contract.methods.balance不是一个函数

Question

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Smart contract :

// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.0;

contract Booster {
  address owner;
  mapping(address => uint256) public accountBalances;

  event PaymentAdded(address user, uint256 amount, uint256 timestamp);

modifier onlyOwner(){
    require(msg.sender!=owner,"only owner can call this");
    _;
}
  constructor() {
    owner = msg.sender;
  }


  function fund() public payable{
    require (msg.value > 0, "Empty transact");
    //payable(address(this)).transfer(msg.value);
    accountBalances[msg.sender]=msg.value;
    emit PaymentAdded(msg.sender, msg.value, block.timestamp);

  }
  function withdraw() public payable  {
    payable(owner).transfer(address(this).balance);
  }

  function balance() public view returns (uint256){
    return payable(address(this)).balance;
  }
}

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connection:

if(typeof window.ethereum !== 'undefined') {
 await connectwallet();
 //const provider = new ethers.providers.Web3Provider(window.ethereum); 
 console.log("abi",ContractAbi);
 const contract = new web3provide.eth.Contract( ContractAbi, ContractAddress,{gasPrice: '20000000000'});
 console.log(contract.methods);
 await contract.methods.balance().call.then(function(bal){
   setBalance(bal);
 })
}  }

​

当通过web3.0从前端连接智能契约时，会显示零方法，但在智能contracts.First智能契约中有方法，在react中有第二个连接

Answer 1

这可能是由于ABI接口的缘故，对于您的合同来说，这个接口应该是：

const CONTRACT_ABI = [
  {
    inputs: [],
    stateMutability: "nonpayable",
    type: "constructor",
  },
  {
    anonymous: false,
    inputs: [
      {
        indexed: false,
        internalType: "address",
        name: "user",
        type: "address",
      },
      {
        indexed: false,
        internalType: "uint256",
        name: "amount",
        type: "uint256",
      },
      {
        indexed: false,
        internalType: "uint256",
        name: "timestamp",
        type: "uint256",
      },
    ],
    name: "PaymentAdded",
    type: "event",
  },
  {
    inputs: [
      {
        internalType: "address",
        name: "",
        type: "address",
      },
    ],
    name: "accountBalances",
    outputs: [
      {
        internalType: "uint256",
        name: "",
        type: "uint256",
      },
    ],
    stateMutability: "view",
    type: "function",
  },
  {
    inputs: [],
    name: "balance",
    outputs: [
      {
        internalType: "uint256",
        name: "",
        type: "uint256",
      },
    ],
    stateMutability: "view",
    type: "function",
  },
  {
    inputs: [],
    name: "fund",
    outputs: [],
    stateMutability: "payable",
    type: "function",
  },
  {
    inputs: [],
    name: "withdraw",
    outputs: [],
    stateMutability: "payable",
    type: "function",
  },
]

然后，如果您使用的是web3.js：

const Web3 = require("web3")
const web3 = new Web3(window.ethereum)

const contract = new web3.eth.Contract(CONTRACT_ABI, CONTRACT_ADDRESS)
console.log(contract.methods)

// {
//   accountBalances: [Function: bound _createTxObject],
//   '0x6ff96d17': [Function: bound _createTxObject],
//   'accountBalances(address)': [Function: bound _createTxObject],
//   balance: [Function: bound _createTxObject],
//   '0xb69ef8a8': [Function: bound _createTxObject],
//   'balance()': [Function: bound _createTxObject],
//   fund: [Function: bound _createTxObject],
//   '0xb60d4288': [Function: bound _createTxObject],
//   'fund()': [Function: bound _createTxObject],
//   withdraw: [Function: bound _createTxObject],
//   '0x3ccfd60b': [Function: bound _createTxObject],
//   'withdraw()': [Function: bound _createTxObject]
// }

或者，如果您使用的是ethers.js：

const { ethers } = require("ethers")
const provider = new ethers.providers.Web3Provider(window.ethereum)

const contract = new ethers.Contract(CONTRACT_ADDRESS, CONTRACT_ABI, provider)
console.log(contract.functions)

// {
//   'accountBalances(address)': [Function (anonymous)],
//   'balance()': [Function (anonymous)],
//   'fund()': [Function (anonymous)],
//   'withdraw()': [Function (anonymous)],
//   accountBalances: [Function (anonymous)],
//   balance: [Function (anonymous)],
//   fund: [Function (anonymous)],
//   withdraw: [Function (anonymous)]
// }