useIntersectionObserver

类别

元素

导出大小

642 B

最后更改

5 天前

检测目标元素的可见性。

演示

源代码

启用

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元素在视口外

用法

vue

<script setup lang="ts">
import { useIntersectionObserver } from '@vueuse/core'
import { shallowRef, useTemplateRef } from 'vue'

const target = useTemplateRef<HTMLDivElement>('target')
const targetIsVisible = shallowRef(false)

const { stop } = useIntersectionObserver(
  target,
  ([entry], observerElement) => {
    targetIsVisible.value = entry?.isIntersecting || false
  },
)
</script>

<template>
  <div ref="target">
    <h1>Hello world</h1>
  </div>
</template>

指令用法

此函数还通过 @vueuse/components 包提供了一个指令版本。了解更多关于用法的信息。

vue

<script setup lang="ts">
import { vIntersectionObserver } from '@vueuse/components'
import { shallowRef, useTemplateRef } from 'vue'

const root = useTemplateRef<HTMLDivElement>('root')

const isVisible = shallowRef(false)

function onIntersectionObserver([entry]: IntersectionObserverEntry[]) {
  isVisible.value = entry?.isIntersecting || false
}
</script>

<template>
  <div>
    <p>
      Scroll me down!
    </p>
    <div v-intersection-observer="onIntersectionObserver">
      <p>Hello world!</p>
    </div>
  </div>

  <!-- with options -->
  <div ref="root">
    <p>
      Scroll me down!
    </p>
    <div v-intersection-observer="[onIntersectionObserver, { root }]">
      <p>Hello world!</p>
    </div>
  </div>
</template>

IntersectionObserver MDN

类型声明

显示类型声明

typescript

export interface UseIntersectionObserverOptions extends ConfigurableWindow {
  /**
   * Start the IntersectionObserver immediately on creation
   *
   * @default true
   */
  immediate?: boolean
  /**
   * The Element or Document whose bounds are used as the bounding box when testing for intersection.
   */
  root?: MaybeComputedElementRef | Document
  /**
   * A string which specifies a set of offsets to add to the root's bounding_box when calculating intersections.
   */
  rootMargin?: string
  /**
   * Either a single number or an array of numbers between 0.0 and 1.
   * @default 0
   */
  threshold?: number | number[]
}
export interface UseIntersectionObserverReturn extends Pausable {
  isSupported: ComputedRef<boolean>
  stop: () => void
}
/**
 * Detects that a target element's visibility.
 *
 * @see https://vueuse.org.cn/useIntersectionObserver
 * @param target
 * @param callback
 * @param options
 */
export declare function useIntersectionObserver(
  target:
    | MaybeComputedElementRef
    | MaybeRefOrGetter<MaybeElement[]>
    | MaybeComputedElementRef[],
  callback: IntersectionObserverCallback,
  options?: UseIntersectionObserverOptions,
): UseIntersectionObserverReturn