Web3/JS:无法使用“.call()”读取“公共视图”函数，而调用其他函数(如call等…)工作精细

Question

我在这里张贴一个问题，我已经张贴在堆栈溢出之前，我意识到这个ethereum论坛。不确定这样做的礼仪，所以请告诉我是否应该删除堆栈溢出帖子(https://stackoverflow.com/questions/64909327/web3-js-unable-to-read-a-public-view-function-using-call-while-the-call)。

我正在为博彩智能合同编写一个小应用程序(使用react)，该应用程序受教程的启发(信用给：https://medium.com/coinmonks/create-a-sports-betting-dapp-on-the-ethereum-blockchain-part-1-1f69f908b939)。

这个教程很棒，但是我不得不在这里和那里做一些修改，因为这个教程有点过时(很明显，它是在Metamask使用.enable()提高安全性之前编写的)。但是总的来说，除了一件事之外，我设法使所有的东西都正常工作，而且我真的不明白为什么它不能工作(尝试了大量的修复，但是都没有起作用)。

在我的坚实契约中，我有一个非常简单的吸气器：

   // Getter for front end: amount of Bets in Pool1
   function AmountOne() public view returns(uint256){
       return totalBetOne;
   }

我很确定这个函数可以工作，因为我已经在Remix上测试过了

所以我的猜测是这个问题来自我的js脚本。同样奇怪的是，所有对其他函数的调用--它们都比较复杂--工作得很好，只有这个函数不能工作。现在，我真的是这门语言的初学者，所以我很难理解到底出了什么问题。任何帮助都将不胜感激。我的应用程序脚本如下：

 //constructor
     constructor(){
          super();
          this.state={
            web3: '',
            Amount: '',
            InputAmount: '',
            weiConversion: 1000000000000000000
          }
          this.getAmount = this.getAmount.bind(this);
          this.Bet = this.Bet.bind(this); 
        }
    
    
    //load web 3
    componentDidMount(){
        getWeb3.then(results => {
          /*After getting web3, we save the informations of the web3 user by
          editing the state variables of the component */
          results.web3.eth.getAccounts( (error,acc) => {
            //this.setState is used to edit the state variables
            this.setState({
              web3: results.web3
            })
          });
          //At the end of the first promise, we return the loaded web3
          return results.web3
        }).then(results => {
          //In the next promise, we pass web3 (in results) to the getAmount function
          this.getAmount(results)
        }).catch( () => {
          //If no web3 provider was found, log it in the console
          console.log('Error finding web3.')
        })
      }
    
      //Smart Contract function THAT DOES NOT WORK
  getAmount(web3){
    //Get the contract
    const contract = require('@truffle/contract');
    const Betting = contract(BettingContract);
    Betting.setProvider(web3.currentProvider);
    var BettingInstance;
    web3.eth.getAccounts((error, accounts) => {
        Betting.deployed().then((instance) => {
            //Instantiate the contract in a promise
            BettingInstance = instance
        }).then((result) => {
            //Calling the AmountOne function of the smart-contract
            return BettingInstance.AmountOne().call() // <-- issue: seems to return an empty value
        }).then((result) => {
            //Then the value returned is stored in the Amount state var.            
            this.setState({
                Amount : result.c              
            })
        });
    })
}
    
    
      //Smart Contract function THAT WORKS
      Bet(){
            //const contract = require('truffle-contract');
            const contract = require('@truffle/contract');
        const Betting = contract(BettingContract);
        Betting.setProvider(this.state.web3.currentProvider);
        var BettingInstance;
        this.state.web3.eth.getAccounts((error, accounts) => {
          Betting.deployed().then((instance) => {
            BettingInstance = instance
          }).then((result) => {
            // Get the value from the contract to prove it worked.
            return BettingInstance.bet(1, {from: accounts[0],
            value: this.state.InputAmount})
          }).catch(() => {
            console.log("Error with betting")
          })
        })
      }

如果错误来自我的getWeb3，下面是脚本：

import Web3 from 'web3'

let getWeb3 = new Promise(function(resolve, reject) {
  // Wait for loading completion before loading web3, to be sure it's
  // already injected
  window.addEventListener('load', function() {
    var results
    var web3 = window.web3
    
    // Pop-up to ask user to connect his Metamask
    // Modern DApp Browsers
    if (window.ethereum) {
      web3 = new Web3(window.ethereum);
      try { 
        window.ethereum.enable().then(function() {
            // User has allowed account access to DApp...
        });
      } catch(e) {
        // User has denied account access to DApp...
      }
    }
    // Legacy DApp Browsers
    else if (window.web3) {
      web3 = new Web3(window.web3.currentProvider);
    }
    // Non-DApp Browsers
    else {
      alert('You have to install MetaMask !');
    }

    // Connect to Metamask
    // Checking if Web3 has been injected by the browser MetaMask
    if (typeof web3 !== 'undefined') {
      // Use MetaMask's provider.
      web3 = new Web3(web3.currentProvider)
      results = {
        web3: web3
      }
      console.log('Injected web3 detected.');
      resolve(results)
    } else {
      // If no web3 is detected, then the local web3 provider is loaded.
      var provider = new Web3.providers.HttpProvider('http://127.0.0.1:9545')
      web3 = new Web3(provider)
      results = {
        web3: web3
      }
      console.log('No web3 instance injected, using Local web3.');
      resolve(results)
    }
  })
})
export default getWeb3

我没有包括所有的应用程序的其他部分，因为这篇文章已经够长了，但请问一下，如果你认为它可能相关的话，我很乐意把它们包括进去。

谢谢你的帮助!

Answer 1

好的，实际上这里的主要问题已经解决了：混乱控制台的问题:无法读取未定义的属性“调用”

我必须做一些其他的更改，以便粘贴在我的上下文中工作的代码，以防有人试图做这个教程，但无法使它工作：

getAmount(web3){
//Get the contract
const contract = require('@truffle/contract');
const Betting = contract(BettingContract);
Betting.setProvider(web3.currentProvider);
//var BettingInstance;
web3.eth.getAccounts((error, accounts) => {
Betting.deployed().then(function(instance) {
return instance.AmountTwo.call({from: accounts[0]})
}).then(function(AmountTwo){
const myres = AmountTwo.toString();
return myres
}).then((myres)=>{
this.setState({
Amount : myres/10**18
})
})
})
}