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

React原生web有一个useWindowDimensions钩子,可以使用:

    import { useWindowDimensions } from "react-native";
    const dimensions = useWindowDimensions()

其他回答

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);
}

通过在useCallback中包装getWindowDimensions函数,我对代码进行了轻微的更新

import { useCallback, useLayoutEffect, useState } from 'react';

export default function useWindowDimensions() {

    const hasWindow = typeof window !== 'undefined';

    const getWindowDimensions = useCallback(() => {
        const windowWidth = hasWindow ? window.innerWidth : null;
        const windowHeight = hasWindow ? window.innerHeight : null;

        return {
            windowWidth,
            windowHeight,
        };
    }, [hasWindow]);

    const [windowDimensions, setWindowDimensions] = useState(getWindowDimensions());

    useLayoutEffect(() => {
        if (hasWindow) {
            function handleResize() {
                setWindowDimensions(getWindowDimensions());
            }

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

    return windowDimensions;
}

我刚刚编辑了QoP当前的答案以支持SSR,并将其与Next.js (React 16.8.0+)一起使用:

/钩/ useWindowDimensions.js:

import { useState, useEffect } from 'react';

export default function useWindowDimensions() {

  const hasWindow = typeof window !== 'undefined';

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

  const [windowDimensions, setWindowDimensions] = useState(getWindowDimensions());

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

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

  return windowDimensions;
}

/ yourComponent.js:

import useWindowDimensions from './hooks/useWindowDimensions';

const Component = () => {
  const { height, width } = useWindowDimensions();
  /* you can also use default values or alias to use only one prop: */
  // const { height: windowHeight = 480 } useWindowDimensions();

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

我建议使用useSyncExternalStore

import { useSyncExternalStore } from "react";

const store = {
  size: {
    height: undefined,
    width: undefined
  }
};

export default function ChatIndicator() {
  const { height, width } = useSyncExternalStore(subscribe, getSnapshot);
  return (
    <h1>
      {width} {height}
    </h1>
  );
}

function getSnapshot() {
  if (
    store.size.height !== window.innerHeight ||
    store.size.width !== window.innerWidth
  ) {
    store.size = { height: window.innerHeight, width: window.innerWidth };
  }
  return store.size;
}

function subscribe(callback) {
  window.addEventListener("resize", callback);
  return () => {
    window.removeEventListener("resize", callback);
  };
}

如果你想试试:https://codesandbox.io/s/vibrant-antonelli-5cecpm

React原生web有一个useWindowDimensions钩子,可以使用:

    import { useWindowDimensions } from "react-native";
    const dimensions = useWindowDimensions()