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我试图使用 react 作为我的前端和solidity 作为我的后端来制作一个待办事项列表。我用 Truffle 和 Ganache 来测试它。我成功设置了私有区块链并从 Ganache 导入了多个帐户。但是，每当我在我的反应应用程序中使用 method.call() 时，它都会引发以下错误：

index.js:298 Uncaught (in promise) Error: Returned values aren't valid, did it run Out of Gas? 
You might also see this error if you are not using the correct ABI for the contract you are retrieving data from, requesting data from a block number that does not exist, or querying a node which is not fully synced.
    at ABICoder.push../node_modules/web3-eth-abi/lib/index.js.ABICoder.decodeParametersWith (index.js:298)
    at ABICoder.push../node_modules/web3-eth-abi/lib/index.js.ABICoder.decodeParameters (index.js:285)
    at Contract.push../node_modules/web3-eth-contract/lib/index.js.Contract._decodeMethodReturn (index.js:470)
    at Method.outputFormatter (index.js:760)
    at Method.push../node_modules/web3-core-method/lib/index.js.Method.formatOutput (index.js:147)
    at sendTxCallback (index.js:523)
    at cb (util.js:689)
    at Item.push../node_modules/process/browser.js.Item.run (browser.js:153)
    at drainQueue (browser.js:123)

我不知道我做错了什么。我检查了 abi 和合约地址，但它们似乎都是正确的。谁能告诉我导致错误的原因以及如何解决？这是我的可靠性和反应代码：

坚固性（合约）：

// SPDX-License-Identifier: MIT
pragma solidity >=0.6.0 <0.8.0;

pragma experimental ABIEncoderV2;

contract Todolist {
  string[][] lists;
  mapping (address => uint) public ownerToListId;
  mapping (address => bool) ownerHasList;

  function addToList(string calldata item) external{
    if (!ownerHasList[msg.sender]) {
      // newList = newList.push(item);
      lists.push([item]);
      ownerToListId[msg.sender] = lists.length - 1;
    } else {
      lists[ownerToListId[msg.sender]].push(item);
    }
  }

  function getList() external view returns(string[] memory) {
    return lists[ownerToListId[msg.sender]];
  }
}

反应（app.js）：

import React, { useState } from "react";
import Web3 from "web3";
import { todolistAbi } from "./abi/abis";
import "./App.css";

const web3 = new Web3(Web3.givenProvider);
const contractAddr = "0x75e4f59aBA61e780Accf573Ce632C2f31B534056";
const TodolistContract = new web3.eth.Contract(todolistAbi, contractAddr);

function App() {
  const [list, setList] = useState(["placeholder"]);
  // const [getNumber, setGetNumber] = useState(0x00);
  const [itemToAdd, setItemToAdd] = useState("");
  const getList = async () => {
    const list = await TodolistContract.methods.getList().call();
    console.log(list);
    setList(list.map((item) => <li>{item}</li>));
  };

  const addToList = async () => {
    const accounts = await window.ethereum.enable();
    const account = accounts[0];
    const gas = await TodolistContract.methods
      .addToList(itemToAdd)
      .estimateGas();
    await TodolistContract.methods
      .addToList(itemToAdd)
      .send({ from: account, gas });
    console.log("a");

    await getList();
  };

  return (
    <div className='App'>
      <header className='App-header'>
        <div>
          <ul>{list}</ul>
        </div>
        <br />
        <input type='text' onChange={(e) => setItemToAdd(e.target.value)} />
        <button onClick={addToList} type='button'>
          get the list!
        </button>
      </header>
    </div>
  );
}

export default App;

松露-config.js：

module.exports = {
  networks: {
    development: {
      host: "127.0.0.1", // Localhost (default: none)
      port: 7545, // Standard Ethereum port (default: none)
      network_id: "*", // Any network (default: none)
      from: "0xfbfaf75dea69c388f45d20d5aab7b947072d8416",
      gas: 18000000,
    },
  },

  mocha: {
  },

  compilers: {
    solc: {
      version: "0.6.0",
    },
  },
};

当我在反应中调用 getList 函数时出现错误...“const list = await TodolistContract.methods.getList().call();”

4

1 回答 1

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function getList() external view returns(string[] memory) {
    return lists[ownerToListId[msg.sender]];
  }

当您在反应端调用此函数时，您必须发送帐户和值。谁在调用这个函数？这个函数的调用者应该是经理，msg.sender。

于 2021-09-20T21:09:28.077 回答