useRef 抛出不可分配给类型 LegacyRef<Slider> |不明确的

Question

我正在使用 react-slick-slider，我想要实现的是制作自定义箭头。
所以代码看起来像这样：

const FeedbackSlider = () => {
const [isLargeScreen] = useMediaQuery("(min-width: 1050px)")

const sliderRef = useRef<Slider>()

const prev = () => {
    sliderRef.current?.slickPrev()
}
const next = () => {
    sliderRef.current?.slickNext()
}
const settings = {
    dots: false,
    infinite: true,
    speed: 500,
    slidesToShow: (isLargeScreen ? 2 : 1),
    slidesToScroll: 1,
    prevArrow: (isLargeScreen && <PrevArrow />),
    nextArrow: (isLargeScreen && <NextArrow />)
};
return (
    <Box px={['2', '4', '8', '16']} mx='auto' pt='12'>
        <Slider ref={sliderRef} {...settings}>
           // slider cards...
        </Slider>
        {!isLargeScreen && (
            <Flex alignItems='center' w='5xs' justifyContent='space-between' mx='auto' my='5'>
                <PrevArrow onClick={prev} />
                <NextArrow onClick={next} />
            </Flex>)}
    </Box >)

用作类型的 Slider 是从我正在使用的 react-slick 导入的 Slider 组件我只在 VScode 中收到错误代码在浏览器中正常工作：

No overload matches this call. Overload 1 of 2, '(props: Settings | Readonly): Slider', gave the following error. Type 'MutableRefObject<Slider | undefined>' is not assignable to type 'LegacyRef | undefined'. Type 'MutableRefObject<Slider | undefined>' is not assignable to type 'RefObject'. Types of property 'current' are incompatible. Type 'Slider | undefined' is not assignable to type 'Slider | null'. Type 'undefined' is not assignable to type 'Slider | null'. Overload 2 of 2, '(props: Settings, context: any): Slider', gave the following error. Type 'MutableRefObject<Slider | undefined>' is not assignable to type 'LegacyRef | undefined'.

编辑：

No overload matches this call. Overload 1 of 2, '(props: Settings | Readonly): Slider', gave the following error. Type '{ children: Element[]; dots: boolean; infinite: boolean; speed: number; slidesToShow: number; slidesToScroll: number; prevArrow: false | Element; nextArrow: false | Element; ref: MutableRefObject<...>; }' is not assignable to type 'Readonly'. Types of property 'nextArrow' are incompatible. Type 'false | Element' is not assignable to type 'Element | undefined'. Type 'false' is not assignable to type 'Element | undefined'. Overload 2 of 2, '(props: Settings, context: any): Slider', gave the following error. Type '{ children: Element[]; dots: boolean; infinite: boolean; speed: number; slidesToShow: number; slidesToScroll: number; prevArrow: false | Element; nextArrow: false | Element; ref: MutableRefObject<...>; }' is not assignable to type 'Readonly'. Types of property 'nextArrow' are incompatible. Type 'false | Element' is not assignable to type 'Element | undefined'.

Answer 1

看到这部分错误：

Type 'Slider | undefined' is not assignable to type 'Slider | null'. Type 'undefined' is not assignable to type 'Slider | null'.

如果未传递默认值，

useRef 会将 undefined 添加到类型。您可能想像这样传递 null：

// bad:
const sliderRef = useRef<Slider>() // type: Slider | undefined
// good
const sliderRef = useRef<Slider | null>(null) // type: Slider | null

关于您的第二个错误，请看一下最后一部分，尝试推断发生了什么：

Types of property 'nextArrow' are incompatible. Type 'false | Element' is not assignable to type 'Element | undefined'.

似乎 nextArrow 接受 Element 或 undefined。目前你传递的箭头是这样的：

prevArrow: (isLargeScreen && <PrevArrow />),
nextArrow: (isLargeScreen && <NextArrow />)

请注意，如果 isLargeScreen 是 false，它将 return false 而不是 undefined，这不是 [=] 的有效类型24=]道具。将其更新为如下内容：

prevArrow: (isLargeScreen ? <PrevArrow /> : undefined),
nextArrow: (isLargeScreen ? <NextArrow /> : undefined)

useRef 抛出不可分配给类型 LegacyRef<Slider> |不明确的

useRef throws not assignable to type LegacyRef<Slider> | undefined

typescript

reactjs

react-slick

use-ref