如何在 ERC721 合约中调用 ERC20 合约函数

Question

我想要完成的是从 ERC721 合约调用 ERC20 合约中定义的函数，如下所示，特别是 ERC20 合约中的 transferFrom 函数在 ERC721 中的同一函数内。

这不会编译。 它最终的作用是，每次发生 erc721 NFT 转让时，版税都会以 erc20 代币的形式转让给创作者。

import "./myToken.sol" as erc20contract //This is my ERC20 contract

contract ERC721 is ERC721Interface, myToken {
    function transferFrom(address _from, address _to, uint256 _tokenId) public payable {

        address addr_owner = ownerOf(_tokenId);

        require(
            addr_owner == _from,
            "_from is NOT the owner of the token"
        );

        require(
            _to != address(0),
            "Transfer _to address 0x0"
        );

        address addr_allowed = allowance[_tokenId];
        bool isOp = operators[addr_owner][msg.sender];

        require(
            addr_owner == msg.sender || addr_allowed == msg.sender || isOp,
            "msg.sender does not have transferable token"
        );


        //transfer : change the owner of the token
        tokenOwners[_tokenId] = _to;
        balances[_from] = balances[_from].sub(1);
        balances[_to] = balances[_to].add(1);

        //reset approved address
        if (allowance[_tokenId] != address(0)) {
            delete allowance[_tokenId];
        }

        erc20contract.transferFrom(_to, nftInfo[_from].creator, 10); // This is what I'd like to achieve
        {
        emit Transfer(_from, _to, _tokenId);
    }
}

Answer 1

编辑：我刚刚注意到您的合同似乎同时实现了ERC721 和ERC20 标准。您将need to decide on one，但使用组合（如下所示）可能足以提供您所追求的所有必要功能。

---

除非我遗漏了什么，否则您似乎只是缺少 ERC20 代币的实际实例。例如：

contract YourToken is ERC721 {
  ERC20 private immutable token;

  constructor(ERC20 t) {
    token = t;
  }

  function transferFrom(address _from, address _to, uint256 _tokenId) public payable {
    // Your code here.
    token.transferFrom(_from, _to, 10);
  }
}