我需要使用 LocationManager 接收位置，在我的 Realm 数据库中搜索，最后使用 adapter.notifyDataSetChanged() 更新 RealmRecyclerViewAdapter。所以我做了这个 Observable:
private void getLocation() {
int GPSoff = -1;
try {
GPSoff = Settings.Secure.getInt(getActivity().getContentResolver(), Settings.Secure.LOCATION_MODE);
} catch(Settings.SettingNotFoundException e) {
e.printStackTrace();
}
if(GPSoff == 0) {
new AlertDialog.Builder(getActivity()).setTitle("Couldn't get your current location")
.setMessage("Do you want to enable location?")
.setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
Intent onGPS = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
startActivity(onGPS);
}
})
.setNegativeButton(android.R.string.no, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
// do nothing
}
})
.show();
}
Observable.create(new Observable.OnSubscribe<Location>() {
LocationManager mLocationManager;
public void call(final Subscriber<? super Location> subscriber) {
final LocationListener listener = new LocationListener() {
@Override
public void onLocationChanged(Location location) {
if(location != null) {
Log.v("Location Changed", location.getLatitude() + " and " + location.getLongitude());
subscriber.onNext(location);
try {
mLocationManager.removeUpdates(this);
subscriber.onCompleted();
} catch(SecurityException e) {
e.printStackTrace();
}
}
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
};
mLocationManager = (LocationManager) getActivity().getSystemService(Context.LOCATION_SERVICE);
try {
Location location = mLocationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if(location != null && location.getTime() > Calendar.getInstance().getTimeInMillis() - 2 * 60 * 1000) {
subscriber.onNext(location);
subscriber.onCompleted();
} else {
getActivity().runOnUiThread(new Runnable() {
@Override
public void run() {
try {
// .requestLocationUpdates(LocationManager.GPS_PROVIDER,
// GPS_TIME_INTERVAL, GPS_DISTANCE, GPSListener);
mLocationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 10000, listener);
mLocationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 10000, listener);
} catch(SecurityException e) {
e.printStackTrace();
}
}
});
}
} catch(SecurityException e) {
e.printStackTrace();
}
}
}).subscribeOn(Schedulers.newThread()).subscribe(new Subscriber<Location>() {
@Override
public void onCompleted() {
logThreadSignature();
getActivity().runOnUiThread(new Runnable() {
@Override
public void run() {
nearbs = realm.where(Airport.class)
.greaterThanOrEqualTo("latitudeDeg", (latitude - 0.5))
.lessThanOrEqualTo("latitudeDeg", (latitude + 0.5))
.greaterThanOrEqualTo("longitudeDeg", longitude - 0.5)
.lessThanOrEqualTo("longitudeDeg", longitude + 0.5)
.findAllAsync();
logThreadSignature();
adapter.notifyDataSetChanged();
}
});
}
@Override
public void onError(Throwable e) {
e.printStackTrace();
}
@Override
public void onNext(Location location) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
});
}
问题是我没有看到我的适配器有任何变化。这是适配器的代码:
public class AirportsAdapter
extends RealmRecyclerViewAdapter<Airport, RecyclerView.ViewHolder>
implements Filterable {
Context context;
String countryName;
public static final int FILTER_MODE_A = 0;
public static final int FILTER_MODE_B = 1;
OrderedRealmCollection<Airport> listAirports;
RealmResults<Airport> nearby;
Realm realm;
int NEARBY = 0;
int AIRPORTS = 2;
int nearbySize;
int COUNTRY = 3;
boolean countryFlag = false;
int ALL = 1;
public AirportsAdapter(Context context, OrderedRealmCollection<Airport> airports, RealmResults<Airport> nearby, Realm realm) {
super(context, airports, true);
this.context = context;
this.listAirports = airports;
this.realm = realm;
this.nearby = nearby;
Log.d("nearv", String.valueOf(nearby.size()));
}
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
if(viewType == NEARBY) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.input_custom_item, parent, false);
MenuHolder menuHolder = new MenuHolder(view);
return menuHolder;
} else if(viewType == ALL) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.input_custom_item, parent, false);
MenuHolder menuHolder = new MenuHolder(view);
return menuHolder;
}
if(viewType == COUNTRY) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.input_custom_item, parent, false);
MenuHolder menuHolder = new MenuHolder(view);
return menuHolder;
} else {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.airport_show, parent, false);
AirportClass holder = new AirportClass(view);
return holder;
}
}
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
if(getItemViewType(position) == NEARBY) {
Log.i("ivt", String.valueOf(position));
MenuHolder mHolder = (MenuHolder) holder;
mHolder.type.setText("Nearby");
mHolder.type.setTypeface(Typeface.createFromAsset(context.getAssets(), "fonts/Avenir-Medium.ttf"), Typeface.BOLD);
} else if(getItemViewType(position) == ALL) {
MenuHolder mHolder = (MenuHolder) holder;
mHolder.type.setText("All");
mHolder.type.setTypeface(Typeface.createFromAsset(context.getAssets(), "fonts/Avenir-Medium.ttf"), Typeface.BOLD);
} else if(getItemViewType(position) == COUNTRY) {
MenuHolder mHolder = (MenuHolder) holder;
mHolder.type.setText(countryName);
mHolder.type.setTypeface(Typeface.createFromAsset(context.getAssets(), "fonts/Avenir-Medium.ttf"), Typeface.BOLD);
} else if(getItemViewType(position) == AIRPORTS) {
AirportClass mHolder = (AirportClass) holder;
Airport airport = listAirports.get(position - 1);
String country = airport.getIsoCountry().toLowerCase();
if(country.equals("do")) {
country = "dom";
}
int imgID = context.getResources().getIdentifier(country, "drawable", context.getPackageName());
Glide.with(context).load(imgID).into(mHolder.image);
mHolder.des.setText(airport.getIdent());
mHolder.name.setText(airport.getName());
mHolder.des.setTypeface(Typeface.createFromAsset(context.getAssets(), "fonts/Avenir-Book.ttf"), Typeface.BOLD);
mHolder.name.setTypeface(Typeface.createFromAsset(context.getAssets(), "fonts/Avenir-Book.ttf"));
}
}
public int getItemViewType(int position) {
if((position == 0) && (nearbySize != 0) && (!countryFlag)) {
return NEARBY;
} else if((position == 0) && (nearbySize == 0) && (!countryFlag)) {
return ALL;
} else if((position == 0) && (countryFlag)) {
return COUNTRY;
} else {
return AIRPORTS;
}
}
@Override
public int getItemCount() {
if((nearbySize == 0) && (!countryFlag)) {
//rivedere
return 1 + listAirports.size();
} else if((!countryFlag) && (nearbySize != 0)) {
return 1 + listAirports.size();
} else {
return 1 + listAirports.size();
}
}
public void filterResults(String text, int filterMode) {
String txt = text;
text = text == null ? null : text.toLowerCase().trim();
if(text == null || "".equals(text)) {
listAirports = realm.where(Airport.class).findAll();
} else {
if(filterMode == FILTER_MODE_A) {
listAirports = realm.where(Airport.class).contains("name", text, Case.INSENSITIVE).findAll();
countryFlag = false;
}
if(filterMode == FILTER_MODE_B) {
System.out.print(text);
countryFlag = true;
Countries country = realm.where(Countries.class).equalTo("name", txt).findFirst();
countryName = country.getName();
listAirports = realm.where(Airport.class).equalTo("isoCountry", country.getCode(), Case.INSENSITIVE).findAll();
}
}
updateData(listAirports);
}
public Filter getFilter(int filterMode) {
AirportFilter filter = new AirportFilter(this, filterMode);
return filter;
}
@Override
public Filter getFilter() {
return null;
}
private class AirportFilter
extends Filter {
private final AirportsAdapter adapter;
private int filterMode;
private AirportFilter(AirportsAdapter adapter, int filterMode) {
super();
this.adapter = adapter;
this.filterMode = filterMode;
}
@Override
protected FilterResults performFiltering(CharSequence constraint) {
if(filterMode == FILTER_MODE_A) {
return new Filter.FilterResults();
}
if(filterMode == FILTER_MODE_B) {
return new Filter.FilterResults();
}
return new Filter.FilterResults();
}
@Override
protected void publishResults(CharSequence constraint, FilterResults results) {
adapter.filterResults(constraint.toString(), filterMode);
}
}
private class AirportClass
extends RecyclerView.ViewHolder {
TextView name, des;
ImageView image;
public AirportClass(View itemView) {
super(itemView);
name = (TextView) itemView.findViewById(R.id.name);
des = (TextView) itemView.findViewById(R.id.item);
image = (ImageView) itemView.findViewById(R.id.color);
}
}
private class MenuHolder
extends RecyclerView.ViewHolder {
TextView type;
public MenuHolder(View itemView) {
super(itemView);
type = (TextView) itemView.findViewById(R.id.init);
}
}
}
我该如何解决这个问题？
谢谢
最佳答案
您可以注册一个回调以在您的 RealmQuery 完成时运行，在此回调中您可以根据需要更新您的适配器。
您正在使用异步版本，这意味着它不会立即返回。
nearbs = realm.where(Airport.class)
.greaterThanOrEqualTo("latitudeDeg", (latitude - 0.5))
.lessThanOrEqualTo("latitudeDeg", (latitude + 0.5))
.greaterThanOrEqualTo("longitudeDeg", longitude - 0.5)
.lessThanOrEqualTo("longitudeDeg", longitude + 0.5)
.findAllAsync();
nearbs.addChangeListener(callback);
private RealmChangeListener callback = new RealmChangeListener() {
@Override
public void onChange(RealmResults<Airport> results) {
adapter.notifyDataSetChanged();
}
};
有关 Realm 查询和回调的更多信息，请参阅此链接。 https://realm.io/docs/java/latest/#queries
关于android - Realm 查询不更新我的适配器，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/41692136/