如何将NFT转移到另一个智能合同中？

Question

我正在尝试设置托管合同，该托管合同将押金作为NFT纳入合同。我正在努力将NFT存入合同中。

我首先要有一个简单的NFT，该NFT被用ID铸造到地址。

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，w/ id 0的NFT已被铸造给合同的味精。：0xDD870FA1B7C4700F2BD7F2BD7F444238821C26F7392148

我知道现在我需要允许批准托管合同来“支出”此tokken。为了在myepicnft合同上执行此操作，我将myepicnft的合同地址和铸造的NFT的ID称为批准功能。

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

就我而言，我将（0x5FC7DC95B4BB48DBC9894FCAE417482CB8A6A45A，0）称为批准。现在，我需要在NFTESCROW合同中要做的是存放NFT。

我使用的批准功能是来自ERC721 lib，

approve(address to, uint256 tokenId)

有一个reademnft函数获取NFT地址 - 在我们的情况下0x5fc7dc7dc95b4bb48db48dbc9894fcae417482cb8a6a45a和0

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);
        _;
    }

} 
 

。在这一天。为什么我不能将NFT存入智能合同？

Answer 1

您的托管合同将使用“ ERC721：转让呼叫者为所有者也不批准”如果以下各项为真：

1. msg.sender是合同的所有者
2. 。 sg.sender 已批准所有者
3. msg.sender在您的情况下，所有者批准了该令牌

，我们选择了第三种选项。

我们需要检查的是

1. 您是否真的批准了正确的地址？
2. 批准功能还原了吗？

当托管合同

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

以NFT合同的角度拨打NFT合同时，msg.sender是托管合同。因此，您的批准过程为99％。请分享有关此信息的更多信息。

编辑：

我们正在尝试使以下条件正确，其中spender是托管合同的地址，

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

如果签名确实是返回合同地址，请尝试在您的NFT合同中添加以下功能：

    /**
     * @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);
    }