智能合约:如何在React中获取实心函数的返回值？

Question

我希望在React中获得函数的返回，但我不知道为什么它不能工作(当我尝试console.log(this.state.data)时，我总是在控制台undefined中得到结果

我的contract.sol中的方法：

function data() public view returns (uint256){
        return choice1;
}

app.js：

class Pool1 extends Component {
    constructor(){
        super();
        this.state={
          web3: '',
          data: ''
        }

        this.getCote = this.getCote.bind(this);
      }

 getCote(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.data.call({from: accounts[0]})
        }).then((result) => {
          this.setState({
            data : result.c 
          })
        });
      })
  }

Answer 1

尝试添加methods in your call

return BettingInstance.methods.data.call({from: accounts[0]})