2019-04-10Android跟RN通信的几种方式

方式一：原生主动向RN发送数据
第一步：在MainApplication中 添加Package 它实现了ReactApplication接口代码如下：
private final ReactNativeHost mReactNativeHost = new ReactNativeHost(this) {

    @Override
    protected String getJSBundleFile() {
        return CodePush.getJSBundleFile();
    }


    @Override
    protected List<ReactPackage> getPackages() {
        return Arrays.<ReactPackage>asList(
                new MainReactPackage(),
                updateDownloadPackage, //这里以updateDownloadPackage为例子
                new RNGestureHandlerPackage(),
                new CodePush(getResources().getString(R.string.reactNativeCodePush_androidDeploymentKey), getApplicationContext(), BuildConfig.DEBUG)

        );
    }

    @Override
    protected String getJSMainModuleName() {
        return "index";
    }

    @Override
    public boolean getUseDeveloperSupport() {
        return BuildConfig.DEBUG;
    }
};

接下来看看Packager的代码例子
```java
public class UpdateDownloadPackage implements ReactPackage {


    @Override
    public List<NativeModule> createNativeModules(ReactApplicationContext reactContext) {
        List<NativeModule> modules=new ArrayList<>();
        modules.add(new UpdateDownloadModule(reactContext));
        return modules;
    }

    @Override
    public List<ViewManager> createViewManagers(ReactApplicationContext reactContext) {
        return Collections.emptyList();
    }
}

接下来的重点还是在Module中，代码如下：

public class UpdateDownloadModule extends ReactContextBaseJavaModule {

    public static final String MODULE_NAME="updateDownloadModule";
    public static final String EVENT_NAME = "nativeCallRn";
    public ReactApplicationContext context ;

    public UpdateDownloadModule(ReactApplicationContext reactContext) {
        super(reactContext);
        this.context = reactContext;
    }

    @Override
    public String getName() {
        return MODULE_NAME;
    }
  
   //新版RN多了一个initalize方法 ，如果是老版本没有这个方法可以直接在MainActivity中实现
    @Override
    public void initialize() {
        Log.i("gdchent","module_initialize");
        nativeCallRn("需要的数据"); //这里可以传json对象
    }

    @Override
    public boolean canOverrideExistingModule() {
        return false;
    }

    @Override
    public void onCatalystInstanceDestroy() {

    }

    /**
     * Native调用RN
     * @param msg
     */
    public void nativeCallRn(String msg) {
        Log.i("gdchent","apkUrl"+msg);
        context.getJSModule(DeviceEventManagerModule.RCTDeviceEventEmitter.class)
                .emit(EVENT_NAME,msg);

    }
}

RN端接收数据：

import { DeviceEventEmitter } from 'react-native';
  /**
    * 接收原生调用
    */
   componentDidMount() {

       DeviceEventEmitter.addListener('nativeCallRn',(msg)=>{
            title = "React Native界面,收到数据：" + global.patchImgNames;
            ToastAndroid.show("发送成功", ToastAndroid.SHORT);
       })
   }

方式2：调用原生代码跳转到原生界面

...详情参见GitHub传送门
https://github.com/gdchent/NavigationApp