服务在应用程序关闭时停止

Question

I am working on a wallpaper application in which i am setting a gallery of images on wallpaper with shuffle effect for 5 min, 10 min etc. I am using service for this task. My service works well when app remains in background, but service get stopped when app get stopped.This is my code for service class:

public class WallpaperService extends Service {
ArrayList<String> arrayList;int counter = 0;

boolean serviceStopped;

private IBinder binder = new WallpaperServiceBinder();

public WallpaperService() {
}

private Handler mHandler;

private Runnable updateRunnable = new Runnable() {
    @Override
    public void run() {
        if (serviceStopped == false)
        {
            createNotificationIcon();
        }
        queueRunnable();
    }
};

public class WallpaperServiceBinder extends Binder {
    public WallpaperService getService() {
        return WallpaperService.this;
    }
}

private void queueRunnable() {
    // 600000 : cada 10 minutos, comprueba si hay nuevas notificaciones y actualiza la
    // notification BAR
    mHandler.postDelayed(updateRunnable, 5000);
}

@Override
public int onStartCommand(Intent intent,int flag, int start_id){
    super.onStartCommand(intent,flag,start_id);
    arrayList = intent.getStringArrayListExtra("image_url");
    return START_STICKY;
}

@Override
public void onRebind(Intent intent) {
    Log.v("Service","in onRebind");
    super.onRebind(intent);
}

@Override
public IBinder onBind(Intent intent) {
    return binder;
}

@Override
public void onCreate() {
    serviceStopped = false;
    mHandler = new Handler();
    queueRunnable();
}

@Override
public void onStart(Intent intent, int startid) {

}

public void createNotificationIcon()
{
    counter += 1;
    Toast.makeText(this, "Hello", Toast.LENGTH_SHORT).show();
    Picasso.with(getApplicationContext()).load(arrayList.get(counter)).into(new Target() {
        @Override
        public void onBitmapLoaded(Bitmap bitmap, Picasso.LoadedFrom from) {
            try {
                final WallpaperManager wallpaperManager =
                        WallpaperManager.getInstance(getApplicationContext());
                wallpaperManager.setBitmap(bitmap);
                wallpaperManager.suggestDesiredDimensions(1080, 1920);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        @Override
        public void onBitmapFailed(Drawable errorDrawable) {

        }

        @Override
        public void onPrepareLoad(Drawable placeHolderDrawable) {
            //Here you should place a loading gif in the ImageView to
            //while image is being obtained.
        }
    });
}}

This is the code i am using to start service:

Intent intent = new Intent(CategoryActivity.this,WallpaperService.class);
            intent.putExtra("image_url",img_urls);
            intent.setAction(Constants.ACTION.STARTFOREGROUND_ACTION);
            startService(intent);
            bindService(intent,mServiceConnection, Context.BIND_AUTO_CREATE);

Answer 1

Important Fact about the bindService

If a component calls bindService() to create the service and onStartCommand() is not called, the service runs only as long as the component is bound to it. After the service is unbound from all of its clients, the system destroys it.

Try using Started Service

A started service is one that another component starts by calling startService(), which results in a call to the service's onStartCommand() method.

When a service is started, it has a lifecycle that's independent of the component that started it. The service can run in the background indefinitely, even if the component that started it is destroyed. As such, the service should stop itself when its job is complete by calling stopSelf(), or another component can stop it by calling stopService().

An application component such as an activity can start the service by calling startService() and passing an Intent that specifies the service and includes any data for the service to use. The service receives this Intent in the onStartCommand() method.

Handling onStartCommand

Notice that the onStartCommand() method must return an integer. The integer is a value that describes how the system should continue the service in the event that the system kills it. The default implementation for IntentService handles this for you, but you are able to modify it. The return value from onStartCommand() must be one of the following constants:

1. START_NOT_STICKY If the system kills the service after onStartCommand() returns, do not recreate the service unless there are pending intents to deliver. This is the safest option to avoid running your service when not necessary and when your application can simply restart any unfinished jobs.

2. START_STICKY If the system kills the service after onStartCommand() returns, recreate the service and call onStartCommand(), but do not redeliver the last intent. Instead, the system calls onStartCommand() with a null intent unless there are pending intents to start the service. In that case, those intents are delivered. This is suitable for media players (or similar services) that are not executing commands but are running indefinitely and waiting for a job.

3. START_REDELIVER_INTENT If the system kills the service after onStartCommand() returns, recreate the service and call onStartCommand() with the last intent that was delivered to the service. Any pending intents are delivered in turn. This is suitable for services that are actively performing a job that should be immediately resumed, such as downloading a file.

Note: In your case you should use Started Service and return START_STICKY or START_REDELIVER_INTENT (based on your requirement) in onStartCommand()

Check Official Documentation for detailed description of the Services.

Answer 2

您是否在清单文件中添加了这些行

<application> <service  android:name=".ExampleService" /></application>