我的火力基地：
public class BackgroundService extends Service implements OnCompletionListener
{
MediaPlayer mediaPlayer;
private String STREAM_URL;
final String textSource = "http://audiophileradio.stream/Ip.txt";
@Override
public IBinder onBind(Intent intent) {
return null;
}
@Override
public void onCreate()
{
}
@Override
public int onStartCommand(Intent intent, int flags, int startId)
{
new MyTask().execute();
return START_STICKY;
}
public void onDestroy() {
if (mediaPlayer.isPlaying()) {
mediaPlayer.stop();
}
mediaPlayer.release();
}
public void onCompletion(MediaPlayer _mediaPlayer) {
stopSelf();
}
@Override
public boolean onUnbind(Intent intent)
{
return super.onUnbind(intent);
}
private class MyTask extends AsyncTask<Void, Void, String>
{
String textResult;
@Override
protected String doInBackground(Void... params) {
URL textUrl;
try {
textUrl = new URL(textSource);
BufferedReader bufferReader
= new BufferedReader(new InputStreamReader(textUrl.openStream()));
String StringBuffer;
String stringText = "";
while ((StringBuffer = bufferReader.readLine()) != null) {
stringText += StringBuffer;
}
bufferReader.close();
textResult = stringText;
return textResult;
} catch (MalformedURLException e) {
e.printStackTrace();
textResult = e.toString();
} catch (IOException e) {
e.printStackTrace();
textResult = e.toString();
}
return null;
}
@Override
protected void onPostExecute(String result) {
Log.d("DebugTag", "Value: " + textResult);
super.onPostExecute(result);
SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(BackgroundService.this);
String radio = sharedPreferences.getString("station", "8000");
if (radio != null)
{
STREAM_URL += ":" + radio;
}
mediaPlayer = new MediaPlayer();
if (!mediaPlayer.isPlaying())
{
try
{
mediaPlayer.reset();
mediaPlayer.setDataSource(STREAM_URL);
mediaPlayer.prepareAsync();
mediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener()
{
@Override
public void onPrepared(MediaPlayer mp)
{
mediaPlayer.start();
}
});
} catch (IOException e)
{
e.printStackTrace();
}
}
mediaPlayer.setOnCompletionListener(BackgroundService.this);
}
}
}
public class Main extends Fragment
{
private ImageButton buttonPlay;
private MediaPlayer mPlayer;
Intent playbackServiceIntent;
private SeekBar volumeSeekbar = null;
private AudioManager audioManager = null;
View view;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState)
{
view = inflater.inflate(R.layout.fragment_main,container,false);
buttonPlay = (ImageButton) view.findViewById(R.id.buttonPlay);
mPlayer = new MediaPlayer();
initControls();
buttonPlay.setTag(1);
buttonPlay.setImageResource(R.drawable.play);
buttonPlay.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View view)
{
if (Integer.parseInt(buttonPlay.getTag().toString()) == 1)
{
buttonPlay.setImageResource(R.drawable.stop);
view.setTag(0);
getActivity().startService(playbackServiceIntent);
Log.e("Play", "onStop");
Toast.makeText(getActivity(), "Play", Toast.LENGTH_SHORT).show();
} else
{
buttonPlay.setImageResource(R.drawable.play);
view.setTag(1);
mPlayer.stop();
getActivity().stopService(playbackServiceIntent);
Log.e("Stop", "onPlay");
Toast.makeText(getActivity(), "Stop", Toast.LENGTH_SHORT).show();
}
}
});
playbackServiceIntent = new Intent(getActivity(), BackgroundService.class);
return view;
}
@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState)
{
super.onViewCreated(view, savedInstanceState);
getActivity().setTitle("Audiophileradio");
}
private void startService()
{
getActivity().startService(new Intent(getActivity(),BackgroundService.class));
}
private void stopService()
{
getActivity().stopService(new Intent(getActivity(),BackgroundService.class));
}
private void initControls()
{
try
{
volumeSeekbar = (SeekBar) view.findViewById(R.id.seekBar);
audioManager = (AudioManager) getActivity().getSystemService(Context.AUDIO_SERVICE);
volumeSeekbar.setMax(audioManager
.getStreamMaxVolume(AudioManager.STREAM_MUSIC));
volumeSeekbar.setProgress(audioManager
.getStreamVolume(AudioManager.STREAM_MUSIC));
//volumeSeekbar.setMax(100);
volumeSeekbar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener()
{
@Override
public void onStopTrackingTouch(SeekBar arg0)
{
}
@Override
public void onStartTrackingTouch(SeekBar arg0)
{
}
@Override
public void onProgressChanged(SeekBar arg0, int progress, boolean arg2)
{
audioManager.setStreamVolume(AudioManager.STREAM_MUSIC,
progress, 0);
//volume.setText("Volume : " + progress + "%");
}
});
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
我如何输出图像？ 我在component.ts中的代码
{
"hotel" : {
"-Kjgyamcup6ULm0Awa-1" : {
"complete" : "true",
"images" : {
"-Kjgyb6A2gRiDhwaWx-V" : {
"name" : "2.jpg",
"url" : "https://firebasestorage.googleapis.com/v0/b/teplo-31a17.appspot.com/o/hotel%2F-Kjgyamcup6ULm0Awa-1%2Fimages%2F2.jpg?alt=media&token=0faffb92-9bc5-44ce-9189-ee405137c3bf"
},
"-KjgybAKrkf3EzYxvgGD" : {
"name" : "4.jpg",
"url" : "https://firebasestorage.googleapis.com/v0/b/teplo-31a17.appspot.com/o/hotel%2F-Kjgyamcup6ULm0Awa-1%2Fimages%2F4.jpg?alt=media&token=bd7ebc47-b14d-46e5-a58d-01d647fcf95d"
}
},
"number" : "102",
"price" : "2500"
}, etc
和html
export class UserComponent implements OnInit {
hotelNumbers: FirebaseListObservable<any[]>;
constructor(private af: AngularFire) {
this.hotelNumbers = af.database.list('/hotel');
}
ngOnInit() {
}
}
如何输出图像（* ngFor =“hotel.number.images | async”的图像） - 没有工作
答案 0 :(得分：1)
可以解决问题如下：
通过建议rmekarni编辑我的数据库：
编辑component.ts文件
constructor(private af: AngularFire) {
this.hotelNumbers = af.database.list('/hotel').map((myhotels) =>{
return myhotels.map(myhotel =>{
myhotel.img = af.database.list('/images/' + myhotel.$key);
return myhotel;
});
});
}
编辑html文件
<div *ngFor="let myhotel of hotels | async">
<p>{{myhotel.number}}</p>
<div *ngFor="let img of myhotel.img | async">
<img src="{{img.url}}">
</div>
</div>
答案 1 :(得分：0)
this.hotels = af.database.list('/hotel');
Firebase很棒，因为它将一个observable与一个数组合并。因此，您可以将af.database.list('/hotel')返回的observable视为数组，并在其上执行带有异步管道的ngFor：
<div *ngFor="let hotel of hotels | async">
<p>{{hotel.images}}</p>
etc
</div>
这是因为hotel是一个项目（JSON对象中的一个键），它有images属性（价格，完整等）
如果您想迭代所有酒店的图片，那么您的数据结构是错误的。您应该对其进行非规范化并使数据结构变平。这里有一篇关于它的优秀文章，你必须阅读它！ Firebase doc - structure your database
如果您真的想保留该数据结构，则无法使用异步管道直接迭代图像。您有订阅您的酒店并通过回调获取图像嵌套对象。我认为你必须通过用Object.keys(json).forEach(key => json[key]...);迭代你的嵌套json来创建一个数组，然后在ngFor指令中使用该数组......