是否有一种方法可以访问组件中的节点？

import React, { createRef } from 'react';

class MyComponent extends React.Component {
  constructor(props) {
    super(props);
    this.myRef = createRef();
  }

  componentDidMount() {
    console.log(this.myRef.current); // 访问DOM节点
  }

  render() {
    return <div ref={this.myRef}>Hello, World!</div>;
  }
}

import React from 'react';

class MyComponent extends React.Component {
  constructor(props) {
    super(props);
    this.myRef = null;
  }

  componentDidMount() {
    console.log(this.myRef); // 访问DOM节点
  }

  render() {
    return <div ref={(node) => { this.myRef = node; }}>Hello, World!</div>;
  }
}

<template>
  <div>
    <div ref="myDiv">Hello, World!</div>
  </div>
</template>

<script>
export default {
  mounted() {
    console.log(this.$refs.myDiv); // 访问DOM节点
  }
}
</script>

<!-- app.component.html -->
<div #myDiv>Hello, World!</div>

// app.component.ts
import { Component, AfterViewInit, ViewChild, ElementRef } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent implements AfterViewInit {
  @ViewChild('myDiv') myDiv: ElementRef;

  ngAfterViewInit() {
    console.log(this.myDiv.nativeElement); // 访问DOM节点
  }
}

import React, { createRef } from 'react';

class MyComponent extends React.Component {
  constructor(props) {
    super(props);
    this.myRef = createRef();
  }

  componentDidMount() {
    if (this.myRef.current) {
      console.log(this.myRef.current); // 确保ref已定义
    }
  }

  render() {
    return <div ref={this.myRef}>Hello, World!</div>;
  }
}