Svelte 过渡事件
了解过渡的开始和结束可能会很有用。Svelte调度监听事件，像监听其他任何DOM事件一样：<p
transition:fly="{{ y: 200, duration: 2000 }}"
on:introstart="{() => status = 'intro started'}"
on:outrostart="{() => status = 'outro started'}"
on:introend="{() => status = 'intro ended'}"
on:outroend="{() => status = 'outro ended'}"
>
Flies in and out
</p>示例代码App.svelte<script>
import { fly } from 'svelte/transition';
let visible = true;let status = 'waiting...';
</script>
<p>status: {status}</p>
<label>
<input type="checkbox" bind:checked={visible}>
visible
</label>
{#if visible}
<p
transition:fly="{{ y: 200, duration: 2000 }}"
on:introstart="{() => status = 'intro started'}"
on:outrostart="{() => status = 'outro started'}"
on:introend="{() => status = 'intro ended'}"
on:outroend="{() => status = 'outro ended'}"
>
Flies in and out
</p>
{/if}