HorizontalPager

一个用于可滑动页面的 Jetpack Compose HorizontalPager 组件。

Android

Included in Expo Go

GitHub

npm

更新日志

Recommended version:

~57.0.0

Expo UI HorizontalPager 与 Jetpack Compose 的 HorizontalPager 匹配——这是一个水平滚动的分页器，会吸附到各个单独页面。

HorizontalPager 不会强制设定自身的高度——请使用 height 修饰符为其指定高度，或将其放置在具有有限高度的父容器中。

安装

Terminal

- npx expo install @expo/ui

If you are installing this in an existing React Native app, make sure to install expo in your project.

用法

非受控

分页器原生管理其滚动位置。使用 initialPage 选择起始页，并通过 onCurrentPageChange 监听变化（在滑动过程中、snap 目标切换时触发），或通过 onSettledPageChange 监听变化（仅在滑动结束并稳定后触发）。

UncontrolledPagerExample.tsx

import { Box, Column, Host, HorizontalPager, Text } from '@expo/ui/jetpack-compose';
import { background, fillMaxSize, fillMaxWidth, height } from '@expo/ui/jetpack-compose/modifiers';
import { useState } from 'react';

export default function UncontrolledPagerExample() {
  const [currentPage, setCurrentPage] = useState(1);
  const [settledPage, setSettledPage] = useState(1);

  return (
    <Host matchContents={{ vertical: true }} style={{ width: '100%' }}>
      <Column verticalArrangement={{ spacedBy: 12 }} modifiers={[fillMaxWidth()]}>
        <Text style={{ typography: 'titleLarge' }}>
          currentPage: {currentPage} · settledPage: {settledPage}
        </Text>
        <HorizontalPager
          initialPage={1}
          onCurrentPageChange={setCurrentPage}
          onSettledPageChange={setSettledPage}
          modifiers={[fillMaxWidth(), height(240)]}>
          <Page label="第 1 页" color="#6200EE" />
          <Page label="第 2 页" color="#03DAC5" />
          <Page label="第 3 页" color="#FF5722" />
        </HorizontalPager>
      </Column>
    </Host>
  );
}

function Page({ label, color }: { label: string; color: string }) {
  return (
    <Box modifiers={[fillMaxSize(), background(color)]} contentAlignment="center">
      <Text color="#FFFFFF" style={{ typography: 'headlineLarge' }}>
        {label}
      </Text>
    </Box>
  );
}

程序化导航

附加一个 ref，然后在其上调用 animateScrollToPage 或 scrollToPage。这两个方法分别对应 Compose 的 PagerState.animateScrollToPage 和 PagerState.scrollToPage。

ProgrammaticPagerExample.tsx

import {
  Box,
  Button,
  Column,
  Host,
  HorizontalPager,
  type HorizontalPagerHandle,
  Row,
  Text,
} from '@expo/ui/jetpack-compose';
import { background, fillMaxSize, fillMaxWidth, height } from '@expo/ui/jetpack-compose/modifiers';
import { useRef, useState } from 'react';

const PAGE_COUNT = 5;

export default function ProgrammaticPagerExample() {
  const pagerRef = useRef<HorizontalPagerHandle>(null);
  const [page, setPage] = useState(0);

  return (
    <Host matchContents={{ vertical: true }} style={{ width: '100%' }}>
      <Column verticalArrangement={{ spacedBy: 12 }} modifiers={[fillMaxWidth()]}>
        <Text style={{ typography: 'titleLarge' }}>
          第 {page + 1} 页 / {PAGE_COUNT}
        </Text>
        <HorizontalPager
          ref={pagerRef}
          onSettledPageChange={setPage}
          modifiers={[fillMaxWidth(), height(200)]}>
          {Array.from({ length: PAGE_COUNT }).map((_, i) => (
            <Page key={i} label={`第 ${i + 1} 页`} color={COLORS[i]} />
          ))}
        </HorizontalPager>
        <Row horizontalArrangement={{ spacedBy: 8 }}>
          <Button onClick={() => pagerRef.current?.animateScrollToPage(Math.max(0, page - 1))}>
            <Text>上一页</Text>
          </Button>
          <Button
            onClick={() =>
              pagerRef.current?.animateScrollToPage(Math.min(PAGE_COUNT - 1, page + 1))
            }>
            <Text>下一页</Text>
          </Button>
          <Button onClick={() => pagerRef.current?.scrollToPage(0)}>
            <Text>跳转到第一页</Text>
          </Button>
        </Row>
      </Column>
    </Host>
  );
}

const COLORS = ['#6200EE', '#03DAC5', '#FF5722', '#4CAF50', '#2196F3'];

function Page({ label, color }: { label: string; color: string }) {
  return (
    <Box modifiers={[fillMaxSize(), background(color)]} contentAlignment="center">
      <Text color="#FFFFFF" style={{ typography: 'headlineLarge' }}>
        {label}
      </Text>
    </Box>
  );
}

页面间距和内容内边距

使用 pageSpacing 在页面之间添加间隙（在滑动时可见），并使用 contentPadding 为分页器添加内边距，使相邻页面在静止时露出一部分。

PagerLayoutExample.tsx

import { Box, Host, HorizontalPager, Text } from '@expo/ui/jetpack-compose';
import { background, fillMaxSize, fillMaxWidth, height } from '@expo/ui/jetpack-compose/modifiers';

export default function PagerLayoutExample() {
  return (
    <Host matchContents={{ vertical: true }} style={{ width: '100%' }}>
      <HorizontalPager
        pageSpacing={12}
        contentPadding={{ start: 32, end: 32 }}
        modifiers={[fillMaxWidth(), height(180)]}>
        <Page label="第 1 页" color="#6200EE" />
        <Page label="第 2 页" color="#03DAC5" />
        <Page label="第 3 页" color="#FF5722" />
      </HorizontalPager>
    </Host>
  );
}

function Page({ label, color }: { label: string; color: string }) {
  return (
    <Box modifiers={[fillMaxSize(), background(color)]} contentAlignment="center">
      <Text color="#FFFFFF" style={{ typography: 'headlineLarge' }}>
        {label}
      </Text>
    </Box>
  );
}

API

import { HorizontalPager } from '@expo/ui/jetpack-compose';

Component

`HorizontalPager`

Android

Type: React.Element<HorizontalPagerProps>

A horizontally scrolling pager that snaps to individual pages, matching Compose's HorizontalPager.

HorizontalPagerProps

`beyondViewportPageCount`

Android

Optional • Type: number • Default: 0

Number of pages to compose and keep beyond the visible viewport.

`children`

Android

Type: ReactNode

Children to render as pages.

`contentPadding`

Android

Optional • Literal type: union • Default: 0

Padding for pager content (dp or per-side object).

Acceptable values are: number | PaddingValuesRecord

`initialPage`

Android

Optional • Type: number • Default: 0

Page to mount on. Mirrors rememberPagerState(initialPage = …). Subsequent changes have no effect — use the ref methods to navigate after mount.

`modifiers`

Android

Optional • Type: ModifierConfig[]

Modifiers for the component.

`onCurrentPageChange`

Android

Optional • Type: (page: number) => void

Fires when Compose's PagerState.currentPage changes — i.e. when the page closest to the snap position flips, including mid-swipe as the user crosses between pages.

`onDragInteraction`

Android

Optional • Type: (kind: HorizontalPagerDragInteraction) => void

Fires for each drag interaction emitted by PagerState.interactionSource. Combine with onScrollInProgressChange to distinguish user dragging from fling/snap-settling.

`onPageScroll`

Android

Optional • Type: (currentPage: number, currentPageOffsetFraction: number) => void

Fires continuously while a swipe is in progress. Mirrors Compose's PagerState.currentPage and currentPageOffsetFraction — the latter is the signed fractional offset from currentPage, in the [-0.5, 0.5] range.

If the callback is marked with the 'worklet' directive, it runs synchronously on the UI thread; otherwise it is delivered asynchronously as a regular JS event.

`onScrollInProgressChange`

Android

Optional • Type: (isScrollInProgress: boolean) => void

Fires when Compose's PagerState.isScrollInProgress toggles — true while the pager is being dragged or animating to a snap target, false once it has settled.

`onSettledPageChange`

Android

Optional • Type: (page: number) => void

Fires when Compose's PagerState.settledPage changes — i.e. after a swipe or programmatic scroll has fully settled.

`pageSpacing`

Android

Optional • Type: number • Default: 0

Spacing between pages in dp.

`ref`

Android

Optional • Type: Ref<HorizontalPagerHandle>

Imperative handle for programmatic navigation. Mirrors the methods on Compose's PagerState.

`reverseLayout`

Android

Optional • Type: boolean • Default: false

Whether to reverse the layout direction.

`userScrollEnabled`

Android

Optional • Type: boolean • Default: true

Whether the user can scroll the pager by swiping.

Types

`HorizontalPagerDragInteraction`

Android

Literal type: string

Kind of drag interaction reported by onDragInteraction. Mirrors Compose's DragInteraction.Start / DragInteraction.Stop / DragInteraction.Cancel.

Acceptable values are: 'start' | 'stop' | 'cancel'

`HorizontalPagerHandle`

Android

Property	Type	Description
animateScrollToPage	`(page: number) => Promise<void>`	Mirrors Compose's `PagerState.animateScrollToPage`. Resolves when the animation completes.
scrollToPage	`(page: number) => Promise<void>`	Mirrors Compose's `PagerState.scrollToPage`. Jumps without animation.

`PaddingValuesRecord`

Android

Per-side padding values in dp for the content.

Property	Type	Description
bottom(optional)	`number`	-
end(optional)	`number`	-
start(optional)	`number`	-
top(optional)	`number`	-