Polygon测试网NFT合约部署失败：执行回滚错误求助

问题描述 #

在Polygon测试网部署ERC721 NFT合约时交易失败，报错信息：

Warning! Error encountered during contract execution [execution reverted]

附上合约代码如下：

pragma solidity >=0.7.0 <0.9.0;

import "@openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

contract NFT is ERC721Enumerable, Ownable {
  using Strings for uint256;

  string public baseURI;
  string public baseExtension = ".json";
  uint256 public cost = 0.05 ether;
  uint256 public maxSupply = 300;
  uint256 public maxMintAmount = 10;
  bool public paused = false;
  mapping(address => bool) public whitelisted;

  constructor(
    string memory _name,
    string memory _symbol,
    string memory _initBaseURI
  ) ERC721(_name, _symbol) {
    setBaseURI(_initBaseURI);
    mint(msg.sender, 20);
  }
  
  // internal
  function _baseURI() internal view virtual override returns (string memory) {
    return baseURI;
  }

  // public
  function mint(address _to, uint256 _mintAmount) public payable {
    uint256 supply = totalSupply();
    require(!paused);
    require(_mintAmount > 0);
    require(_mintAmount <= maxMintAmount);
    require(supply + _mintAmount <= maxSupply);

    if (msg.sender != owner()) {
        if(whitelisted[msg.sender] != true) {
          require(msg.value >= cost * _mintAmount);
        }
    }

    for (uint256 i = 1; i <= _mintAmount; i++) {
      _safeMint(_to, supply + i);
    }
  }

  function walletOfOwner(address _owner)
    public
    view
    returns (uint256[] memory)
  {
    uint256 ownerTokenCount = balanceOf(_owner);
    uint256[] memory tokenIds = new uint256[](ownerTokenCount);
    for (uint256 i; i < ownerTokenCount; i++) {
      tokenIds[i] = tokenOfOwnerByIndex(_owner, i);
    }
    return tokenIds;
  }

  function tokenURI(uint256 tokenId)
    public
    view
    virtual
    override
    returns (string memory)
  {
    require(
      _exists(tokenId),
      "ERC721Metadata: URI query for nonexistent token"
    );

    string memory currentBaseURI = _baseURI();
    return bytes(currentBaseURI).length > 0
        ? string(abi.encodePacked(currentBaseURI, tokenId.toString(), baseExtension))
        : "";
  }

  //only owner
  function setCost(uint256 _newCost) public onlyOwner {
    cost = _newCost;
  }

  function setmaxMintAmount(uint256 _newmaxMintAmount) public onlyOwner {
    maxMintAmount = _newmaxMintAmount;
  }

  function setBaseURI(string memory _newBaseURI) public onlyOwner {
    baseURI = _newBaseURI;
  }

  function setBaseExtension(string memory _newBaseExtension) public onlyOwner {
    baseExtension = _newBaseExtension;
  }

  function pause(bool _state) public onlyOwner {
    paused = _state;
  }
 
 function whitelistUser(address _user) public onlyOwner {
    whitelisted[_user] = true;
  }
 
  function removeWhitelistUser(address _user) public onlyOwner {
    whitelisted[_user] = false;
  }

  function withdraw() public payable onlyOwner {
    (bool hs, ) = payable(0x985C134D876439d92De8DD3c6e7d66dd420D481a).call{value: address(this).balance * 5 / 100}("");
    require(hs);

    (bool os, ) = payable(owner()).call{value: address(this).balance}("");
    require(os);
  }
}

核心问题与解决方案 #

1. 构造函数铸造量超出限制（最可能触发报错的原因） #

合约中maxMintAmount默认值为10，但构造函数里直接调用mint(msg.sender, 20)，触发了mint函数中的require(_mintAmount <= maxMintAmount)校验，导致部署时交易回滚。

修复方案：

• 方案一：调整构造函数中的铸造数量，不超过maxMintAmount：

  constructor(
      string memory _name,
      string memory _symbol,
      string memory _initBaseURI
  ) ERC721(_name, _symbol) {
      setBaseURI(_initBaseURI);
      mint(msg.sender, 10); // 修改为10或更小
  }
  

• 方案二：先在构造函数中临时调整maxMintAmount，再执行铸造：

  constructor(
      string memory _name,
      string memory _symbol,
      string memory _initBaseURI
  ) ERC721(_name, _symbol) {
      setBaseURI(_initBaseURI);
      maxMintAmount = 20; // 临时设置最大铸造量为20
      mint(msg.sender, 20);
      maxMintAmount = 10; // 可选：铸造完成后改回原限制
  }
  

2. OpenZeppelin合约版本与编译器不兼容 #

合约pragma声明为>=0.7.0 <0.9.0，若使用的OpenZeppelin合约版本（如4.x+）依赖Solidity 0.8.x语法（如自定义错误），会导致编译或部署失败。

修复方案：

• 若使用Solidity 0.7.x编译器，安装3.x版本的OpenZeppelin合约：

  npm install @openzeppelin/contracts@3.4.0
  

• 若使用Solidity 0.8.x编译器，将pragma调整为>=0.8.0 <0.9.0，并安装4.x版本的OpenZeppelin合约：

  npm install @openzeppelin/contracts@4.9.3
  

3. 部署参数缺失或格式错误 #

构造函数需要传入_name、_symbol、_initBaseURI三个字符串参数，若部署时未正确传入（如为空字符串或格式错误），也可能触发异常。

修复方案：部署时确保传入合法参数，例如：

• _name："MyTestNFT"
• _symbol："MTNFT"
• _initBaseURI："ipfs://QmXYZ123..."（需确保元数据地址格式正确）

内容的提问来源于stack exchange，提问作者Mohsin Shaikh