Expo BlurView
一个会模糊视图下方所有内容的 React 组件。
For the complete documentation index, see llms.txt. Use this file to discover all available pages.
一个会模糊其下方所有内容的 React 组件。它通常用于导航栏、标签栏和模态框。
已知问题
当 BlurView 在动态内容(例如 FlatList)渲染之前先被渲染时,模糊效果不会更新。要修复此问题,请确保 BlurView 在动态内容组件之后渲染。例如:
<View> <FlatList /> <BlurView /> </View>
安装
- npx expo install expo-blurIf you are installing this in an existing React Native app, make sure to install expo in your project.
用法
基础的仅 iOS 和 Web 的 BlurView 用法
这是创建 BlurView 的旧方式,这种方式只会在 iOS 上产生模糊效果。在 Android 上,这将显示为一个带有半透明背景的视图。
import { Text, StyleSheet, View } from 'react-native'; import { BlurView } from 'expo-blur'; export default function App() { const text = 'Hello, my container is blurring contents underneath!'; return ( <View style={styles.container}> <View style={styles.background}> {[...Array(20).keys()].map(i => ( <View key={`box-${i}`} style={[styles.box, i % 2 === 1 ? styles.boxOdd : styles.boxEven]} /> ))} </View> <BlurView intensity={100} style={styles.blurContainer}> <Text style={styles.text}>{text}</Text> </BlurView> <BlurView intensity={80} tint="light" style={styles.blurContainer}> <Text style={styles.text}>{text}</Text> </BlurView> <BlurView intensity={90} tint="dark" style={styles.blurContainer}> <Text style={[styles.text, { color: '#fff' }]}>{text}</Text> </BlurView> </View> ); } const styles = StyleSheet.create({ container: { flex: 1, }, blurContainer: { flex: 1, padding: 20, margin: 16, textAlign: 'center', justifyContent: 'center', overflow: 'hidden', borderRadius: 20, }, background: { flex: 1, flexWrap: 'wrap', ...StyleSheet.absoluteFill, }, box: { width: '25%', height: '20%', }, boxEven: { backgroundColor: 'orangered', }, boxOdd: { backgroundColor: 'gold', }, text: { fontSize: 24, fontWeight: '600', }, });
支持 Android 的基础 BlurView 用法
要在 Android 上模糊视图的背景,请将需要模糊的内容包裹在 BlurTargetView 组件中,并将其 ref 传递给 BlurView。
注意: 请注意,只要所有BlurView都位于单个BlurTargetView的边界范围内,你就可以让多个BlurView共用同一个BlurTargetView。这比创建多个BlurTargetView更高效。
import { BlurView, BlurTargetView } from 'expo-blur'; import { useRef } from 'react'; import { Text, StyleSheet, View } from 'react-native'; export default function App() { const targetRef = useRef<View | null>(null); const text = 'Hello, my container is blurring contents underneath!'; return ( <View style={styles.container}> <BlurTargetView ref={targetRef} style={styles.background}> {[...Array(20).keys()].map(i => ( <View key={`box-${i}`} style={[styles.box, i % 2 === 1 ? styles.boxOdd : styles.boxEven]} /> ))} </BlurTargetView> <BlurView blurTarget={targetRef} intensity={100} style={styles.blurContainer} blurMethod="dimezisBlurView"> <Text style={styles.text}>{text}</Text> </BlurView> <BlurView blurTarget={targetRef} intensity={80} tint="light" style={styles.blurContainer} blurMethod="dimezisBlurView"> <Text style={styles.text}>{text}</Text> </BlurView> <BlurView blurTarget={targetRef} intensity={90} tint="dark" style={styles.blurContainer} blurMethod="dimezisBlurView"> <Text style={[styles.text, { color: '#fff' }]}>{text}</Text> </BlurView> </View> ); } const styles = StyleSheet.create({ container: { flex: 1, }, blurContainer: { flex: 1, padding: 20, margin: 16, textAlign: 'center', justifyContent: 'center', overflow: 'hidden', borderRadius: 20, }, background: { flex: 1, flexWrap: 'wrap', ...StyleSheet.absoluteFill, }, box: { width: '25%', height: '20%', }, boxEven: { backgroundColor: 'orangered', }, boxOdd: { backgroundColor: 'gold', }, text: { fontSize: 24, fontWeight: '600', }, });
Android 支持
模糊功能在 Android 上是稳定的。迁移时有几点需要注意:
API
要在 Android 上模糊视图的背景,请将需要模糊的内容包裹在 BlurTargetView 组件中,并将其 ref 传递给 BlurView。你可以在 用法 部分查看示例。
性能
模糊效果只能通过使用 RenderNode Android API 高效实现,该 API 由 Android SDK 31(Android 12.0)引入。因此,在较旧版本的 Android 上,expo-blur 会使用效率低得多的 RenderScript API。如果你想避免旧平台上的性能损耗,可以使用 dimezisBlurViewSdk31Plus BlurMethod,它只会在较新的 Android 版本上启用模糊,并在旧版本上回退到 none。
API
import { BlurView } from 'expo-blur';
Components
Type: React.Component<BlurViewProps, BlurViewState>
number • Default: 4A number by which the blur intensity will be divided on Android.
When using experimental blur methods on Android, the perceived blur intensity might differ from iOS at different intensity levels. This property can be used to fine tune it on Android to match it more closely with iOS.
A ref to a BlurTargetView, which this BlurView will blur as its background.
number • Default: 50A number from 1 to 100 to control the intensity of the blur effect.
You can animate this property using react-native-reanimated.
BlurTint • Default: 'default'A tint mode which will be applied to the view.
Type: React.Element<BlurTargetViewProps>
Types
Literal Type: string
Blur method to use on Android.
-
'none'- Renders a semi-transparent view instead of rendering a blur effect. -
'dimezisBlurView'- Uses a native blur view implementation based on BlurView library. This method may lead to decreased performance on Android SDK 30 and below. -
'dimezisBlurViewSdk31Plus'- Uses a native blur view implementation based on BlurView library on Android SDK 31 and above, for older versions of Android falls back to 'none'. This is due to performance limitations on older versions of Android, see the performance section to learn more.
Acceptable values are: 'none' | 'dimezisBlurView' | 'dimezisBlurViewSdk31Plus'
Literal Type: string
Acceptable values are: 'light' | 'dark' | 'default' | 'extraLight' | 'regular' | 'prominent' | 'systemUltraThinMaterial' | 'systemThinMaterial' | 'systemMaterial' | 'systemThickMaterial' | 'systemChromeMaterial' | 'systemUltraThinMaterialLight' | 'systemThinMaterialLight' | 'systemMaterialLight' | 'systemThickMaterialLight' | 'systemChromeMaterialLight' | 'systemUltraThinMaterialDark' | 'systemThinMaterialDark' | 'systemMaterialDark' | 'systemThickMaterialDark' | 'systemChromeMaterialDark'
将 borderRadius 与 BlurView 一起使用
在 Android 和 iOS 上使用 BlurView 时,如果显式提供 borderRadius 属性,它不会生效。要修复此问题,可以使用 overflow: 'hidden' 样式,因为 BlurView 会继承 <View> 的属性。示例请参见 用法。