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MaskedView
与 @react-native-masked-view/masked-view 兼容的遮罩视图。
一个具有与 @react-native-masked-view/masked-view 兼容的 API 的 MaskedView 组件。maskElement 的不透明像素显示其背后的遮罩内容;透明像素隐藏它。
🌐 A MaskedView component with an API compatible with @react-native-masked-view/masked-view. The opaque pixels of maskElement reveal the masked content behind it; transparent pixels hide it.
在底层,这个组件将任意 React Native 子组件桥接到平台特定的 @expo/ui 掩码原语中:
🌐 Under the hood this component bridges arbitrary React Native children into the platform-specific @expo/ui masking primitives:
- Android:使用
BlendMode.DstIn的 Jetpack Compose 图形层合成。 - iOS:SwiftUI
.mask修改器。
安装
🌐 Installation
- npx expo install @expo/uiIf you are installing this in an existing React Native app, make sure to install expo in your project.
从 @react-native-masked-view/masked-view 迁移
🌐 Migrating from @react-native-masked-view/masked-view
- 将导入从
import MaskedView from '@react-native-masked-view/masked-view'更新为import { MaskedView } from '@expo/ui/community/masked-view'。 androidRenderingMode属性不受支持。基于 Compose 的实现始终使用离屏图形层,因此该属性没有对应项,并且在公共类型中被省略。- Web 未实现。在 Web 上,子元素会以未遮罩的方式渲染,并且会记录一次性控制台警告。对于 Web 目标,优先使用适合你特定情况的 CSS 原语:
- 渐变文本 — 使用
background-clip: text和color: 'transparent'以及 CSS 渐变/图片作为背景。 - Alpha 淡入淡出 —
mask-image: linear-gradient(...)(或WebkitMaskImage)直接在内容视图上。 - 形状蒙版(圆形、圆角矩形等)——
clip-path: circle(...)/inset(...)/path(...),或border-radius+overflow: 'hidden'。
- 渐变文本 — 使用
基本用法
🌐 Basic usage
import { MaskedView } from '@expo/ui/community/masked-view'; import { StyleSheet, Text, View } from 'react-native'; export default function MaskedViewExample() { return ( <MaskedView style={{ width: 300, height: 80 }} maskElement={ <View style={{ flex: 1, alignItems: 'center', justifyContent: 'center' }}> <Text style={{ fontSize: 64, fontWeight: 'bold' }}>EXPO</Text> </View> }> <View style={[ StyleSheet.absoluteFill, { experimental_backgroundImage: 'linear-gradient(135deg, #FF3B30, #FF9500, #FFCC00, #34C759, #007AFF, #AF52DE)', }, ]} /> </MaskedView> ); }
Alpha 淡化遮罩
🌐 Alpha-fade mask
只有 maskElement 的 alpha 通道才重要:不透明像素显示内容,透明像素隐藏内容。使用一个从不透明到透明的 LinearGradient(来自 expo-linear-gradient)——例如将 'black' 到下面的 'transparent' ——沿某一轴淡出内容。
🌐 Only the alpha channel of the maskElement matters: opaque pixels reveal content, transparent pixels hide it. Use a LinearGradient (from expo-linear-gradient) that goes from opaque to transparent — 'black' (for example) to 'transparent' below — to fade content out along an axis.
import { MaskedView } from '@expo/ui/community/masked-view'; import { LinearGradient } from 'expo-linear-gradient'; import { StyleSheet, View } from 'react-native'; export default function AlphaFadeExample() { return ( <MaskedView style={{ width: 300, height: 80, flexDirection: 'row' }} maskElement={ <LinearGradient colors={['black', 'transparent']} start={{ x: 0, y: 0 }} end={{ x: 1, y: 0 }} style={StyleSheet.absoluteFill} /> }> <View style={{ flex: 1, backgroundColor: '#3D5A80' }} /> <View style={{ flex: 1, backgroundColor: '#DAA520' }} /> <View style={{ flex: 1, backgroundColor: '#E07A5F' }} /> </MaskedView> ); }
应用接口
🌐 API
import { MaskedView } from '@expo/ui/community/masked-view';
Component
Type: React.Element<MaskedViewProps>
Renders children with the alpha channel of maskElement applied as a mask:
opaque pixels of maskElement reveal children, transparent pixels hide them.
API-compatible with @react-native-masked-view/masked-view.
Drop-in props for @react-native-masked-view/masked-view's MaskedView.