This is documentation for the next SDK version. For up-to-date documentation, see the latest version (SDK 57).

NavigationBar

一个适用于 Material 3 底部导航的 Jetpack Compose NavigationBar 组件。

Android

Included in Expo Go

GitHub

npm

更新日志

Expo UI NavigationBar 与官方 Jetpack Compose NavigationBar API 匹配。它显示一排目的地，用于在应用顶级部分之间切换。

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

基础导航栏

在 React state 中管理选中的项，并将 selected 传递给每个 NavigationBarItem。

BasicNavigationBar.tsx

import { useState } from 'react';
import { Host, Icon, NavigationBar, NavigationBarItem, Text } from '@expo/ui/jetpack-compose';

const HOME_ICON = require('./assets/home.xml');
const SEARCH_ICON = require('./assets/search.xml');
const SETTINGS_ICON = require('./assets/settings.xml');

export default function BasicNavigationBar() {
  const [selectedTab, setSelectedTab] = useState('home');

  return (
    <Host matchContents>
      <NavigationBar>
        <NavigationBarItem selected={selectedTab === 'home'} onClick={() => setSelectedTab('home')}>
          <NavigationBarItem.Icon>
            <Icon source={HOME_ICON} />
          </NavigationBarItem.Icon>
          <NavigationBarItem.Label>
            <Text>首页</Text>
          </NavigationBarItem.Label>
        </NavigationBarItem>

        <NavigationBarItem
          selected={selectedTab === 'search'}
          onClick={() => setSelectedTab('search')}>
          <NavigationBarItem.Icon>
            <Icon source={SEARCH_ICON} />
          </NavigationBarItem.Icon>
          <NavigationBarItem.Label>
            <Text>搜索</Text>
          </NavigationBarItem.Label>
        </NavigationBarItem>

        <NavigationBarItem
          selected={selectedTab === 'settings'}
          onClick={() => setSelectedTab('settings')}>
          <NavigationBarItem.Icon>
            <Icon source={SETTINGS_ICON} />
          </NavigationBarItem.Icon>
          <NavigationBarItem.Label>
            <Text>设置</Text>
          </NavigationBarItem.Label>
        </NavigationBarItem>
      </NavigationBar>
    </Host>
  );
}

API

import { NavigationBar, NavigationBarItem } from '@expo/ui/jetpack-compose';

Components

`NavigationBar`

Android

Type: React.Element<NavigationBarProps>

A Material Design 3 navigation bar.

NavigationBarProps

`children`

Android

Optional • Type: ReactNode

Navigation bar items.

`containerColor`

Android

Optional • Type: ColorValue • Default: NavigationBarDefaults.containerColor

Background color of the navigation bar.

`contentColor`

Android

Optional • Type: ColorValue • Default: contentColorFor(containerColor)

Preferred content color inside the navigation bar.

`modifiers`

Android

Optional • Type: ModifierConfig[]

Modifiers for the component.

`tonalElevation`

Android

Optional • Type: number • Default: NavigationBarDefaults.Elevation

Tonal elevation in dp.

`NavigationBarItem`

Android

Type: React.Element<NavigationBarItemProps>

A Material Design 3 navigation bar item. Must be used inside NavigationBar.

NavigationBarItemProps

`alwaysShowLabel`

Android

Optional • Type: boolean • Default: true

Whether to always show the label.

`children`

Android

Optional • Type: ReactNode

Children containing Icon, SelectedIcon, and Label slots.

`colors`

Android

Optional • Type: NavigationBarItemColors

Colors for the item in different states.

`enabled`

Android

Optional • Type: boolean • Default: true

Whether the item is enabled.

`modifiers`

Android

Optional • Type: ModifierConfig[]

Modifiers for the component.

`onClick`

Android

Optional • Type: () => void

Callback that is called when the item is clicked.

`selected`

Android

Type: boolean

Whether this item is currently selected.

Types

`NavigationBarItemColors`

Android

Colors for navigation bar items in different states.

Property	Type	Description
disabledIconColor(optional)	`ColorValue`	-
disabledTextColor(optional)	`ColorValue`	-
selectedIconColor(optional)	`ColorValue`	-
selectedIndicatorColor(optional)	`ColorValue`	-
selectedTextColor(optional)	`ColorValue`	-
unselectedIconColor(optional)	`ColorValue`	-
unselectedTextColor(optional)	`ColorValue`	-

Components

`NavigationBar`

Android

Type: React.Element<NavigationBarProps>

A Material Design 3 navigation bar.

NavigationBarProps

`children`

Android

Optional • Type: ReactNode

Navigation bar items.

`containerColor`

Android

Optional • Type: ColorValue • Default: NavigationBarDefaults.containerColor

Background color of the navigation bar.

`contentColor`

Android

Optional • Type: ColorValue • Default: contentColorFor(containerColor)

Preferred content color inside the navigation bar.

`modifiers`

Android

Optional • Type: ModifierConfig[]

Modifiers for the component.

`tonalElevation`

Android

Optional • Type: number • Default: NavigationBarDefaults.Elevation

Tonal elevation in dp.

`NavigationBarItem`

Android

Type: React.Element<NavigationBarItemProps>

A Material Design 3 navigation bar item. Must be used inside NavigationBar.

NavigationBarItemProps

`alwaysShowLabel`

Android

Optional • Type: boolean • Default: true

Whether to always show the label.

`children`

Android

Optional • Type: ReactNode

Children containing Icon, SelectedIcon, and Label slots.

`colors`

Android

Optional • Type: NavigationBarItemColors

Colors for the item in different states.

`enabled`

Android

Optional • Type: boolean • Default: true

Whether the item is enabled.

`modifiers`

Android

Optional • Type: ModifierConfig[]

Modifiers for the component.

`onClick`

Android

Optional • Type: () => void

Callback that is called when the item is clicked.

`selected`

Android

Type: boolean

Whether this item is currently selected.

Types

`NavigationBarItemColors`

Android

Colors for navigation bar items in different states.

Property	Type	Description
disabledIconColor(optional)	`ColorValue`	-
disabledTextColor(optional)	`ColorValue`	-
selectedIconColor(optional)	`ColorValue`	-
selectedIndicatorColor(optional)	`ColorValue`	-
selectedTextColor(optional)	`ColorValue`	-
unselectedIconColor(optional)	`ColorValue`	-
unselectedTextColor(optional)	`ColorValue`	-