【发布时间】：2017-06-03 10:22:17
【问题描述】：
我正在尝试从 firebase 检索数据，不幸的是，它没有显示标记，而是显示没有标记的地图并崩溃（强制关闭）。你能告诉我解决这个问题的方法吗？
这是我的 MapsActivity.java
package com.example.rizkafs.laundrize;
import android.content.Context;
import android.content.pm.PackageManager;
import android.content.res.Resources;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationManager;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.ActivityCompat;
import android.support.v4.app.FragmentActivity;
import android.os.Bundle;
import android.util.Log;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.BitmapDescriptor;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.CameraPosition;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MapStyleOptions;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;
import java.util.ArrayList;
public class NearbyActivity extends FragmentActivity implements OnMapReadyCallback {
private static final String TAG = NearbyActivity.class.getSimpleName();
private GoogleMap mMap;
Double latitude;
Double longitude;
String namaTempat;
String alamat;
String jenis;
String harga;
String jamOperasi;
String noTelp;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_nearby);
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
}
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
try {
// Customise the styling of the base map using a JSON object defined
// in a raw resource file.
boolean success = googleMap.setMapStyle(
MapStyleOptions.loadRawResourceStyle(
this, R.raw.style_json));
if (!success) {
Log.e(TAG, "Style parsing failed.");
}
} catch (Resources.NotFoundException e) {
Log.e(TAG, "Can't find style. Error: ", e);
}
DatabaseReference myRef = FirebaseDatabase.getInstance().getReference();
myRef.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot child : dataSnapshot.child("places").getChildren()){
latitude = child.child("latitude").getValue(Double.class);
longitude = child.child("longitude").getValue(Double.class);
namaTempat = child.child("nama_tempat").getValue(String.class);
alamat = child.child("alamat").getValue(String.class);
jenis = child.child("jenis").getValue(String.class);
harga = child.child("harga").getValue(String.class);
jamOperasi = child.child("jam_operasional").getValue(String.class);
noTelp = child.child("no_telp").getValue(String.class);
LatLng latLng = new LatLng(latitude, longitude);
mMap.addMarker(new MarkerOptions()
.position(latLng)
.title(namaTempat)
.icon(BitmapDescriptorFactory.fromResource(R.drawable.laundry)));
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
LocationManager locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// ActivityCompat#requestPermissions
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for ActivityCompat#requestPermissions for more details.
return;
}
Location location = locationManager.getLastKnownLocation(locationManager.getBestProvider(criteria, false));
if(location != null) {
CameraPosition cameraPosition = new CameraPosition.Builder()
.target(new LatLng(location.getLatitude(), location.getLongitude()))
.zoom(17)
.build();
mMap.moveCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));
}
}
}
这是我在 Firebase 中的数据库
数据库结构
【问题讨论】：
标签： java android google-maps marker