1.在原有 Android 项目中嵌入 ReactNative 模块

ReactNative的发展已经进入了很多开发者视野，作为一名原生开发者更是对 RN 充满了无限的好奇和期待,
本节将详细讲述如何将一个原生的 Android App 项目嵌入最新的 RN 模块

1. 准备开始

1.  一个已有的 Android 原生项目
2. 已经配置好的原生 Android 开发环境和 node.js已经 RN 环境
3. 改造之后的流程图 

package_json

3. 工程目录下创建 index.android.js 由于是测试代码直接 Copy FaceBook 的源码

/**
 * Sample React Native App
 * https://github.com/facebook/react-native
 * @flow
 */

import React, { Component } from 'react';
import {
  AppRegistry,
  StyleSheet,
  Text,
  View
} from 'react-native';

class AwesomeProject extends Component {
  render() {
    return (
      <View style={styles.container}>
        <Text style={styles.welcome}>
          Welcome to React Native!
        </Text>
        <Text style={styles.instructions}>
          我是 原生项目嵌入的 ReactNative
        </Text>
        <Text style={styles.instructions}>
          Press Cmd+R to reload,{'\n'}
          Cmd+D or shake for dev menu
        </Text>
      </View>
    );
  }
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
    backgroundColor: '#F5FCFF',
  },
  welcome: {
    fontSize: 20,
    textAlign: 'center',
    margin: 10,
  },
  instructions: {
    textAlign: 'center',
    color: '#333333',
    marginBottom: 5,
  },
});

AppRegistry.registerComponent('myreactactivity', () => AwesomeProject);

注意：此处需要修改注册的入口 保持一致，我的是 my_react_activity

4.检查以上所有步骤，有无遗漏，如果正常，接下来就可以顺利的运行你的混合 APP 了，如果还不行，你需要检查你的姿势是否正确？

运行你的 APP

1. 在项目的工程路径运行以下命令来启动你的开发服务器

react-native start

或者执行

npm start

2. android studio 调试你的 APP
3. 演示效果图

===================

错误解决：

  Process: com.allen.reactapp, PID: 20469
java.lang.RuntimeException: java.util.concurrent.ExecutionException: java.lang.RuntimeException: Could not connect to development server.
Try the following to fix the issue:
Ensure that the packager server is running
Ensure that your device/emulator is connected to your machine and has USB debugging enabled - run 'adb devices' to see a list of connected devices
If you're on a physical device connected to the same machine, run 'adb reverse tcp:8081 tcp:8081' to forward requests from your device
If your device is on the same Wi-Fi network, set 'Debug server host & port for device' in 'Dev settings' to y
at com.facebook.react.ReactInstanceManagerImpl.createReactContext(ReactInstanceManagerImpl.java:911)
at com.facebook.react.ReactInstanceManagerImpl.access$700(ReactInstanceManagerImpl.java:100)
at com.facebook.react.ReactInstanceManagerImpl$ReactContextInitAsyncTask.doInBackground(ReactInstanceManagerImpl.java:197)
at com.facebook.react.ReactInstanceManagerImpl$ReactContextInitAsyncTask.doInBackground(ReactInstanceManagerImpl.java:180)
at android.os.AsyncTask$2.call(AsyncTask.java:295)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:234)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1113)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:588)
at java.lang.Thread.run(Thread.java:818)
Caused by: java.util.concurrent.ExecutionException: java.lang.RuntimeException: Could not connect to development server.
Try the following to fix the issue:
Ensure that the packager server is running
Ensure that your device/emulator is connected to your machine and has USB debugging enabled - run 'adb devices' to see a list of connected devices
If you're on a physical device connected to the same machine, run 'adb reverse tcp:8081 tcp:8081' to forward requests from your device
If your device is on the same Wi-Fi network, set 'Debug server host & port for device' in 'Dev settings' to y
at com.facebook.react.common.futures.SimpleSettableFuture.get(SimpleSettableFuture.java:68)
at com.facebook.react.ReactInstanceManagerImpl.createReactContext(ReactInstanceManagerImpl.java:882)
    ... 9 more
Caused by: java.lang.RuntimeException: Could not connect to development server.
Try the following to fix the issue:
Ensure that the packager server is running
Ensure that your device/emulator is connected to your machine and has USB debugging enabled - run 'adb devices' to see a list of connected devices

解决办法：
.setUseDeveloperSupport(true) 调试模式下,建议直接写成 true 吧,

签名打包混合 APP
1. 将 js 文件存入 bundle 一起打包
执行命令：

curl -k "http://localhost:8081/index.android.bundle"> reactapp/src/main/assets/index.android.bundle

执行完命令成功，在 assets目录应该看到 index.android.bundle文件

Android studio 执行打包过程，作为一名 Android 老司机我就不再具体描述了

原 Android 移植 React Native 项目地址