主机

一个 SwiftUI Host 组件，可在 React Native 中启用 SwiftUI 组件。

iOS

tvOS

Included in Expo Go

GitHub

npm

更新日志

Recommended version:

~57.0.0

有关跨平台使用，请参阅通用的 Host — 它会为每个平台渲染相应的原生组件。

一个组件，允许你在 React Native 中放置其他 @expo/ui/swift-ui 组件。它的作用类似于 DOM 中的 <svg>，类似于 react-native-skia 中的 <Canvas>，其底层使用 UIHostingController 在 UIKit 中渲染 SwiftUI 视图。

由于 Host 组件是一个 React Native View，你可以向它传递 style 属性，或者传递 matchContents 属性，使 Host 组件的大小与内容大小匹配。

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

匹配内容尺寸

使用 matchContents 让 Host 自动调整自身大小以适配其 SwiftUI 内容，而不是要求显式指定尺寸。

注意： matchContents 仅适用于具有固有尺寸或显式 frame 的组件（例如 Button、Toggle、Text）。像 Slider 和线性 ProgressView 这样的可变宽度组件会扩展以填充可用空间，并且没有固有宽度，因此将 matchContents 用于它们会导致宽度接近 0。对于这些组件，要么在组件上应用 frame 修饰符以提供显式宽度，要么改为在 Host 上使用 style 进行显式尺寸设置（例如 style={{ flex: 1 }} 或 style={{ width: 300 }}）。

MatchContentsExample.tsx

import { Button, Host } from '@expo/ui/swift-ui';

export default function MatchContentsExample() {
  return (
    <Host matchContents>
      <Button
        onPress={() => {
          console.log('Pressed');
        }}>
        点击
      </Button>
    </Host>
  );
}

注意：不要在与滚动容器（ScrollView、List、Form、LazyHStack、LazyVStack）相同的轴上使用 matchContents。matchContents 会解析为 SwiftUI 的 .fixedSize，这会将滚动容器尺寸设置为其内容大小。它还会使视口之外没有任何可滚动的区域，因此滚动会悄无声息地停止工作。请将 matchContents={{ vertical: true }} 与 style={{ width: '100%' }} 一起使用（或在滚动轴上使用任何有限宽度）。

ScrollViewMatchContents.tsx

import { Host, HStack, ScrollView, Text } from '@expo/ui/swift-ui';

export default function ScrollViewMatchContents() {
  return (
    <Host matchContents={{ vertical: true }} style={{ width: '100%' }}>
      <ScrollView axes="horizontal">
        <HStack spacing={12}>
          {Array.from({ length: 20 }).map((_, i) => (
            <Text key={i}>项目 {i}</Text>
          ))}
        </HStack>
      </ScrollView>
    </Host>
  );
}

使用 style 显式设置尺寸

使用 style 为 Host 设置显式尺寸，例如通过 flex: 1 填充可用空间。

ExplicitSizingExample.tsx

import { Button, Host, VStack, Text } from '@expo/ui/swift-ui';

export default function ExplicitSizingExample() {
  return (
    <Host style={{ flex: 1 }}>
      <VStack spacing={8}>
        <Text>你好，世界！</Text>
        <Button
          onPress={() => {
            console.log('Pressed');
          }}>
          点击
        </Button>
      </VStack>
    </Host>
  );
}

忽略键盘安全区域

当 React Native 已经在处理键盘避让时（例如使用 react-native-keyboard-controller），使用 ignoreSafeArea="keyboard" 以防止 SwiftUI 宿主应用自己的键盘内边距。

IgnoreKeyboardExample.tsx

import { Host, TextField } from '@expo/ui/swift-ui';
import { KeyboardProvider, KeyboardStickyView } from 'react-native-keyboard-controller';
import { View } from 'react-native';

export default function IgnoreKeyboardExample() {
  return (
    <KeyboardProvider>
      <View style={{ flex: 1, backgroundColor: 'black' }}>
        <KeyboardStickyView
          style={{
            position: 'absolute',
            bottom: 0,
            left: 0,
            right: 0,
            padding: 16,
            backgroundColor: 'green',
          }}>
          <Host matchContents ignoreSafeArea="keyboard" style={{ backgroundColor: 'red' }}>
            <TextField placeholder="输入文本" axis="vertical" />
          </Host>
        </KeyboardStickyView>
      </View>
    </KeyboardProvider>
  );
}

忽略容器安全区域

使用 ignoreSafeArea="container" 仅移除容器安全区域（刘海、Home 指示器、状态栏和导航栏）。键盘安全区域仍然生效。

IgnoreContainerSafeAreaExample.tsx

import { Button, Host, HStack, Spacer } from '@expo/ui/swift-ui';
import { labelStyle } from '@expo/ui/swift-ui/modifiers';
import { useSafeAreaInsets } from 'react-native-safe-area-context';

export default function IgnoreContainerSafeAreaExample() {
  const insets = useSafeAreaInsets();
  return (
    <Host
      style={{ width: '100%', paddingTop: insets.top }}
      matchContents={{ vertical: true }}
      ignoreSafeArea="container">
      <HStack>
        <Button systemImage="chevron.backward" label="Back" modifiers={[labelStyle('iconOnly')]} />
        <Spacer />
        <Button
          systemImage="square.and.arrow.up"
          label="Share"
          modifiers={[labelStyle('iconOnly')]}
        />
      </HStack>
    </Host>
  );
}

忽略所有安全区域

当你希望 SwiftUI 内容延伸到状态栏和键盘后方时，使用 ignoreSafeArea="all"，这对于全屏覆盖层或背景非常有用。

IgnoreAllSafeAreasExample.tsx

import { Host, Text, VStack } from '@expo/ui/swift-ui';

export default function IgnoreAllSafeAreasExample() {
  return (
    <Host
      ignoreSafeArea="all"
      style={{ position: 'absolute', top: 0, left: 0, right: 0, bottom: 0 }}>
      <VStack>
        <Text>此内容会延伸到状态栏和底部 Home 指示器后方。</Text>
      </VStack>
    </Host>
  );
}

API

import { Host } from '@expo/ui/swift-ui';

Component

`Host`

iOS

tvOS

Type: React.Element<HostProps>

A hosting component for SwiftUI views.

HostProps

`children`

iOS

tvOS

Type: ReactNode

`colorScheme`

iOS

tvOS

Optional • Literal type: string

The color scheme of the host view.

Acceptable values are: 'light' | 'dark'

`ignoreSafeArea`

iOS

tvOS

Optional • Literal type: string

Controls which safe area regions the SwiftUI hosting view should ignore.

'all' - ignores all safe area insets, including the keyboard.
'container' - ignores only the container safe area (notch, home indicator, status and navigation bars). The keyboard safe area still applies.
'keyboard' - ignores only the keyboard safe area.

Acceptable values are: 'container' | 'all' | 'keyboard'

`layoutDirection`

iOS

tvOS

Optional • Literal type: string

The layout direction for the SwiftUI content. Defaults to the current locale direction from I18nManager.

Acceptable values are: 'leftToRight' | 'rightToLeft'

`matchContents`

iOS

tvOS

Optional • Literal type: union • Default: false

When true, the host view will update its size in the React Native view tree to match the content's layout from SwiftUI. Can be only set once on mount.

Acceptable values are: boolean | { horizontal: boolean, vertical: boolean }

`onLayoutContent`

iOS

tvOS

Optional • Type:

(event: {
  nativeEvent: {
  height: number, 
  width: number
}
}) => void

Callback function that is triggered when the SwiftUI content completes its layout. Provides the current dimensions of the content, which may change as the content updates.

`pointerEvents`

iOS

tvOS

Optional • Literal type: string

Acceptable values are: 'auto' | 'box-none' | 'none' | 'box-only'

`seedColor`

iOS

tvOS

Optional • Type: ColorValue

Seed color applied to the SwiftUI content as its tint. It propagates through the SwiftUI environment to theme interactive elements (buttons, switches, sliders, and similar controls) rendered by the children.

`style`

iOS

tvOS

Optional • Type: StyleProp<ViewStyle>

`useViewportSizeMeasurement`

iOS

tvOS

Optional • Type: boolean • Default: false

When true and no explicit size is provided, the host will use the viewport size as the proposed size for SwiftUI layout. This is particularly useful for SwiftUI views that need to fill their available space, such as Form.

Inherited props

CommonViewModifierProps