仅在一个变量上使用setState

import React, { Component } from 'react';

class MyComponent extends Component {
  constructor(props) {
    super(props);
    this.state = {
      count: 0,
    };
  }

  handleClick() {
    // 使用setState更新count的值
    this.setState({
      count: this.state.count + 1,
    }, () => {
      // 在回调函数中可以执行某些操作
      console.log('count updated: ', this.state.count);
    });
  }

  render() {
    return (
      <div>
        <h1>Count: {this.state.count}</h1>
        <button onClick={() => this.handleClick()}>Increase Count</button>
      </div>
    );
  }
}

export default MyComponent;