首页 > 解决方案 > 如何使用反应钩子检测 Next.js SSR 中的窗口大小?

问题描述

我正在使用 Next.js 和react-dates构建一个应用程序。

我有两个组件DateRangePicker组件和DayPickerRangeController组件。

当窗口的宽度大于 1180px 时,我想渲染DateRangePicker,如果尺寸小于这个,我想渲染DayPickerRangeController

这是代码:

      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)
                 }
               }}
              /> 
          }

我通常使用带有窗口对象的反应钩子来检测这样的窗口屏幕宽度

但是我发现这种方式在ssr的时候不可用,因为ssr渲染没有window对象。

无论ssr如何,有没有另一种方法可以安全地获取窗口大小?

标签: reactjsnext.jsserver-side-renderingreact-dates

解决方案


您可以通过添加以下代码来避免在 ssr 中调用您的检测函数:

// make sure your function is being called in client side only
if (typeof window !== 'undefined') {
  // detect window screen width function
}

您的链接中的完整示例:

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;
}

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