Reference version

This is documentation for the next SDK version. For up-to-date documentation, see the latest version (SDK 55).

Expo Brownfield

用于将 Expo 集成到现有原生应用中的工具包和 API。

Android
iOS

For the complete documentation index, see llms.txt. Use this Use this file to discover all available pages.

expo-brownfield 是一个工具包,用于向现有的原生 Android 和 iOS 应用中添加 React Native 视图。它提供:

  • 内置 API,用于原生应用和 React Native 应用之间的双向通信与导航
  • 配置插件,用于在你的 Expo 项目中自动设置 brownfield 目标
  • CLI,用于将构建产物发布到 Maven 仓库(Android)和 XCFrameworks(iOS)

安装

Terminal
npx expo install expo-brownfield

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

使用

通信 API

通信 API 使原生(宿主)应用与 React Native 之间能够进行基于消息的双向通信。

从 React Native 向原生发送消息

import * as Brownfield from 'expo-brownfield'; Brownfield.sendMessage({ type: 'MyMessage', data: { language: 'TypeScript', expo: true, platforms: ['android', 'ios'], }, });

在 React Native 中接收来自原生的消息

import * as Brownfield, { type MessageEvent } from 'expo-brownfield'; import { useEffect } from 'react'; function MyComponent() { useEffect(() => { const handleMessage = (event: MessageEvent) => { console.log('收到消息:', event); }; Brownfield.addMessageListener(handleMessage); return () => { Brownfield.removeMessageListener(handleMessage); }; }, []); // ... }

从原生向 React Native 发送消息

import expo.modules.brownfield.BrownfieldMessaging BrownfieldMessaging.sendMessage(mapOf( "type" to "MyAndroidMessage", "timestamp" to System.currentTimeMillis(), "data" to mapOf( "platform" to "android" ) ))
import ExpoBrownfield BrownfieldMessaging.sendMessage([ "type": "MyIOSMessage", "timestamp": Date().timeIntervalSince1970, "data": [ "platform": "ios" ] ])

在原生中接收来自 React Native 的消息

import expo.modules.brownfield.BrownfieldMessaging val listenerId = BrownfieldMessaging.addListener { event -> println("来自 React Native 的消息:$event") } // 稍后,移除监听器: BrownfieldMessaging.removeListener(listenerId)
import ExpoBrownfield let listenerId = BrownfieldMessaging.addListener { message in print("来自 React Native 的消息:\(message)") } // 稍后,移除监听器: BrownfieldMessaging.removeListener(id: listenerId)

在应用配置中进行配置

expo-brownfield 包提供了一个配置插件,可在使用连续原生生成(CNG)时用于配置 brownfield 集成。此插件允许你自定义 Expo 项目如何被打包并集成到现有的原生应用中。

Example app.json with config plugin

app.json
{ "expo": { "plugins": [ [ "expo-brownfield", { "ios": { "targetName": "MyBrownfieldTarget", "bundleIdentifier": "com.example.brownfield" }, "android": { "group": "com.example", "libraryName": "brownfield", "package": "com.example.brownfield", "version": "1.0.0" } } ] ] } }

Configurable properties

NameDefaultDescription
ios.targetName"<scheme>brownfield" or "<slug>brownfield"
Only for:
iOS

brownfield 集成的 Xcode 目标名称。这将用于在你的 Xcode 项目中为 React Native 代码创建一个单独的目标。

ios.bundleIdentifier"<ios.bundleIdentifier base>.<targetName>" or "com.example.<targetName>"
Only for:
iOS

brownfield 目标的包标识符。这应该是唯一的,并且不同于你的主应用包标识符。

ios.buildReactNativeFromSourcefalse
Only for:
iOS

从源码构建 React Native,而不是使用预构建框架。开启此项会显著增加构建时间。

android.group"<package without last segment>"
Only for:
Android

生成的 Android 库的 Maven group ID。发布该库到 Maven 仓库时会使用它。

android.libraryName"brownfield"
Only for:
Android

生成的 Android 库模块名称。

android.package"<android.package>.brownfield" or "com.example.brownfield"
Only for:
Android

生成的 Android 库代码的 Java/Kotlin 包名。

android.version"1.0.0"
Only for:
Android

生成的 Android 库的版本字符串。发布到 Maven 仓库时会使用它。

android.publishing[{ type: "localMaven" }]
Only for:
Android

生成的 Android 库的发布配置。支持 localMavenlocalDirectoryremotePublicremotePrivate 发布类型。每种类型都有不同的配置选项,用于指定库发布到哪里以及如何发布。

CLI

expo-brownfield 库包含一个 CLI,用于构建并发布到 Maven 仓库(Android)和 XCFrameworks(iOS)。

Terminal
npx expo-brownfield [command] [options]

命令

build:android

构建并将 brownfield 库及其依赖项发布到 Maven 仓库。

Terminal
npx expo-brownfield build:android [options]
选项描述
-d, --debug以调试模式构建
-r, --release以发布模式构建
-a, --all同时以调试和发布模式构建(默认)
-l, --library指定 brownfield 库名称
--repo, --repository指定要发布到的 Maven 仓库
-t, --task指定要运行的 Gradle 发布任务
--verbose包含子进程的所有日志

build:ios

构建 brownfield XCFramework,并将 Hermes XCFramework 复制到产物目录。

Terminal
npx expo-brownfield build:ios [options]
选项描述
-d, --debug以调试模式构建
-r, --release以发布模式构建(默认)
-a, --artifacts产物目录的路径(默认:./artifacts
-s, --scheme要构建的 Xcode scheme
-x, --xcworkspaceXcode workspace 路径
-p, --package将产物作为 Swift Package 交付(可选名称)
--verbose包含子进程的所有日志

tasks:android

列出所有可用的发布任务和 Maven 仓库。

Terminal
npx expo-brownfield tasks:android

API

import * as Brownfield from 'expo-brownfield';

Hooks

useSharedState(key, initialValue)

Android
iOS
ParameterTypeDescription
keystring

The key to get the value for.

initialValue(optional)T

The initial value to be used if the shared state is not set.


Hook to observe and set the value of shared state for a given key. Provides a synchronous API similar to useState.

Returns:
[T | undefined, (value: T | (prev: T | undefined) => T) => void]

A tuple containing the value and a function to set the value.

Methods

Brownfield.deleteSharedState(key)

Android
iOS
ParameterTypeDescription
keystring

The key to delete the shared state for.


Deletes the shared state for a given key.

Returns:
void

Brownfield.getMessageListenerCount()

Android
iOS

Gets the number of registered message listeners.

Returns:
number

The number of active message listeners.

Brownfield.getSharedStateValue(key)

Android
iOS
ParameterTypeDescription
keystring

The key to get the value for.


Gets the value of shared state for a given key.

Returns:
T | undefined

Brownfield.popToNative(animated)

Android
iOS
ParameterTypeDescription
animated(optional)boolean

Whether to animate the transition (iOS only). Defaults to false.

Default:false

Navigates back to the native part of the app, dismissing the React Native view.

Returns:
void

Brownfield.sendMessage(message)

Android
iOS
ParameterTypeDescription
messageRecord<string, any>

A dictionary containing the message payload to send to native.


Sends a message to the native side of the app. The message can be received by setting up a listener in the native code.

Returns:
void

Brownfield.setNativeBackEnabled(enabled)

Android
iOS
ParameterTypeDescription
enabledboolean

Whether to enable native back button handling.


Enables or disables the native back button behavior. When enabled, pressing the back button will navigate back to the native part of the app instead of performing the default React Navigation back action.

Returns:
void

Brownfield.setSharedStateValue(key, value)

Android
iOS
ParameterTypeDescription
keystring

The key to set the value for.

valueT

The value to be set.


Sets the value of shared state for a given key.

Returns:
void

Event Subscriptions

Brownfield.addMessageListener(listener)

Android
iOS
ParameterTypeDescription
listenerListener<MessageEvent>

A callback function that receives message events from native.


Adds a listener for messages sent from the native side of the app.

Returns:
EventSubscription

A subscription object that can be used to remove the listener.

Example

const subscription = addMessageListener((event) => { console.log('Received message from native:', event); }); // Later, to remove the listener: subscription.remove();

Brownfield.addSharedStateListener(key, callback)

Android
iOS
ParameterTypeDescription
keystring

The key to add the listener for.

callback(value: T | undefined) => void

The callback to be called when the shared state changes.


Adds a listener for changes to the shared state for a given key.

Returns:
EventSubscription

A subscription object that can be used to remove the listener.

Brownfield.removeAllMessageListeners()

Android
iOS

Removes all message listeners.

Returns:
void

Brownfield.removeMessageListener(listener)

Android
iOS
ParameterTypeDescription
listenerListener<MessageEvent>

The listener function to remove.


Removes a specific message listener.

Returns:
void

Interfaces

EventSubscription

Android
iOS

A subscription object that allows to conveniently remove an event listener from the emitter.

EventSubscription Methods

remove()

Android
iOS

Removes an event listener for which the subscription has been created. After calling this function, the listener will no longer receive any events from the emitter.

Returns:
void

Types

MessageEvent

Android
iOS

Type: Record<string, any>