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
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>
);
}
其他回答
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;
}
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
我发现了一个简单的组合QoP和speckledcarp的答案，使用React Hooks和调整大小功能，代码行数略少:
const [width, setWidth] = useState(window.innerWidth);
const [height, setHeight] = useState(window.innerHeight);
const updateDimensions = () => {
setWidth(window.innerWidth);
setHeight(window.innerHeight);
}
useEffect(() => {
window.addEventListener("resize", updateDimensions);
return () => window.removeEventListener("resize", updateDimensions);
}, []);
哦，是的，确保resize事件是双引号，而不是单引号。这一点让我有点不安;)
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>
);
}
