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API 參考函式useSelectedLayoutSegment

useSelectedLayoutSegment

useSelectedLayoutSegment 是一個客戶端組件 Hook，可讓您讀取從中呼叫它的佈局下一層的作用中路由區段。

它適用於導航 UI，例如父佈局內部的分頁，這些分頁會根據作用中的子區段而變更樣式。

app/example-client-component.tsx
'use client'
 
import { useSelectedLayoutSegment } from 'next/navigation'
 
export default function ExampleClientComponent() {
  const segment = useSelectedLayoutSegment()
 
  return <p>Active segment: {segment}</p>
}

要知道的好資訊:

  • 由於 useSelectedLayoutSegment 是一個客戶端組件 Hook，而佈局預設為伺服器組件，因此 useSelectedLayoutSegment 通常透過匯入到佈局中的客戶端組件來呼叫。
  • useSelectedLayoutSegment 僅傳回下一層的區段。若要傳回所有作用中區段，請參閱useSelectedLayoutSegments

參數 

const segment = useSelectedLayoutSegment(parallelRoutesKey?: string)

useSelectedLayoutSegment 選擇性地接受一個parallelRoutesKey，讓您可以讀取該插槽內的作用中路由區段。

回傳值

useSelectedLayoutSegment 會傳回作用中區段的字串，如果不存在則傳回 null。

例如，假設有以下佈局和 URL，則傳回的區段將是

佈局瀏覽過的 URL傳回的區段
app/layout.js/null
app/layout.js/dashboard'dashboard'
app/dashboard/layout.js/dashboardnull
app/dashboard/layout.js/dashboard/settings'settings'
app/dashboard/layout.js/dashboard/analytics'analytics'
app/dashboard/layout.js/dashboard/analytics/monthly'analytics'

範例

您可以使用 useSelectedLayoutSegment 建立一個作用中連結組件，該組件會根據作用中區段變更樣式。例如，部落格側邊欄中的精選文章清單

app/blog/blog-nav-link.tsx
'use client'
 
import Link from 'next/link'
import { useSelectedLayoutSegment } from 'next/navigation'
 
// This *client* component will be imported into a blog layout
export default function BlogNavLink({
  slug,
  children,
}: {
  slug: string
  children: React.ReactNode
}) {
  // Navigating to `/blog/hello-world` will return 'hello-world'
  // for the selected layout segment
  const segment = useSelectedLayoutSegment()
  const isActive = slug === segment
 
  return (
    <Link
      href={`/blog/${slug}`}
      // Change style depending on whether the link is active
      style={{ fontWeight: isActive ? 'bold' : 'normal' }}
    >
      {children}
    </Link>
  )
}
app/blog/layout.tsx
// Import the Client Component into a parent Layout (Server Component)
import { BlogNavLink } from './blog-nav-link'
import getFeaturedPosts from './get-featured-posts'
 
export default async function Layout({
  children,
}: {
  children: React.ReactNode
}) {
  const featuredPosts = await getFeaturedPosts()
  return (
    <div>
      {featuredPosts.map((post) => (
        <div key={post.id}>
          <BlogNavLink slug={post.slug}>{post.title}</BlogNavLink>
        </div>
      ))}
      <div>{children}</div>
    </div>
  )
}

版本歷史

版本變更
v13.0.0useSelectedLayoutSegment 已推出。