问题描述
我正在使用Next.js和react-dates构建应用。
我有两个组件 DaterangePicker 组件和 DayPickerRangeController 组件。
我想在窗口的宽度大于1180px时呈现 DaterangePicker ,如果尺寸小于此值,我想呈现 DayPickerRangeController 。
代码如下:
windowSize > 1180 ?
<DaterangePicker
startDatePlaceholderText="Start"
startDate={startDate}
startDateId="startDate"
onDatesChange={handleOnDateChange}
endDate={endDate}
endDateId="endDate"
focusedInput={focus}
transitionDuration={0}
onFocusChange={(focusedInput) => {
if (!focusedInput) {
setFocus("startDate")
} else {
setFocus(focusedInput)
}
}}
/> :
<DayPickerRangeController
isOutsideRange={day => isInclusivelyBeforeDay(day,moment().add(-1,'days'))}
startDate={startDate}
onDatesChange={handleOnDateChange}
endDate={endDate}
focusedInput={focus}
onFocusChange={(focusedInput) => {
if (!focusedInput) {
setFocus("startDate")
} else {
setFocus(focusedInput)
}
}}
/>
}
我通常将带有窗口对象的react钩子用于检测窗口屏幕宽度,例如this
但是我发现在ssr时这种方法不可用,因为ssr渲染没有窗口对象。
是否有其他方法可以安全地获得窗口大小而与ssr无关?
解决方法
您可以通过添加以下代码来避免在ssr中调用检测功能:
// make sure your function is being called in client side only
if (typeof window !== 'undefined') {
// detect window screen width function
}
链接中的完整示例:
import { useState,useEffect } from 'react';
// Usage
function App() {
const size = useWindowSize();
return (
<div>
{size.width}px / {size.height}px
</div>
);
}
// Hook
function useWindowSize() {
// Initialize state with undefined width/height so server and client renders match
// Learn more here: https://joshwcomeau.com/react/the-perils-of-rehydration/
const [windowSize,setWindowSize] = useState({
width: undefined,height: undefined,});
useEffect(() => {
// only execute all the code below in client side
if (typeof window !== 'undefined') {
// Handler to call on window resize
function handleResize() {
// Set window width/height to state
setWindowSize({
width: window.innerWidth,height: window.innerHeight,});
}
// Add event listener
window.addEventListener("resize",handleResize);
// Call handler right away so state gets updated with initial window size
handleResize();
// Remove event listener on cleanup
return () => window.removeEventListener("resize",handleResize);
}
},[]); // Empty array ensures that effect is only run on mount
return windowSize;
}
,
Darryl RN提供了绝对正确的答案。我想说一句:您实际上不需要检查window
中是否存在useEffect
对象,因为useEffect
仅在客户端运行,而不在服务器端运行-端,window
对象始终在客户端可用。