React使用ref获得元素dom 刷新页面获得不到元素的宽高?

#1

下面是我的代码

  componentDidMount() {
    console.log('=================组件的宽高:', this.image.offsetWidth, this.image.offsetHeight);

    this.middle.style.width = `${this.contain.offsetWidth}px`;
    this.middle.style.height = `${this.contain.offsetWidth}px`;
    // 配置图片的宽高
    this.image.style.transform = `translate(0px,${parseInt((this.contain.offsetHeight - this.image.height) / 2, 10)}px)`;
  }

  render() {
    return (<div ref={((div) => { this.contain = div; })} className={styles.container}>
      <div id="cover-top" ref={(div) => { this.top = div; }} className={styles.coverTop}>
        <a href="javascript:">
          <input id="imageFile" name="image" type="file" accept="image/gif, image/jpeg, image/jpeg" />点击上传
        </a>
        <button >选择图片</button>
        <input id="x" name="x" />
        <input id="y" name="y" />
        <input id="width" name="width" />
        <input id="height" name="height" />
      </div>
      <div id="cover-middle" ref={(div) => { this.middle = div; }} className={styles.coverMiddle} />
      <div id="cover-down" ref={(div) => { this.down = div; }} className={styles.coverDown}>
        <button type="button" >获得裁剪参数</button><span id="params">12121</span>
      </div>
      <img id="image" ref={(image) => { this.image = image; }} className={styles.image} draggable="true" src={test} />
    </div>
    );
  }

除了第一次启动可以正常获得宽高之后,刷新浏览器等获得的宽高都不正常,高度一直就是0

#2

图片加载是异步的,你确实取到了image元素,但此时图片还未加载完全,所以高度是0

#3

是的,我已经发现了这个问题!