从 Web.js 连接到 Solidity 合约时地址无效

Question

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

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。我还通过 webpack 管理我的应用程序。

我在 Solidity 中编写了一个简单的合约(版本如下( - 并且可以从松露控制台毫无问题地连接到合约。

当通过一个简单的(对于这个演示(enroll(( 函数连接到合约时，我收到了一条Error: invalid address我现在以多种方式重写了代码，并且无论如何总是收到相同的错误。

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" - 当我第一次在我的 componentDidMount 函数中连接到 web3 时，以及通过 contract.defaults 函数连接到合约时，我都这样做了。到目前为止，这也没有产生任何影响。

任何关于我在这里做错了什么的想法将不胜感激！

相关版本如下

"web3"： "^1.2.1"，
"webpack"： "^4.20.2"，

"react"： "^16.2.0"，
"松露合同"： "^3.0.4"，

"solc"： "0.4.18"，

下面是尝试连接到合约的页面

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))
};

以下是坚固性合同的一部分

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，结果仍然是地址无效的错误。

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。如果要使用已部署的协定，请使用contract.at(<address of deployed contract>)。

例如，contract.deployed()用于测试，并在运行truffle test命令时返回迁移脚本中部署的协定。