Windows下使用AndroidStudio+ReactNative开发Android应用

一、环境配置

1、其他环境

如果之前有用 AndroidStudio开发过安卓应用， Java环境和AndroidSDK都应该安装过了，否则需要安装一下。

另外需要安装 Node.js(后面需要使用npm)。

2、安装react-native

1) 直接使用npm安装

在cmd命令工具中执行以下命令，注意并非 install react-native，装了react-native在后面init项目的时候会报错，需要卸掉再重装。

npm install -g react-native-cli

2) 先clone代码再npm安装

git clone https://github.com/facebook/react-native.git

代码clone成功后，进入目录react-native-cli下，例如我的是 F:\opensource\react-native\react-native-cli，输入命令行：

npm install -g

安装好之后，可以命令行下就有 react-native命令了

二、创建*ReactNative项目*

命令行：

react-native init HelloAndroid

该命令会去拉取下载ReactNative源代码和相关依赖组件，然后创建一个包含了ios和android的项目:

在AndroidStudio上打开HelloAndroid/android目录，等待gradle构建完毕后运行HelloAndroid程序（稍久），可以看到以下ReactNatibe经典报错UI：

06-15 11:27:15.440 4649-4649/com.helloandroid E/unknown:React: Exception in native call from JS
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:860)
    at com.facebook.react.ReactInstanceManagerImpl.access$700(ReactInstanceManagerImpl.java:98)
    at com.facebook.react.ReactInstanceManagerImpl$ReactContextInitAsyncTask.doInBackground(ReactInstanceManagerImpl.java:194)
    at com.facebook.react.ReactInstanceManagerImpl$ReactContextInitAsyncTask.doInBackground(ReactInstanceManagerImpl.java:177)
    at android.os.AsyncTask$2.call(AsyncTask.java:288)
    at java.util.concurrent.FutureTask.run(FutureTask.java:237)
    at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
    at java.lang.Thread.run(Thread.java:841)
 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:831)
        ... 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
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.bridge.ReactBridge.loadScriptFromAssets(Native Method)
    at com.facebook.react.bridge.JSBundleLoader$1.loadScript(JSBundleLoader.java:32)
    at com.facebook.react.bridge.CatalystInstanceImpl.runJSBundle(CatalystInstanceImpl.java:148)
    at com.facebook.react.ReactInstanceManagerImpl$4.call(ReactInstanceManagerImpl.java:851)
    at com.facebook.react.ReactInstanceManagerImpl$4.call(ReactInstanceManagerImpl.java:832)
    at com.facebook.react.bridge.queue.MessageQueueThreadImpl$1.run(MessageQueueThreadImpl.java:73)
    at android.os.Handler.handleCallback(Handler.java:733)
    at android.os.Handler.dispatchMessage(Handler.java:95)
    at com.facebook.react.bridge.queue.MessageQueueThreadHandler.dispatchMessage(MessageQueueThreadHandler.java:31)
    at android.os.Looper.loop(Looper.java:136)
    at com.facebook.react.bridge.queue.MessageQueueThreadImpl$3.run(MessageQueueThreadImpl.java:197)
        ... 1 more

这是因为我们还未启动react-native的服务。

命令行中进入项目目录，输入react-native start进行构建，等待一段时间。

react-native start

注意这里不是使用run-android，run-android适用于直接在机器上运行调试app。

构建完毕，在浏览器中访问 http://localhost:8081/index.android.bundle?platform=android，如果可以访问表示服务器端已经可以了。

我们摇一摇手机，点击 Dev Settings后，点击 Debug server host & port for device,设置IP和端口。

这里的IP是电脑的IP，端口号固定8081。

设置完成后，回到空白页面，再次摇一摇手机，选择Reload JS，程序就运行起来，出现Welcome to React Native！

这个信息是在项目目录下 index.android.js里的，可以打开看看：

class HelloAndroid extends Component {
  render() {
    return (
      <View style={styles.container}>
        <Text style={styles.welcome}>
          Welcome to React Native!
        </Text>
        <Text style={styles.instructions}>
          To get started, edit index.android.js
        </Text>
        <Text style={styles.instructions}>
          Shake or press menu button for dev menu
        </Text>
      </View>
    );
  }
}