如何在连接互联网时运行服务？

Question

您好我是android的新手，我几乎完成了我的应用程序。但我现在坚持这个问题。我想运行一项仅在互联网连接或断开连接时才能运行的服务。我使用了Brodcast接收器，并在应用程序的活动中注册了brodcast。但是，当我尝试app被杀时它不起作用，接收器被调用，但它显示没有连接互联网。

广播接收器：

public class ImageDownloadReceiver extends BroadcastReceiver {

public static boolean isConnected(Context context){
    ConnectivityManager
            cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
    return activeNetwork != null
            && activeNetwork.isConnectedOrConnecting();
}


@Override
public void onReceive(Context context, Intent intent) {
    Log.i("Info", "onReceive in ImageDownloadReceiver get called ... ");

    if(isConnected(context)){
        Log.i("Info", "Internet connected !!!...Service starts ... ");
        Intent myService = new Intent(context, ImagesDownloadService.class);
        context.startService(myService);
    }else{
        Log.i("Info", "Internet disconnected !!!...Service stops ... ");
        Intent myService = new Intent(context, ImagesDownloadService.class);
        context.stopService(myService);
    }
}
}

表现：

    <receiver
        android:name=".receiver.ImageDownloadReceiver"
        android:enabled="true"
        android:exported="true"
        android:label="RestartServiceWhenStopped">
        <intent-filter>
            <action android:name="com.example.app.RestartImageDownloadService"/>
            <action
                android:name="android.net.conn.CONNECTIVITY_CHANGE" />
            <action android:name="android.net.wifi.WIFI_STATE_CHANGED" />
            <action android:name="android.net.wifi.STATE_CHANGE" />
        </intent-filter>
    </receiver>