使用firebase数据库将标记添加到mapsactivity

Question

我正在尝试从firebase中检索数据，不幸的是显示标记，它只显示没有标记的地图和崩溃（强制关闭）。你能告诉我解决这个问题的解决方案吗？

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

Answer 1

我已经运行了你的代码，并且我的工作正常。如果崩溃问题在您的最后仍然存在，请在app gradle中使用以下版本尝试一次。

dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
    exclude group: 'com.android.support', module: 'support-annotations'
})
compile 'com.android.support:appcompat-v7:25.3.1'
compile 'com.google.android.gms:play-services-maps:9.2.0'

compile 'com.google.firebase:firebase-core:9.2.0'
compile 'com.google.firebase:firebase-database:9.2.0'
compile 'com.firebase:firebase-client-android:2.3.1'
compile 'com.google.firebase:firebase-messaging:9.2.0'
testCompile 'junit:junit:4.12'
}
apply plugin: 'com.google.gms.google-services'