如何传递嵌套在另一个组件中的组件的当前索引？

Question

我有一个英雄组件，里面有一个背景图像和一个轮播。我想在轮播中滑动上一张和下一张时更改背景图像，具体取决于轮播中当前显示的内容。 CarouselPrev 和 CarouselNext 是从 carousel 组件导出的。它们在那里应用了 onClick 函数，因此我无法将 onClick 函数应用于我的英雄组件中的这些组件，否则它们将相互覆盖。

轮播：

import * as React from "react";
import useEmblaCarousel, {
  type UseEmblaCarouselType,
} from "embla-carousel-react";
import { ArrowLeft, ArrowRight } from "lucide-react";

import { cn } from "@/lib/utils";
import { Button } from "@/Components/ui/Button";

type CarouselApi = UseEmblaCarouselType[1];
type UseCarouselParameters = Parameters<typeof useEmblaCarousel>;
type CarouselOptions = UseCarouselParameters[0];
type CarouselPlugin = UseCarouselParameters[1];

type CarouselProps = {
  opts?: CarouselOptions;
  plugins?: CarouselPlugin;
  orientation?: "horizontal" | "vertical";
  setApi?: (api: CarouselApi) => void;
  currentIndex: number;
};

type CarouselContextProps = {
  carouselRef: ReturnType<typeof useEmblaCarousel>[0];
  api: ReturnType<typeof useEmblaCarousel>[1];
  scrollPrev: () => void;
  scrollNext: () => void;
  canScrollPrev: boolean;
  canScrollNext: boolean;
  currentIndex: number;
} & CarouselProps;

const CarouselContext = React.createContext<CarouselContextProps | null>(null);

function useCarousel() {
  const context = React.useContext(CarouselContext);

  if (!context) {
    throw new Error("useCarousel must be used within a <Carousel />");
  }

  return context;
}

const Carousel = React.forwardRef<
  HTMLDivElement,
  React.HTMLAttributes<HTMLDivElement> & CarouselProps
>(
  (
    {
      orientation = "horizontal",
      opts,
      setApi,
      plugins,
      className,
      children,
      ...props
    },
    ref
  ) => {
    const [carouselRef, api] = useEmblaCarousel(
      {
        ...opts,
        axis: orientation === "horizontal" ? "x" : "y",
      },
      plugins
    );
    const [canScrollPrev, setCanScrollPrev] = React.useState(false);
    const [canScrollNext, setCanScrollNext] = React.useState(false);
    const [currentIndex, setCurrentIndex] = React.useState(0);

    const onSelect = React.useCallback((api: CarouselApi) => {
      if (!api) {
        return;
      }

      setCanScrollPrev(api.canScrollPrev());
      setCanScrollNext(api.canScrollNext());
      setCurrentIndex(api.selectedScrollSnap());
    }, []);

    const scrollPrev = React.useCallback(() => {
      api?.scrollPrev();
    }, [api]);

    const scrollNext = React.useCallback(() => {
      api?.scrollNext();
    }, [api]);

    const handleKeyDown = React.useCallback(
      (event: React.KeyboardEvent<HTMLDivElement>) => {
        if (event.key === "ArrowLeft") {
          event.preventDefault();
          scrollPrev();
        } else if (event.key === "ArrowRight") {
          event.preventDefault();
          scrollNext();
        }
      },
      [scrollPrev, scrollNext]
    );

    React.useEffect(() => {
      if (!api || !setApi) {
        return;
      }

      setApi(api);
    }, [api, setApi]);

    React.useEffect(() => {
      if (!api) {
        return;
      }

      onSelect(api);
      api.on("reInit", onSelect);
      api.on("select", onSelect);

      return () => {
        api?.off("select", onSelect);
      };
    }, [api, onSelect]);

    return (
      <CarouselContext.Provider
        value={{
          carouselRef,
          api: api,
          opts,
          orientation:
            orientation || (opts?.axis === "y" ? "vertical" : "horizontal"),
          scrollPrev,
          scrollNext,
          canScrollPrev,
          canScrollNext,
          currentIndex
        }}
      >
        <div
          ref={ref}
          onKeyDownCapture={handleKeyDown}
          className={cn("relative", className)}
          role="region"
          aria-roledescription="carousel"
          {...props}
        >
          {children}
        </div>
      </CarouselContext.Provider>
    );
  }
);
Carousel.displayName = "Carousel";

const CarouselContent = React.forwardRef<
  HTMLDivElement,
  React.HTMLAttributes<HTMLDivElement>
>(({ className, ...props }, ref) => {
  const { carouselRef, orientation } = useCarousel();

  return (
    <div ref={carouselRef} className="overflow-hidden w-1/2 -ml-36">
      <div
        ref={ref}
        className={cn(
          "flex flex-row-reverse",
          orientation === "horizontal" ? "-ml-4" : "-mt-4 flex-col",
          className
        )}
        {...props}
      />
    </div>
  );
});
CarouselContent.displayName = "CarouselContent";

const CarouselItem = React.forwardRef<
  HTMLDivElement,
  React.HTMLAttributes<HTMLDivElement>
>(({ className, ...props }, ref) => {
  const { orientation } = useCarousel();

  return (
    <div
      ref={ref}
      role="group"
      aria-roledescription="slide"
      className={cn(
        "min-w-0 shrink-0 grow-0 basis-full",
        orientation === "horizontal" ? "pl-8" : "pt-4",
        className
      )}
      {...props}
    />
  );
});
CarouselItem.displayName = "CarouselItem";

const CarouselPrevious = React.forwardRef<
  HTMLButtonElement,
  React.ComponentProps<typeof Button>
>(({ className, variant = "outline", size = "icon", ...props }, ref) => {
  const { orientation, scrollPrev, canScrollPrev } = useCarousel();

  return (
    <Button
      ref={ref}
      variant={variant}
      size={size}
      className={cn(
        "absolute h-8 w-8 rounded-full",
        orientation === "horizontal"
          ? "bottom-1/4 right-12"
          : "-top-12 left-1/2 -translate-x-1/2 rotate-90",
        className
      )}
      disabled={!canScrollPrev}
      onClick={scrollPrev}
      {...props}
    >
      <ArrowLeft className="h-4 w-4" />
      <span className="sr-only">Previous slide</span>
    </Button>
  );
});
CarouselPrevious.displayName = "CarouselPrevious";

const CarouselNext = React.forwardRef<
  HTMLButtonElement,
  React.ComponentProps<typeof Button>
>(({ className, variant = "outline", size = "icon", ...props }, ref) => {
  const { orientation, scrollNext, canScrollNext } = useCarousel();

  return (
    <Button
      ref={ref}
      variant={variant}
      size={size}
      className={cn(
        "absolute h-8 w-8 rounded-full",
        orientation === "horizontal"
          ? "bottom-1/4 right-0"
          : "-bottom-12 left-1/2 -translate-x-1/2 rotate-90",
        className
      )}
      disabled={!canScrollNext}
      onClick={scrollNext}
      {...props}
    >
      <ArrowRight className="h-4 w-4" />
      <span className="sr-only">Next slide</span>
    </Button>
  );
});
CarouselNext.displayName = "CarouselNext";

export {
  type CarouselApi,
  Carousel,
  CarouselContent,
  CarouselItem,
  CarouselPrevious,
  CarouselNext,
};

英雄：

import { getTop10 } from "@/lib/utils";
import {
  Carousel,
  CarouselContent,
  CarouselItem,
  CarouselNext,
  CarouselPrevious,
} from "@/Components/ui/carousel";
import React, { useState, useEffect } from 'react';
import { Card, CardContent } from "@/Components/ui/card";

const Hero = () => {
  const [top10, setTop10] = useState<any[]>([]);

  useEffect(() => {
    const fetchTop10 = async () => {
      try {
        const movies = await getTop10();

        if(Array.isArray(movies?.results)){
          setTop10(movies.results.slice(0, 10));
        } else {
          console.error('Data is not an array:', movies);
        }
      }
      catch(error) {
        console.error('Error fetching top10:', error);
      }
    };
    fetchTop10();

  }, []);

  
  const [currentMovieIndex, setCurrentMovieIndex] = useState(0);

  function handlePreviousClick() {
    setCurrentMovieIndex((prevIndex) => (prevIndex === 0 ? top10.length-1 : prevIndex - 1));
  }
  
  function handleNextClick() {
    setCurrentMovieIndex((prevIndex) => (prevIndex === top10.length-1 ? 0 : prevIndex + 1));
  }

  return (
    <div
      style={{ backgroundImage: `url(https://image.tmdb.org/t/p/original/${top10[currentMovieIndex]?.backdrop_path})`, backgroundPosition: "center" }}
      className="w-full h-[1000px] bg-cover bg-center"
    > 
      <div className="container mx-auto pt-60 text-6xl text-white font-bold flex flex-col gap-6">
        <h1>{top10[currentMovieIndex]?.original_title}</h1>
        <div className="flex flex-row gap-4 items-center">
          <span className="px-4 py-1 bg-amber-700 text-black text-xl rounded h-fit">
            IMDB
          </span>
          <span className="text-3xl font-medium">{top10[currentMovieIndex]?.vote_average} / 10</span>
        </div>
        <Carousel
          opts={{
            align: "end",
            direction: "rtl",
            loop: true,
            duration: 40,
          }}
          className="w-full mt-20"
          currentIndex={0}
        >
          <CarouselContent>
            {top10.map((movie: any, index: number) => (
              <CarouselItem key={index} className="basis-1/3">
                <div className="p-1">
                  <Card style={{ backgroundImage: `url(https://image.tmdb.org/t/p/original/${movie?.poster_path})`, backgroundPosition: "center" }} className="bg-cover bg-center w-full">
                    <CardContent />
                  </Card>
                </div>
              </CarouselItem>
            ))}
          </CarouselContent>
          <CarouselPrevious />
          <CarouselNext />
        </Carousel>
      </div>
    </div>
  );
}

export default Hero;

Embla Docs 有一个名为

selectedScrollSnap

的方法，可以跟踪索引，但我不知道如何使用它并将值传递到我的轮播。然后我不确定这是否是尝试实现我正在寻找的功能的正确方法。

Answer 1

不确定我写这篇文章时在做什么。我只是将 Hero 组件内的 CarouselNext 和 CarouselPrevious 组件包装在一个 div 中，并将 onClick 放在这些 div 上。然后摆脱了我在 Carousel 组件中使用 ScrollSnap 所做的所有奇怪的事情。

<div onClick={handlePreviousClick}>
  <CarouselPrevious />
</div>
<div onClick={handleNextClick}>
  <CarouselNext />
</div>