如果没有选择设备,并且使用后退键退出应用程序,则该代码也可以正常工作

那么我在这里做错了什么？当我的应用程序退出时,我认为是资源不会被清除.

public class ChromecastRouteProviderService extends MediaRouteProviderService {
final String LOGTAG = "Chromecast";
private static final String CONTROL_CATEGORY = CastMediaControlIntent.categoryForCast(CastMediaControlIntent.DEFAULT_MEDIA_RECEIVER_APPLICATION_ID);
private static final MediaRouteSelector SELECTOR = new MediaRouteSelector.Builder().addControlCategory(CONTROL_CATEGORY)
        .addControlCategory(MediaControlIntent.CATEGORY_REMOTE_PLAYBACK).build();
private IntentFilter controlFilter;

public ChromecastRouteProviderService() {
    controlFilter = new IntentFilter();
}

public void onCreate() {
    super.onCreate();
    controlFilter.addCategory(IAppConstants.CATEGORY);
    controlFilter.addCategory(MediaControlIntent.CATEGORY_REMOTE_PLAYBACK);
}

@Override
public MediaRouteProvider onCreateMediaRouteProvider() {
    return new ChromecastRouteProvider(this);
}

class ChromecastRouteProvider extends MediaRouteProvider {
    MediaRouter.Callback callback;
    Hashtable routes;

    public ChromecastRouteProvider(Context context) {
        super(context);
        routes = new Hashtable();
        callback = new CastCallBack();
    }

    @Nullable
    @Override
    public RouteController onCreateRouteController(String routeId) {
        MediaRouter.RouteInfo routeInfo = (MediaRouter.RouteInfo) routes.get(routeId);
        if (routeInfo == null) {
            return super.onCreateRouteController(routeId);
        } else {
            return new ChromecastRouteController(getContext(),routeInfo);
        }
    }

    @Override
    public void onDiscoveryRequestChanged(@Nullable MediaRouteDiscoveryRequest request) {
        super.onDiscoveryRequestChanged(request);
        if (request == null || !request.isActiveScan() || !request.isValid()) {
            stopScan();
            return;
        }
        if (!request.getSelector().hasControlCategory(IAppConstants.CATEGORY)) {
            Log.i(LOGTAG,"Not scanning for non remote playback");
            stopScan();
            return;
        } else {
            Log.i(LOGTAG,"Scanning...");
            mediarouter.addCallback(ChromecastRouteProviderService.SELECTOR,callback,MediaRouter.CALLBACK_FLAG_REQUEST_DISCOVERY);
            return;
        }
    }

    void updateDescriptor() {
        final MediaRouteProviderDescriptor.Builder descriptor = new MediaRouteProviderDescriptor.Builder();
        for (Iterator iterator = routes.values().iterator(); iterator.hasNext(); ) {
            MediaRouter.RouteInfo routeinfo = (MediaRouter.RouteInfo) iterator.next();
            try {
                Bundle bundle = new Bundle();
                bundle.putBoolean("has_upsell",true);
                descriptor.addRoute(new MediaRouteDescriptor.Builder(routeinfo.getId(),routeinfo.getName())
                        .addControlFilter(controlFilter).setPlaybackStream(3)
                        .setDescription(routeinfo.getDescription())
                        .setEnabled(true).setPlaybackType(MediaRouter.RouteInfo.PLAYBACK_TYPE_REMOTE)
                        .setVolumeHandling(1).setVolumeMax(100).setVolume(100)
                        .setExtras(bundle).build());
            } catch (Exception e) {
                throw new Error("wtf");
            }
        }

        getHandler().post(new Runnable() {
            @Override
            public void run() {
                setDescriptor(descriptor.build());
            }
        });

    }

    void stopScan() {
        Log.i(LOGTAG,"Stopping scan...");
        try {
            MediaRouter.getInstance(getContext()).removeCallback(callback);
            return;
        } catch (Exception exception) {
            return;
        }
    }

    class CastCallBack extends MediaRouter.Callback {
        void check(MediaRouter mediarouter,MediaRouter.RouteInfo routeinfo) {
            Log.i(LOGTAG,new StringBuilder().append("Checking route ").append
                    (routeinfo.getName()).toString());
            CastDevice device = CastDevice.getFromBundle(routeinfo.getExtras());
            if (routeinfo.matchesSelector(ChromecastRouteProviderService.SELECTOR)
                    && device != null && device.isOnLocalNetwork()) {
                routes.put(routeinfo.getId(),routeinfo);
                updateDescriptor();
                return;
            } else {
                return;
            }
        }

        public void onRouteAdded(MediaRouter mediarouter,MediaRouter.RouteInfo routeinfo) {
            super.onRouteAdded(mediarouter,routeinfo);
            check(mediarouter,routeinfo);
        }

        public void onRouteChanged(MediaRouter mediarouter,MediaRouter.RouteInfo routeinfo) {
            super.onRouteChanged(mediarouter,routeinfo);
        }

        public void onRouteRemoved(MediaRouter mediarouter,MediaRouter.RouteInfo routeinfo) {
            super.onRouteRemoved(mediarouter,routeinfo);
            if (routeinfo.matchesSelector(ChromecastRouteProviderService.SELECTOR)) ;
        }

    }
}

}