在 vs 代碼中用松露編譯 OpenZeppelin 導入的合約時出錯

Question

我正在運行一個在 CMD 中使用 truffle truffle init命令創建的松露項目。 然后我在同一個文件夾中創建一個帶有npx reate-react-app 。 我正在創建一個 NFT，所以我使用npm install @openzeppelin/contracts命令在我的反應應用程序中安裝了 OZ 合同。

現在，整個項目看起來像這樣。

根文件夾

Package.json

這是完整truffle-config.js

/**
 * Use this file to configure your truffle project. It's seeded with some
 * common settings for different networks and features like migrations,
 * compilation and testing. Uncomment the ones you need or modify
 * them to suit your project as necessary.
 *
 * More information about configuration can be found at:
 *
 * trufflesuite.com/docs/advanced/configuration
 *
 * To deploy via Infura you'll need a wallet provider (like @truffle/hdwallet-provider)
 * to sign your transactions before they're sent to a remote public node. Infura accounts
 * are available for free at: infura.io/register.
 *
 * You'll also need a mnemonic - the twelve word phrase the wallet uses to generate
 * public/private key pairs. If you're publishing your code to GitHub make sure you load this
 * phrase from a file you've .gitignored so it doesn't accidentally become public.
 *
 */

// const HDWalletProvider = require('@truffle/hdwallet-provider');
// const infuraKey = "fj4jll3k.....";
//
// const fs = require('fs');
// const mnemonic = fs.readFileSync(".secret").toString().trim();
const path = require("path");
module.exports = {
  contracts_build_directory: path.join(__dirname, "client/src/contracts"),
  /**
   * Networks define how you connect to your ethereum client and let you set the
   * defaults web3 uses to send transactions. If you don't specify one truffle
   * will spin up a development blockchain for you on port 9545 when you
   * run `develop` or `test`. You can ask a truffle command to use a specific
   * network from the command line, e.g
   *
   * $ truffle test --network <network-name>
   */

  networks: {
    // Useful for testing. The `development` name is special - truffle uses it by default
    // if it's defined here and no other network is specified at the command line.
    // You should run a client (like ganache-cli, geth or parity) in a separate terminal
    // tab if you use this network and you must also set the `host`, `port` and `network_id`
    // options below to some value.
    //
     development: {
      host: "127.0.0.1",     // Localhost (default: none)
      port: 7545,            // Standard Ethereum port (default: none)
      network_id: "*",       // Any network (default: none)
     },
    // Another network with more advanced options...
    // advanced: {
    // port: 8777,             // Custom port
    // network_id: 1342,       // Custom network
    // gas: 8500000,           // Gas sent with each transaction (default: ~6700000)
    // gasPrice: 20000000000,  // 20 gwei (in wei) (default: 100 gwei)
    // from: <address>,        // Account to send txs from (default: accounts[0])
    // websocket: true        // Enable EventEmitter interface for web3 (default: false)
    // },
    // Useful for deploying to a public network.
    // NB: It's important to wrap the provider as a function.
    // ropsten: {
    // provider: () => new HDWalletProvider(mnemonic, `https://ropsten.infura.io/v3/YOUR-PROJECT-ID`),
    // network_id: 3,       // Ropsten's id
    // gas: 5500000,        // Ropsten has a lower block limit than mainnet
    // confirmations: 2,    // # of confs to wait between deployments. (default: 0)
    // timeoutBlocks: 200,  // # of blocks before a deployment times out  (minimum/default: 50)
    // skipDryRun: true     // Skip dry run before migrations? (default: false for public nets )
    // },
    // Useful for private networks
    // private: {
    // provider: () => new HDWalletProvider(mnemonic, `https://network.io`),
    // network_id: 2111,   // This network is yours, in the cloud.
    // production: true    // Treats this network as if it was a public net. (default: false)
    // }
  },

  // Set default mocha options here, use special reporters etc.
  mocha: {
    // timeout: 100000
  },

  // Configure your compilers
  compilers: {
    solc: {
       version: "0.6.1",    // Fetch exact version from solc-bin (default: truffle's version)
      // docker: true,        // Use "0.5.1" you've installed locally with docker (default: false)
      // settings: {          // See the solidity docs for advice about optimization and evmVersion
      //  optimizer: {
      //    enabled: false,
      //    runs: 200
      //  },
      //  evmVersion: "byzantium"
      // }
    }
  },

  // Truffle DB is currently disabled by default; to enable it, change enabled: false to enabled: true
  //
  // Note: if you migrated your contracts prior to enabling this field in your Truffle project and want
  // those previously migrated contracts available in the .db directory, you will need to run the following:
  // $ truffle migrate --reset --compile-all

  db: {
    enabled: false
  }
};

在我的solidity合約文件中，路徑是C:\Dapp\Pet-Shop-IPFS-React\contracts\PetShop.sol ，我已經導入了安裝的 OZ ERC721 合約PetShop.js

pragma solidity >=0.4.22 <0.9.0;

import "@openzeppelin/contracts/token/ERC721/ERC721.sol";

contract PetShop is ERC721 {
    
      uint256 public tokenId;
      uint256 public prevOwnerTokenID;
      address public owner;
      
      mapping(uint256 => uint256) public priceMapping;
      mapping(uint256 => string) tokenIdToOffchainContentHash;
      
      event PetGenerated(address, uint256, uint256, string);
      event BuyPet(uint256, address, address);
      event SuccessfulEtherWithdrawal(uint256, address, bool);
      
       constructor()
        ERC721("ShanBuilders", "SBRS")
        {
            owner = msg.sender;
        }
     
       function generatePet(uint256 _petPrice, string memory contentHash) public returns(bool) {
         
         require(msg.sender != address(0), "Please! Check back! Registeration should not be from zero address");
         require(msg.sender == owner, "Only contract owner can generate more pets");
         
         tokenId++;
         require(tokenId <= 16, "More than 16 pets is not allowed");
         
         priceMapping[tokenId] = _petPrice;
         tokenIdToOffchainContentHash[tokenId] = contentHash;
         _mint(owner, tokenId);
         emit PetGenerated(owner, tokenId, _petPrice, contentHash);
         return true;
       }
       
       function checkPrice(uint256 _tokenId) public view returns(uint256) {
           return priceMapping[_tokenId];
       }
       
       function checkHashForAToken(uint256 _tokenId) public view returns(string memory) {
           return tokenIdToOffchainContentHash[_tokenId];
       }
       
       function buyPet(uint256 _tokenId) public payable returns(bool, string memory) {
           
           prevOwnerTokenID = _tokenId;
           address buyer = msg.sender;
           address _owner = ownerOf(prevOwnerTokenID);
           
           require(buyer != address(0), "Should not be zero address");
           require(_exists(prevOwnerTokenID), "Invalid property Id, not registered");
           require(msg.value == checkPrice(prevOwnerTokenID), "Please Send The Required Value");
           
           withDraw(msg.value);
            _transfer(_owner, buyer, prevOwnerTokenID);
           emit BuyPet(_tokenId, _owner, buyer);
           return (true, "Succesful");
       }
       
       function withDraw(uint256 _amount) internal returns(bool) {
       
        address _owner = ownerOf(prevOwnerTokenID);
        require(_amount > 0, "Amount must be valid");
        
        payable(_owner).transfer(_amount);
        emit SuccessfulEtherWithdrawal(_amount, _owner, true);
        return true;
    }
     
}

這是遷移

const PetShop = artifacts.require("PetShop");

module.exports = function (deployer) {
  deployer.deploy(PetShop);
};

Q在做完這一切之后出了點問題，我沒有注意到。 當我運行truffle compile它編譯失敗並拋出錯誤，

*** ParserError：找不到源“@openzeppelin/contracts/token/ERC721/ERC721.sol”：不支持文件導入回調***

我該如何解決這個問題，如果有人能幫助我理解這個錯誤的含義以及為什么會發生這種情況，那就太好了？

Answer 1

我已經通過以下方式解決了它，

@openzeppelin 庫。 我將它安裝在錯誤的位置，在反應中，它應該已經安裝在根文件夾中，在根文件夾中安裝 @openzeppelin 后，它會創建package-lock.json

編譯器版本作為@openzeppelin 的合約每次都使用最新的solidity 版本，現在它是0.8.0，而松露當前版本是5.2.0，而松露使用solidity 版本0.5.0 或介於0.5.5 之間的東西，我做了什么首先安裝npm install solc@0.8.0在根文件夾中安裝 solc@0.8.0 它會像這樣更新package-lock.json

"solc": {
      "version": "0.8.0",
      "resolved": "https://registry.npmjs.org/solc/-/solc-0.8.0.tgz",
      "integrity": "sha512-ypgvqYZhb/i5BM6cw9/5QkSlDJm/rLynsbWGP3kz6HeB6oNxPK6UMiB7jMr+tNVbQbBM/8l47vrI3XaDCHShjQ==",
      "requires": {
        "command-exists": "^1.2.8",
        "commander": "3.0.2",
        "follow-redirects": "^1.12.1",
        "fs-extra": "^0.30.0",
        "js-sha3": "0.8.0",
        "memorystream": "^0.3.1",
        "require-from-string": "^2.0.0",
        "semver": "^5.5.0",
        "tmp": "0.0.33"
      }

然后使用npm install -g truffle更新到0.5.3

我做的最后一步是使用以下內容更新truffle-config.js ：

compilers: {
    solc: {
       version: "0.8.0",    // Fetch exact version from solc-bin (default: truffle's version)
      // docker: true,        // Use "0.5.1" you've installed locally with docker (default: false)
      // settings: {          // See the solidity docs for advice about optimization and evmVersion
      //  optimizer: {
      //    enabled: false,
      //    runs: 200
      //  },
      //  evmVersion: "byzantium"
      // }
    }
  },

就是這樣，然后運行truffle compile ，如果它在 react/src 中創建一個contract文件夾並編譯成功，則不會出錯

const path = require("path");
module.exports = {
  contracts_build_directory: path.join(__dirname, "client/src/contracts"),
  /**
   * Networks define how you connect to your ethereum client and let you set the
   * defaults web3 uses to send transactions. If you don't specify one truffle
   * will spin up a development blockchain for you on port 9545 when you
   * run `develop` or `test`. You can ask a truffle command to use a specific
   * network from the command line, e.g
   *
   * $ truffle test --network <network-name>
   */