ReactJS - 获取元素的高度

小编典典

ReactJS - 获取元素的高度

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React 渲染元素后如何获取元素的高度？

HTML

<div id="container">
<!-- This element's contents will be replaced with your component. -->
<p>
jnknwqkjnkj<br>
jhiwhiw (this is 36px height)
</p>
</div>

反应JS

var DivSize = React.createClass({

  render: function() {
    let elHeight = document.getElementById('container').clientHeight
    return <div className="test">Size: <b>{elHeight}px</b> but it should be 18px after the render</div>;
  }
});

ReactDOM.render(
  <DivSize />,
  document.getElementById('container')
);

结果

Size: 36px but it should be 18px after the render

它在渲染之前计算容器高度（36px）。我想在渲染后获得高度。在这种情况下，正确的结果应该是
18px。jsfiddle

阅读 161

2022-07-31

共1个答案

小编典典

看到这个小提琴（实际上更新了你的）

您需要挂钩componentDidMount在渲染方法之后运行的哪个。在那里，您可以获得元素的实际高度。

var DivSize = React.createClass({
    getInitialState() {
    return { state: 0 };
  },

  componentDidMount() {
    const height = document.getElementById('container').clientHeight;
    this.setState({ height });
  },

  render: function() {
    return (
        <div className="test">
        Size: <b>{this.state.height}px</b> but it should be 18px after the render
      </div>
    );
  }
});

ReactDOM.render(
  <DivSize />,
  document.getElementById('container')
);



<script src="https://facebook.github.io/react/js/jsfiddle-integration-babel.js"></script>

<div id="container">
<p>
jnknwqkjnkj<br>
jhiwhiw (this is 36px height)
</p>
    <!-- This element's contents will be replaced with your component. -->
</div>

2022-07-31