从 Web.js 连接到 Solidity 合约时地址无效

Question

** 根据评论更新

当与合约交互并直接使用'合约地址：'直接从松露迁移输出的输出调用函数时，错误也是无效地址。

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Solidity 合约和 web3.js 的新手——（尽管我已经尝试让它工作好几个星期了！！）

我正在使用 react.js、truffle-contract 和 web3 创建一个 Dapp 并从 Ganache 连接到我的智能合约。我也在通过 webpack 管理我的应用程序。

我已经用 Solidity 编写了一个简单的合约（版本如下） - 并且可以从 truffle 控制台毫无问题地连接到合约。

当通过一个简单的（用于此演示的）enroll() 函数连接到合约时，我收到了一个 Error: invalid address 我现在已经以多种方式重写了代码，无论如何总是会收到相同的错误。

在这里查看了很多帖子后，我了解到这样做时一个相当常见的问题是我需要设置“默认值”——当我在 componentDidMount 函数中第一次连接到 web3 时，我已经这样做了通过 contract.defaults 函数连接到合约时也是如此。到目前为止，这也没有什么不同。

任何关于我在这里做错的想法将不胜感激！

相关版本如下

"web3": "^1.2.1", "webpack": "^4.20.2", “反应”：“^16.2.0”，

"truffle-contract": "^3.0.4",

"solc": "0.4.18",

下面是尝试连接合约的页面

    componentDidMount = () => {
    if(this.state.web3MetaON == false && this.state.accUnlock == false) {

      if (typeof web3 != 'undefined') {

        this.web3Provider = web3.currentProvider
        web3 = new Web3(web3.currentProvider)
        this.setState({web3MetaON: true})
        const accountID = web3.eth.accounts[0];
        web3.eth.defaultAccount = accountID;
        console.log('Window opening in older browser') 

        // check if accountID is available
        if(accountID !== null || accountID !== undefined) {
        this.setState({accUnlock: true})
        this.setState({account: accountID})

        this.loadDataContract(accountID)

    }
    else {
        console.log('Error on accessing account')
          this.setState({accUnlock: false})
    }
  }
    else {
          window.alert("Please connect to Metamask.")
          this.setState({web3MetaON: false})
          // ::TO-DO method to invoke retry after 2 seconds
        }
      }

      // Below loads web3 and sets state if browser
      // is and a modern ethereum browser 
      else if (window.ethereum && this.state.web3MetaON == false && this.state.accUnlock == false) {
        window.web3 = new Web3(ethereum)
        try {
          // Request account access if needed
          const accountID = ethereum.enable()
          web3.eth.sendTransaction({/* ... */})
          // setting state to accountID
          this.setState({account: accountID})
          this.setState({accUnlock: true})

          console.log('Window opening in modern browser')

        } catch (error) {
          console.log(error, 'Modern Browser failed')
          this.setState({web3MetaON: false})
        }
        console.log('Non-Ethereum browser detected. You should consider trying MetaMask!')
      }
    };

  loadDataContract = () =>  {
      const contract = TruffleContract(DataAccess)
      contract.setProvider(this.web3Provider)
      contract.defaults({from: this.web3Provider});

      // deploy contract
      contract.deployed().then((DataAccessInstance) => {
              this.DataAccessInstance = DataAccessInstance;
              DataAccessInstance.enroll()
                }).then(data => {
                window.alert("contract loaded.", data)

              }).catch(err => console.log("data load data this is ", err))
            };

下面是solidity合约的一部分

contract DataAccess {

    // This declares a new complex type which
    // will be used for variables
    // it represents a single usersData
    struct DataLocation {
        string ownerName;
        string ownerID;
        string url;
        string dateOfAccess;
        string timeOfAccess;
        uint accessCount;
        uint index;
    }

    struct Index {
        uint indexLocation;
    }

    // store Data that has a location
    mapping(address => DataLocation) private datastores;

    mapping (address => uint) private balances;

    // store datalocation Count
    uint public datalocationsCount;

    // userIndex stors location of pointers
    address[] public userIndex;

    // stored event
    event storedEvent (
        uint indexed _dataLocationId
    );

    // event for new data location 
    event LogNewData   (
        address indexed dataAddress, 
        string ownerName,
        string url,
        string ownerID,
        string dateOfAccess,
        string timeOfAccess,
       // uint accessCount,
        uint index);


    // event for new updated data  location 
    event LogUpdateData   (
        address indexed dataAddress,
        string ownerName,
        string url,
        string ownerID,
        string dateOfAccess,
        string timeOfAccess,
     //   uint accessCount,
        uint index);

    function enroll() public returns (uint){
      /* Set the sender's balance to 1000, return the sender's balance */
        address user = msg.sender;

        balances[user] = 1000; 
        return user.balance;
    }

当尝试根据反馈重写合约时，结果仍然是无效地址的错误。

  loadDataContract = () =>  {

      const contract = TruffleContract(DataAccess)
      contract.setProvider(this.web3Provider)
      contract.defaults({from: this.web3Provider});


      // initial function
      contract.at('0x8a4A12479486A427109e964e90CaEB5798C13A01').enroll().then((Output) => {
        this.setState({value: Output})
      }).catch(err => console.log("Enroll function error ", err))

    };

Answer 1

您应该使用contract.new() 来部署新合约。如果你想使用已经部署的合约，请使用contract.at(<address of deployed contract>)。

contract.deployed() 用于例如测试，当您运行truffle test 命令时，它会返回部署在迁移脚本中的合约。