主题
useElementVisibility
跟踪视口中元素的可见性。
¥Tracks the visibility of an element within the viewport.
示例
用法
¥Usage
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
如果你希望在元素完全可见之前尽早触发回调，则可以使用 rootMargin 选项（参见 MDN IntersectionObserver/rootMargin）。
¥If you wish to trigger your callback sooner before the element is fully visible, you can use the rootMargin option (See MDN IntersectionObserver/rootMargin).
ts
const targetIsVisible = useElementVisibility(target, {
rootMargin: '0px 0px 100px 0px',
})组件用法
¥Component Usage
vue
<template>
<UseElementVisibility v-slot="{ isVisible }">
Is Visible: {{ isVisible }}
</UseElementVisibility>
</template>指令用法
¥Directive Usage
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-visibility="onElementVisibility">
{{ isVisible ? 'inside' : 'outside' }}
</div>
<!-- with options -->
<div ref="target">
<div v-element-visibility="[onElementVisibility, { scrollTarget: target }]">
{{ isVisible ? 'inside' : 'outside' }}
</div>
</div>
</template>类型声明
typescript
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
}
/**
* Tracks the visibility of an element within the viewport.
*
* @see https://vueuse.org/useElementVisibility
*/
export declare function useElementVisibility(
element: MaybeComputedElementRef,
options?: UseElementVisibilityOptions,
): ShallowRef<boolean, boolean>