REACT:如何设置嵌套子对象的状态

import React, { Component } from 'react';

class MyComponent extends Component {
  constructor(props) {
    super(props);
    this.state = {
      parentObject: {
        childObject: {
          value: ''
        }
      }
    };
  }

  handleChange = (event) => {
    const { value } = event.target;
    this.setState(prevState => ({
      parentObject: {
        ...prevState.parentObject,
        childObject: {
          ...prevState.parentObject.childObject,
          value: value
        }
      }
    }));
  }

  render() {
    const { value } = this.state.parentObject.childObject;

    return (
      <div>
        <input type="text" value={value} onChange={this.handleChange} />
      </div>
    );
  }
}

export default MyComponent;