如何在ReactJS中获得视口高度?在正常的JavaScript中使用

window.innerHeight()

但是使用ReactJS,我不确定如何获得这些信息。我的理解是

ReactDOM.findDomNode()

仅适用于已创建的组件。然而,对于文档或body元素,情况并非如此,它们可以为我提供窗口的高度。


当前回答

你可以像这样创建自定义钩子:

import { useEffect, useState } from "react";
import { debounce } from "lodash";

const getWindowDimensions = () => {
  const { innerWidth: width, innerHeight: height } = window;
  return { width, height };
};

export function useWindowSize(delay = 0) {
  const [windowDimensions, setWindowDimensions] = useState(
    getWindowDimensions()
  );

  useEffect(() => {
    function handleResize() {
      setWindowDimensions(getWindowDimensions());
    }
    const debouncedHandleResize = debounce(handleResize, delay);
    window.addEventListener("resize", debouncedHandleResize);
    return () => window.removeEventListener("resize", debouncedHandleResize);
  }, [delay]);

  return windowDimensions;
}

其他回答

有一个包有93.000+下载,名为useWindowSize()

NPM I @react-hook/window-size

import {
  useWindowSize,
  useWindowWidth,
  useWindowHeight,
} from '@react-hook/window-size'

const Component = (props) => {
  const [width, height] = useWindowSize()
  const onlyWidth = useWindowWidth()
  const onlyHeight = useWindowHeight()
...
}

docs

保持当前尺寸状态的简单方法,即使在窗口调整大小后:

//set up defaults on page mount
componentDidMount() {
  this.state = { width: 0, height: 0 };
  this.getDimensions(); 

  //add dimensions listener for window resizing
  window.addEventListener('resize', this.getDimensions); 
}

//remove listener on page exit
componentWillUnmount() {
  window.removeEventListener('resize', this.getDimensions); 
}

//actually set the state to the window dimensions
getDimensions = () => {
  this.setState({ width: window.innerWidth, height: window.innerHeight });
  console.log(this.state);
}

添加这个是为了多样性和干净的方法。

此代码使用函数式方法。我已经使用onresize而不是addEventListener,如在其他答案中提到的。

import { useState, useEffect } from "react";

export default function App() {
  const [size, setSize] = useState({
    x: window.innerWidth,
    y: window.innerHeight
  });
  const updateSize = () =>
    setSize({
      x: window.innerWidth,
      y: window.innerHeight
    });
  useEffect(() => (window.onresize = updateSize), []);
  return (
    <>
      <p>width is : {size.x}</p>
      <p>height is : {size.y}</p>
    </>
  );
}

使用钩子(React 16.8.0+)

创建一个useWindowDimensions钩子。

import { useState, useEffect } from 'react';

function getWindowDimensions() {
  const { innerWidth: width, innerHeight: height } = window;
  return {
    width,
    height
  };
}

export default function useWindowDimensions() {
  const [windowDimensions, setWindowDimensions] = useState(getWindowDimensions());

  useEffect(() => {
    function handleResize() {
      setWindowDimensions(getWindowDimensions());
    }

    window.addEventListener('resize', handleResize);
    return () => window.removeEventListener('resize', handleResize);
  }, []);

  return windowDimensions;
}

之后你就可以像这样在元件中使用它了

const Component = () => {
  const { height, width } = useWindowDimensions();

  return (
    <div>
      width: {width} ~ height: {height}
    </div>
  );
}

工作示例

原来的答案

在React中也是一样的,你可以使用window。innerHeight来获取当前视口的高度。

正如你在这里看到的

class AppComponent extends React.Component {

  constructor(props) {
    super(props);
    this.state = {height: props.height};
  }

  componentWillMount(){
    this.setState({height: window.innerHeight + 'px'});
  }

  render() {
    // render your component...
  }
}

设置道具

AppComponent.propTypes = {
 height:React.PropTypes.string
};

AppComponent.defaultProps = {
 height:'500px'
};

视口高度现在可用{this.state。渲染模板中的Height}