updated 状态包含 true 或 false，具体取决于自首次打开页面以来是否部署了新版本的应用。为了使其工作，你的 svelte.config.js 必须指定 kit.version.pollInterval。

¥The updated state contains true or false depending on whether a new version of the app has been deployed since the page was first opened. For this to work, your svelte.config.js must specify kit.version.pollInterval.

<script>
	import { page, navigating, updated } from '$app/state';
</script>

<script lang="ts">
	import { page, navigating, updated } from '$app/state';
</script>

版本更改仅发生在生产中，而不是在开发期间。因此，本教程中的 updated.current 将始终为 false。

¥Version changes only happen in production, not during development. For that reason, updated.current will always be false in this tutorial.

你可以通过调用 updated.check() 手动检查新版本，而不管 pollInterval 如何。

¥You can manually check for new versions, regardless of pollInterval, by calling updated.check().

{#if updated.current}
	<div class="toast">
		<p>
			A new version of the app is available

			<button onclick={() => location.reload()}>
				reload the page
			</button>
		</p>
	</div>
{/if}

在 SvelteKit 2.12 之前，你必须为此使用 $app/stores，它为 $updated 存储提供相同的信息。如果你目前正在使用 $app/stores，我们建议你迁移到 $app/state（需要 Svelte 5）。

¥[!NOTE] Prior to SvelteKit 2.12, you had to use $app/stores for this, which provides an $updated store with the same information. If you’re currently using $app/stores, we advise you to migrate towards $app/state (requires Svelte 5).