带函数类型误差

Question

我一直在学习一门课程，我遵循了他们的代码，不知怎么的，当我编译我的代码时，它给了我一个错误，而我所遵循的课程没有错误，请有人帮助我。

pragma solidity ^0.8.7;


import './ERC165.sol';
import './IERC721.sol';

contract ERC721 is ERC165, IERC721 {

        function ownerOf(uint256 _tokenId) public override view returns (address) {
            address owner = _tokenOwner[_tokenId];
            require(owner != address(0), 'owner query for non-existent token');
            return owner;
        }

    // mapping in solidity creates a hash table of key pair values

    // Mapping from token id to the owner
    mapping(uint => address) private _tokenOwner;


    // Mapping from owner to number of owned tokens
    mapping(address => uint256) private _OwnedTokensCount;

    mapping(uint256 => address) private _tokenApprovals;

    constructor() {
        _registerInterface(bytes4(keccak256('balanceOf(bytes4)')^
        keccak256('ownerOf(bytes4)')^keccak256('transferFrom(bytes4)')));
    }

    function balanceOf(address _owner) public override view returns (uint256) {
        require(_owner != address(0), 'owner query for non-existant token');
        return _OwnedTokensCount[_owner];
    }
    
    function _exists(uint256 tokenId) internal view returns(bool) {
       // setting the address of nft owner to check the mapping
       // of the address from tokenOwner at the tokenId
       address owner = _tokenOwner[tokenId]; 
       // return truthiness tha address is not zero
       return owner != address(0);
    }



    function _mint(address to, uint256 tokenId) internal virtual {
        require(to != address(0), 'ERC721: minting to the zero address');
        require(!_exists(tokenId), 'ERC721: token already minted');
        _tokenOwner[tokenId] = to;
        _OwnedTokensCount[to] += 1;

        emit Transfer(address(0), to, tokenId);
    }

    function _transferFrom(address _from, address _to, uint256 _tokenId) external payable
    {
        require(_to != address(0), 'Error - ERC721 transfer to the zero address');
        require(ownerOf(_tokenId) == _from, 'Trying to transfer a token the address does not own!');

        _OwnedTokensCount[_from] -= 1;
        _OwnedTokensCount[_from] += 1;
        
        _tokenOwner[_tokenId] = _to;

        emit Transfer(_from, _to, _tokenId);
    }


    function transferFrom(address _from, address _to, uint256 _tokenId) override public {
        require(msg.sender, _tokenId);
        transferFrom(_from, _to, _tokenId);
    }

    function approve(address _to, uint256 tokenId) public {
        address owner = ownerOf(tokenId);
        require(_to != owner, 'Error - approval to current owner');
        require(msg.sender == owner, 'Current caller is not the owner of the token');
        _tokenApprovals[tokenId] = _to;
        emit Approval(owner, _to, tokenId);
    }
}

错误发生在名为transferfrom的函数上，给了我一个错误，上面写着1：https://i.stack.imgur.com/m3Eio.png

请帮帮我，我被困在这里一个小时了，我不知道该怎么办。

Answer 1

这个代码是错误的：

function transferFrom(address _from, address _to, uint256 _tokenId) override public {
        require(msg.sender, _tokenId);
        transferFrom(_from, _to, _tokenId);
}

应：

function transferFrom(address _from, address _to, uint256 _tokenId) override public {
    require(msg.sender == _tokenOwner[_tokenId]," Error, not the owner"); 
    transferFrom(_from, _to, _tokenId);
}

在要求中应该有判断力，你可以将它改为其他的。