如何将 NFT 转移到另一个智能合约？

Question

我正在尝试设置一个托管合约，将存款作为 NFT 存入合约。我正在努力将 NFT 存入合约。

我从一个简单的 NFT 开始，它被铸造到带有 id 的地址。

contract MyEpicNFT is ERC721URIStorage {
  // Magic given to us by OpenZeppelin to help us keep track of tokenIds.
  using Counters for Counters.Counter;
  Counters.Counter private _tokenIds;

  // We need to pass the name of our NFTs token and its symbol.
  constructor() ERC721 ("SquareNFT", "SQUARE") {
    console.log("This is my NFT contract. Woah!");
    console.log(address(this));
  }

  // A function our user will hit to get their NFT.
  function makeNft() public {
    uint256 newItemId = _tokenIds.current();

    _safeMint(msg.sender, newItemId);

    _setTokenURI(newItemId, "https://jsonkeeper.com/b/1LHH");
    console.log("An NFT w/ ID %s has been minted to %s", newItemId, msg.sender);


    _tokenIds.increment();
  }
}

在这种情况下，已将 ID 为 0 的 NFT 铸造到合约的 msg.sender 中：0xdD870fA1b7C4700F2BD7f44238821C26f7392148

我知道现在我需要批准托管合同才能“花费”此令牌。要在 MyEpicNft 合约上执行此操作，我使用 MyEpicNft 的合约地址和铸造的 NFT 的 Id 调用批准函数。

console.log:
 This is my NFT contract. Woah!
 0x5fc7Dc95b4Bb48dbC9894fCaE417482cb8A6A45a

在我的例子中，我用 (0x5fc7Dc95b4Bb48dbC9894fCaE417482cb8A6A45a, 0) 调用批准 - 这似乎有效。现在我需要在 NftEscrow 合约中做的就是充值 NFT

我使用的 approve 函数来自 ERC721 库

approve(address to, uint256 tokenId)

有一个 depositNFT 函数获取 NFT 地址——在我们的例子中是 0x5fc7Dc95b4Bb48dbC9894fCaE417482cb8A6A45a 和 0。但是当我这样做时，我收到错误消息：

The transaction has been reverted to the initial state.
Reason provided by the contract: "ERC721: transfer caller is not owner nor approved".
Debug the transaction to get more information.


contract NftEscrow is IERC721Receiver {
    
    enum ProjectState {newEscrow, nftDeposited, cancelNFT, ethDeposited, canceledBeforeDelivery, deliveryInitiated, delivered}
    
    address payable public sellerAddress;
    address payable public buyerAddress;
    address public nftAddress;
    uint256 tokenID;
    bool buyerCancel = false;
    bool sellerCancel = false;
    ProjectState public projectState;

    receive() external payable {
    
     }

    constructor(){
        sellerAddress = payable(msg.sender);
        projectState = ProjectState.newEscrow;
    }
    
    function onERC721Received( address , address , uint256 , bytes calldata  ) public pure override returns (bytes4) {
        return this.onERC721Received.selector;
    }
    
    function depositNFT(address _NFTAddress, uint256 _TokenID) public onlySeller {
        nftAddress = _NFTAddress;
        tokenID = _TokenID;
        ERC721(nftAddress).safeTransferFrom(msg.sender, address(this), tokenID);
        projectState = ProjectState.nftDeposited;
    }

    function depositEth() public payable {
        buyerAddress = payable(msg.sender);
        projectState = ProjectState.ethDeposited;
    }

    function confirmDelivery()public payable  {
        ERC721(nftAddress).safeTransferFrom(address(this), buyerAddress, tokenID);
        sellerAddress.transfer(address(this).balance);
    }
    

    modifier onlySeller() {
        require(msg.sender == sellerAddress);
        _;
    }

}

不确定我做错了什么，并为此停留了一天。为什么我不能将 NFT 存入智能合约？

Answer 1

如果以下 none 为真，您的托管合同将恢复为 "ERC721: transfer caller is not owner nor approved"：

msg.sender 是合约的所有者
msg.sender 已为所有人批准
msg.sender 已被所有者批准使用该令牌

根据您的情况，我们选择第三个选项。

我们需要检查的是

你真的认可正确的地址吗？
审批功能恢复了吗？

托管合约调用NFT合约时

ERC721(nftAddress).safeTransferFrom(msg.sender, address(this), tokenID);

从NFT合约的角度来看，msg.sender就是托管合约。所以 99% 的问题出在你的审批流程上。请分享更多相关信息。

编辑：

我们正在尝试使以下条件为真，其中 spender 是托管合约的地址

return (spender == owner || isApprovedForAll(owner, spender) || getApproved(tokenId) == spender);

如果 getApproved 确实是 returns 合约地址，请尝试在您的 nft 合约中添加以下功能：

    /**
     * @dev Returns whether `spender` is allowed to manage `tokenId`.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function _isApprovedOrOwner(address spender, uint256 tokenId) internal view virtual override returns (bool) {
        require(_exists(tokenId), "ERC721: operator query for nonexistent token");
        address owner = ERC721.ownerOf(tokenId);
        console.log("spender %s", spender);
        console.log("getApproved %s", getApproved(tokenId);
        return (spender == owner || isApprovedForAll(owner, spender) || getApproved(tokenId) == spender);
    }

如何将 NFT 转移到另一个智能合约？

How to transfer a NFT to another smart contract?

ethereum

solidity

smartcontracts

remix