useIntersectionObserver

类别

Elements

导出体积

646 B

上次更改

last week

检测目标元素可见性的变化。

示例

源码 playground (beta)

启用

RootMargin: 0px 0px 0px 0px

向下滚动我！

Hello world!

元素外部视口

使用方法

vue

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

const target
 = useTemplateRef
('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>

指令使用

vue

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

const root
 = useTemplateRef
('root')

const isVisible
 = shallowRef
(false)

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

<template>
  <div
>
    <p
>
      向下滚动！
    </p
>
    <div
 v-intersection-observ
er="onIntersectionObserver
">
      <p
>Hello world!</p
>
    </div
>
  </div
>

  <!-- 使用选项 -->
  <div
 ref
="root
">
    <p
>
      向下滚动！
    </p
>
    <div
 v-intersection-observ
er="[
onIntersectionObserver
, { 
root
 }]
">
      <p
>Hello world!</p
>
    </div
>
  </div
>
</template>

IntersectionObserver MDN 文档

类型声明

export interface UseIntersectionObserverOptions extends ConfigurableWindow {
  /**
   * 在创建时立即启动 IntersectionObserver
   *
   * @default true
   */
  immediate
?: boolean
  /**
   * 用作边界框的元素或文档，用于测试相交时使用的边界框。
   */
  root
?: MaybeComputedElementRef
 | Document
  /**
   * 一个字符串，指定计算相交时要添加到根边界框的偏移量集。
   */
  rootMargin
?: MaybeRefOrGetter
<string>
  /**
   * 单个数字或介于 0.0 和 1 之间的数字数组。
   * @default 0
   */
  threshold
?: number | number[]
}
export interface UseIntersectionObserverReturn extends Supportable, Pausable {
  stop
: () => void
}
/**
 * Detects changes to a target element's visibility.
 *
 * @see https://vueuse.org/useIntersectionObserver
 * @param target
 * @param callback
 * @param options
 */
export declare function useIntersectionObserver
(
  target
:
    | MaybeComputedElementRef

    | MaybeRefOrGetter
<MaybeElement
[]>
    | MaybeComputedElementRef
[],
  callback
: IntersectionObserverCallback,
  options
?: UseIntersectionObserverOptions,
): UseIntersectionObserverReturn