将this.props的值推送到子组件的状态

import React, { Component } from 'react';
import ChildComponent from './ChildComponent';

class ParentComponent extends Component {
  constructor(props) {
    super(props);
    this.state = {
      propValue: this.props.propValue // 将this.props的值赋给状态propValue
    };
  }

  updateState = (newValue) => {
    this.setState({ propValue: newValue }); // 更新状态propValue的值
  }

  render() {
    return (
      <div>
        <ChildComponent propValue={this.state.propValue} updateState={this.updateState} />
      </div>
    );
  }
}

export default ParentComponent;

import React, { Component } from 'react';

class ChildComponent extends Component {
  updateStateValue = () => {
    const newValue = this.props.propValue; // 获取父组件传递的props值
    this.props.updateState(newValue); // 调用父组件传递的方法，更新子组件的状态
  }

  render() {
    return (
      <div>
        <button onClick={this.updateStateValue}>更新状态值</button>
      </div>
    );
  }
}

export default ChildComponent;