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
@foad abdollahi和@giovannipds答案的组合帮助我在Nextjs中使用useLayoutEffect自定义挂钩找到了一个解决方案。
function getWindowDimensions() {
const { innerWidth: width, innerHeight: height } = window;
return {
width,
height,
};
}
function useWindowDimensions() {
const [windowDimensions, setWindowDimensions] = useState(
getWindowDimensions()
);
useLayoutEffect(() => {
const isWindow = typeof window !== 'undefined';
function handleResize() {
setWindowDimensions(getWindowDimensions());
}
isWindow && window.addEventListener('resize', handleResize);
console.log(windowDimensions);
return () =>
isWindow && window.removeEventListener('resize', handleResize);
}, [windowDimensions]);
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
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}
// just use (useEffect). every change will be logged with current value
import React, { useEffect } from "react";
export function () {
useEffect(() => {
window.addEventListener('resize', () => {
const myWidth = window.innerWidth;
console.log('my width :::', myWidth)
})
},[window])
return (
<>
enter code here
</>
)
}
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;
}
