调用恢复异常

Question

在学习 Solidity 教程后，我正在前端工作，但最终遇到了这个 error

它不会让我获取问候语但我可以设置问候语除获取问候语外其他一切都有效，即使我将问候语设置为其他我不能看到它也不会让我看到它在控制台中看到它只是这里的错误是 Solidity tutorial

这是我的代码

pragma solidity ^0.8.4;

import "hardhat/console.sol";


contract Greeter {
  string greeting;

  constructor(string memory _greeting) {
    console.log("Deploying a Greeter with greeting:", _greeting);
    greeting = _greeting;
  }

  function greet() public view returns (string memory) {
    return greeting;
  }

  function setGreeting(string memory _greeting) public {
    console.log("Changing greeting from '%s' to '%s'", greeting, _greeting);
    greeting = _greeting;
  }
}

这是我的反应代码：

import './App.css';
import { useState } from 'react';
import { ethers } from 'ethers'
import Greeter from './artifacts/contracts/Greeter.sol/Greeter.json'

// Update with the contract address logged out to the CLI when it was deployed 
const greeterAddress = "0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266"

function App() {
  // store greeting in local state
  const [greeting, setGreetingValue] = useState()

  // request access to the user's MetaMask account
  async function requestAccount() {
    await window.ethereum.request({ method: 'eth_requestAccounts' });
  }

  // call the smart contract, read the current greeting value
  async function fetchGreeting() {
    if (typeof window.ethereum !== 'undefined') {
      const provider = new ethers.providers.Web3Provider(window.ethereum)
      const contract = new ethers.Contract(greeterAddress, Greeter.abi, provider)
      try {
        const data = await contract.greet()
        console.log('data: ', data)
      } catch (err) {
        console.log("Error: ", err)
      }
    }    
  }

  // call the smart contract, send an update
  async function setGreeting() {
    if (!greeting) return
    if (typeof window.ethereum !== 'undefined') {
      await requestAccount()
      const provider = new ethers.providers.Web3Provider(window.ethereum);
      const signer = provider.getSigner()
      const contract = new ethers.Contract(greeterAddress, Greeter.abi, signer)
      const transaction = await contract.setGreeting(greeting)
      await transaction.wait()
      fetchGreeting()
    }
  }

  return (
    <div className="App">
      <header className="App-header">
        <button onClick={fetchGreeting}>Fetch Greeting</button>
        <button onClick={setGreeting}>Set Greeting</button>
        <input onChange={e => setGreetingValue(e.target.value)} placeholder="Set greeting" />
      </header>
    </div>
  );
}

export default App;

任何建议都会有所帮助，谢谢

Answer 1

您需要插入属性值

value = {greeting}

在输入中：

  <input onChange={e => setGreetingValue(e.target.value)} 
        placeholder="Introduce uno nuevo" 
        value={greeting}
        />

同样用两个引号初始化useState():

const [greeting, setGreetingValue] = useState ('')

你现在可能会遇到元掩码随机数的问题，它会告诉你它太高了，就像这样的消息错误：

Nonce too high. Expected nonce to be 1 but got 2

您将在 metamask 中重置帐户，或导入一个新帐户。

调用恢复异常

Call Revert Exception

javascript

reactjs

blockchain

react-native

solidity