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。
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
@speckledcarp的回答很好,但是如果你需要在多个组件中使用这个逻辑,那么可能会很乏味。您可以将其重构为HOC(高阶组件),以使此逻辑更易于重用。
withWindowDimensions.jsx
import React, { Component } from "react";
export default function withWindowDimensions(WrappedComponent) {
return class extends Component {
state = { width: 0, height: 0 };
componentDidMount() {
this.updateWindowDimensions();
window.addEventListener("resize", this.updateWindowDimensions);
}
componentWillUnmount() {
window.removeEventListener("resize", this.updateWindowDimensions);
}
updateWindowDimensions = () => {
this.setState({ width: window.innerWidth, height: window.innerHeight });
};
render() {
return (
<WrappedComponent
{...this.props}
windowWidth={this.state.width}
windowHeight={this.state.height}
isMobileSized={this.state.width < 700}
/>
);
}
};
}
然后在你的主组件中:
import withWindowDimensions from './withWindowDimensions.jsx';
class MyComponent extends Component {
render(){
if(this.props.isMobileSized) return <p>It's short</p>;
else return <p>It's not short</p>;
}
export default withWindowDimensions(MyComponent);
你也可以“堆叠”hoc,如果你有另一个你需要使用,例如withthrouter (withWindowDimensions(MyComponent))
编辑:我现在会用React钩子(上面的例子),因为它们解决了hoc和类的一些高级问题
其他回答
@speckledcarp和@Jamesl的回答都很精彩。然而,在我的例子中,我需要一个组件,其高度可以扩展整个窗口高度,在呈现时有条件....但是在render()中调用HOC会重新渲染整个子树。很糟糕。
另外,我对获取作为道具的值不感兴趣,但只是想要一个父div,将占据整个屏幕的高度(或宽度,或两者)。
所以我写了一个父组件,提供了一个完整的高度(和/或宽度)div。
一个用例:
class MyPage extends React.Component {
render() {
const { data, ...rest } = this.props
return data ? (
// My app uses templates which misbehave badly if you manually mess around with the container height, so leave the height alone here.
<div>Yay! render a page with some data. </div>
) : (
<FullArea vertical>
// You're now in a full height div, so containers will vertically justify properly
<GridContainer justify="center" alignItems="center" style={{ height: "inherit" }}>
<GridItem xs={12} sm={6}>
Page loading!
</GridItem>
</GridContainer>
</FullArea>
)
下面是这个组件:
import React, { Component } from 'react'
import PropTypes from 'prop-types'
class FullArea extends Component {
constructor(props) {
super(props)
this.state = {
width: 0,
height: 0,
}
this.getStyles = this.getStyles.bind(this)
this.updateWindowDimensions = this.updateWindowDimensions.bind(this)
}
componentDidMount() {
this.updateWindowDimensions()
window.addEventListener('resize', this.updateWindowDimensions)
}
componentWillUnmount() {
window.removeEventListener('resize', this.updateWindowDimensions)
}
getStyles(vertical, horizontal) {
const styles = {}
if (vertical) {
styles.height = `${this.state.height}px`
}
if (horizontal) {
styles.width = `${this.state.width}px`
}
return styles
}
updateWindowDimensions() {
this.setState({ width: window.innerWidth, height: window.innerHeight })
}
render() {
const { vertical, horizontal } = this.props
return (
<div style={this.getStyles(vertical, horizontal)} >
{this.props.children}
</div>
)
}
}
FullArea.defaultProps = {
horizontal: false,
vertical: false,
}
FullArea.propTypes = {
horizontal: PropTypes.bool,
vertical: PropTypes.bool,
}
export default FullArea
作为回答从:bren,但挂钩useEffect到[window.innerWidth]
const [dimension, updateDimention] = useState();
useEffect(() => {
window.addEventListener("resize", () => {
updateDimention({
...dimension,
width: window.innerWidth,
height: window.innerHeight
});
})
},[window.innerWidth]);
console.log(dimension);
你也可以试试这个:
constructor(props) {
super(props);
this.state = {height: props.height, width:props.width};
}
componentWillMount(){
console.log("WINDOW : ",window);
this.setState({height: window.innerHeight + 'px',width:window.innerWidth+'px'});
}
render() {
console.log("VIEW : ",this.state);
}
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>
);
}
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);
}