Javascript React中是否有更新DOM的特殊方法？

您好，我正在React中制作一个flashcard应用程序，我正在尝试在两张卡之间切换，但在我切换卡之前，它们不会更新

我尝试将索引currentCard设置为state而不是全局，但在实现时遇到了一些问题。我也尝试过这个.forceUpdate，但结果都是未定义的

import React from 'react';
import './App.css';
import 'bootstrap/dist/css/bootstrap.min.css';

// variables
let currentCard = 0;

这是我获得卡片的地方：

const mockData = [
  {
    front: "Hello",
    back: "Dobrý den"
  },
  {
    front: "How are you?",
    back: "Jak se máš?"
  },
  {
    front: "I'm fine",
    back: "Mám se dobře"
  }

];

class LeftArrow extends React.Component {
  constructor(props){
    super(props);
    this.state = {isClicked: false};
  }

  render(){
    //checks it so it can't be less than zero
    return(
      <button
      className="btn btn-primary"
      onClick={() => this.props.onCardChange('LEFT')}
      >&lt;</button>
    )
  }
}

class RightArrow extends React.Component {
  constructor(props){
    super(props);
    this.state = {isClicked: false};
  }

  render(){
    // checks it so it isn't more than the length of array
    // checks if card has
    return(
      <button
      className="btn btn-primary"
      onClick={() => this.props.onCardChange('RIGHT')}
      >
      &gt;
      </button>
    )
  }
}

class Card extends React.Component {
  constructor(props){
    super(props);
    // helps toggle between the front face and the back
    this.state = {
      isFront: true,
    };
  } 

---

您必须将mockData和currentCard置于卡组件的状态，handleCardChange应使用此.setState{}更新状态

使用设置状态

this.setState({someState: "someNewState"})

---

大家好，欢迎来到Stack Overflow！你能把你的帖子缩小一点，只包含与你的问题相关的代码吗？对于许多人来说，这可能有点难以承受…setState使用setState组件方法更新组件的状态数据。以这种方式更新组件的状态将重新呈现该组件的DOM。

const mockData = [
  {
    front: "Hello",
    back: "Dobrý den"
  },
  {
    front: "How are you?",
    back: "Jak se máš?"
  },
  {
    front: "I'm fine",
    back: "Mám se dobře"
  }
];

class Card extends React.Component {
  constructor(props) {
    super(props);
    // helps toggle between the front face and the back
    this.state = {
      isFront: true
      currentCard: 0,
      mockData,
    };
  }

this.setState({someState: "someNewState"})