useElementVisibility

类别

Elements

导出体积

793 B

上次更改

last week

跟踪元素在视口内的可见性。

示例

源码 playground (beta)

右下角的信息

目标元素（向下滚动）

元素外部视口

用法

vue

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

const target
 = useTemplateRef
<HTMLDivElement>('target')
const targetIsVisible
 = useElementVisibility
(target
)
</script>

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

rootMargin

如果你想在元素完全可见之前更早地触发回调，可以使用 rootMargin 选项（参见 MDN IntersectionObserver/rootMargin）。

const targetIsVisible
 = useElementVisibility
(target, {
  rootMargin
: '0px 0px 100px 0px',
})

threshold

如果您想控制更新值所需的可见性百分比，可以使用 threshold 选项（请参见 MDN IntersectionObserver/threshold）。

const targetIsVisible
 = useElementVisibility(target, {
  threshold
: 1.0, // 100% visible
})

组件用法

vue

<template>
  <UseElementVisibility v-slot="{ isVisible
 }">
    是否可见：{{ isVisible
 }}
  </UseElementVisibility>
</template>

指令用法

vue

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

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

function onElementVisibility
(state
) {
  isVisible
.value
 = state

}
</script>

<template>
  <div
 v-element-visibili
ty="onElementVisibility
">
    {{ isVisible
 ? '在内部' : '在外部' }}
  </div
>

  <!-- 使用选项 -->
  <div
 ref
="target
">
    <div
 v-element-visibili
ty="[
onElementVisibility
, { 
scrollTarget
: 
target
 }]
">
      {{ isVisible
 ? '在内部' : '在外部' }}
    </div
>
  </div
>
</template>

类型声明

export interface UseElementVisibilityOptions
  extends ConfigurableWindow,
    Pick
<UseIntersectionObserverOptions
, "threshold"> {
  /**
   * @see https://developer.mozilla.org/en-US/docs/Web/API/IntersectionObserver/rootMargin
   */
  rootMargin
?: MaybeRefOrGetter
<string>
  /**
   * The element that is used as the viewport for checking visibility of the target.
   */
  scrollTarget
?: MaybeRefOrGetter
<HTMLElement | undefined | null>
  /**
   * Stop tracking when element visibility changes for the first time
   *
   * @default false
   */
  once
?: boolean
}
/**
 * 跟踪元素在视口中的可见性
 *
 * @see https://vueuse.org/useElementVisibility
 */
export declare function useElementVisibility
(
  element
: MaybeComputedElementRef
,
  options
?: UseElementVisibilityOptions,
): ShallowRef
<boolean, boolean>
export type UseElementVisibilityReturn
 = ReturnType
<typeof useElementVisibility
>