERC721("MyToken", "MTK") {}
function safeMint(address to, string memory uri) public onlyOwner {
uint256 tokenId = _tokenIdCounter.current();
_tokenIdCounter.increment();
_safeMint(to, tokenId);
_setTokenURI(tokenId, uri);
}
// The following functions are overrides required by Solidity.
function _burn(uint256 tokenId) internal override(ERC721, ERC721URIStorage) {
super._burn(tokenId);
}
function tokenURI(uint256 tokenId)
public
view
override(ERC721, ERC721URIStorage)
returns (string memory)
{
return super.tokenURI(tokenId);
}
function _beforeTokenTransfer(address from, address to,uint256 , uint256)
internal
pure
override(ERC721)
{
require(
from == address(0) || to == address(0),
"transfer not allowed"
);
}
}页面原文内容由Ethereum提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://ethereum.stackexchange.com/questions/145013
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