我正在使用 ReactJS 构建一个非常原始的测验应用程序，但无法更新Questions组件的状态。它的行为是将questions数组的正确索引呈现给 DOM 尽管this.state.questionNumber总是落后于DOM一步handleContinue()：

import React from "react"

export default class Questions extends React.Component {
  constructor() {
    super()
    this.state = {
      questionNumber: 1
    }
  }

  //when Continue button is clicked
  handleContinue() {
    if (this.state.questionNumber > 3) {
      this.props.unMount()
    } else {
      this.setState({
        questionNumber: this.state.questionNumber + 1
      })
      this.props.changeHeader("Question " + this.state.questionNumber)
    }
  }

  render() {
    const questions = ["blargh?", "blah blah blah?", "how many dogs?"]
    return (
      <div class="container-fluid text-center">
        <h1>{questions[this.state.questionNumber - 1]}</h1>
        <button type="button" class="btn btn-primary" onClick={this.handleContinue.bind(this)}>Continue</button>
      </div>
    )
  }
}