我创建了一个 Android 应用程序，该应用程序的用户登录和注册链接到我的 Firebase 数据库。
我正在尝试使用 Geofire 来存储和显示在地图上登录的用户，我使用了 SF 车辆示例，老实说，我不太了解它。我已经使用完全相同的代码进行测试，看看它是否有效，并且我在提供的图像中得到了错误。
我正在寻求帮助编写一个函数来检测登录用户的位置并将其实时显示在地图上，随着用户的移动而更新，我现在被困在这几周并且已经尝试了那里的所有内容（其中不是很多）。
一些帮助将不胜感激，任何进一步的信息需要询问。
这是我正在使用的 SF Vehicle 示例中的代码，原始代码连接到旧金山巴士部门并显示它们，所以我需要代码将位置写入我的数据库并以相同的方式显示它们。
package nixer.nixer;
import android.app.AlertDialog;
import android.app.Fragment;
import android.content.Intent;
import android.graphics.Color;
import android.os.Bundle;
import android.os.Handler;
import android.os.SystemClock;
import android.support.v4.app.FragmentActivity;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.view.animation.AccelerateDecelerateInterpolator;
import android.view.animation.Interpolator;
import com.firebase.client.Firebase;
import com.firebase.client.FirebaseError;
import com.firebase.geofire.GeoFire;
import com.firebase.geofire.GeoLocation;
import com.firebase.geofire.GeoQuery;
import com.firebase.geofire.GeoQueryEventListener;
import com.firebase.geofire.LocationCallback;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.*;
import java.util.HashMap;
import java.util.Map;
public class MapActivity extends AppCompatActivity implements GeoQueryEventListener, GoogleMap.OnCameraChangeListener {
private Firebase mRef;
private String mUserId;
private String itemsUrl;
private static final GeoLocation INITIAL_CENTER = new GeoLocation(53.349805, -6.260309 );
private static final int INITIAL_ZOOM_LEVEL = 14;
private static final String GEO_FIRE_REF = "https://nixer.firebaseio.com/";
private GoogleMap map;
private Circle searchCircle;
private GeoFire geoFire;
private GeoQuery geoQuery;
private Map<String,Marker> markers;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_map);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
// setup map and camera position
SupportMapFragment mapFragment = (SupportMapFragment)getSupportFragmentManager().findFragmentById(R.id.map);
this.map = mapFragment.getMap();
LatLng latLngCenter = new LatLng(INITIAL_CENTER.latitude, INITIAL_CENTER.longitude);
this.searchCircle = this.map.addCircle(new CircleOptions().center(latLngCenter).radius(1000));
this.searchCircle.setFillColor(Color.argb(66, 255, 0, 255));
this.searchCircle.setStrokeColor(Color.argb(66, 0, 0, 0));
this.map.moveCamera(CameraUpdateFactory.newLatLngZoom(latLngCenter, INITIAL_ZOOM_LEVEL));
this.map.setOnCameraChangeListener(this);
Firebase.setAndroidContext(this);
// setup GeoFire
this.geoFire = new GeoFire(new Firebase(GEO_FIRE_REF));
// radius in km
this.geoQuery = this.geoFire.queryAtLocation(INITIAL_CENTER, 1);
// setup markers
this.markers = new HashMap<String, Marker>();
// Check Authentication
mRef = new Firebase(Constants.FIREBASE_URL);
if (mRef.getAuth() == null) {
loadLoginView();
}
try {
mUserId = mRef.getAuth().getUid();
} catch (Exception e) {
loadLoginView();
}
}
@Override
protected void onStop() {
super.onStop();
// remove all event listeners to stop updating in the background
this.geoQuery.removeAllListeners();
for (Marker marker: this.markers.values()) {
marker.remove();
}
this.markers.clear();
}
@Override
protected void onStart() {
super.onStart();
// add an event listener to start updating locations again
this.geoQuery.addGeoQueryEventListener(this);
}
@Override
public void onKeyEntered(String key, GeoLocation location) {
// Add a new marker to the map
Marker marker = this.map.addMarker(new MarkerOptions().position(new LatLng(location.latitude, location.longitude)));
this.markers.put(key, marker);
}
@Override
public void onKeyExited(String key) {
// Remove any old marker
Marker marker = this.markers.get(key);
if (marker != null) {
marker.remove();
this.markers.remove(key);
}
}
@Override
public void onKeyMoved(String key, GeoLocation location) {
// Move the marker
Marker marker = this.markers.get(key);
if (marker != null) {
this.animateMarkerTo(marker, location.latitude, location.longitude);
}
}
@Override
public void onGeoQueryReady() {
}
@Override
public void onGeoQueryError(FirebaseError error) {
new AlertDialog.Builder(this)
.setTitle("Error")
.setMessage("There was an unexpected error querying GeoFire: " + error.getMessage())
.setPositiveButton(android.R.string.ok, null)
.setIcon(android.R.drawable.ic_dialog_alert)
.show();
}
// Animation handler for old APIs without animation support
private void animateMarkerTo(final Marker marker, final double lat, final double lng) {
final Handler handler = new Handler();
final long start = SystemClock.uptimeMillis();
final long DURATION_MS = 3000;
final Interpolator interpolator = new AccelerateDecelerateInterpolator();
final LatLng startPosition = marker.getPosition();
handler.post(new Runnable() {
@Override
public void run() {
float elapsed = SystemClock.uptimeMillis() - start;
float t = elapsed/DURATION_MS;
float v = interpolator.getInterpolation(t);
double currentLat = (lat - startPosition.latitude) * v + startPosition.latitude;
double currentLng = (lng - startPosition.longitude) * v + startPosition.longitude;
marker.setPosition(new LatLng(currentLat, currentLng));
// if animation is not finished yet, repeat
if (t < 1) {
handler.postDelayed(this, 16);
}
}
});
}
private double zoomLevelToRadius(double zoomLevel) {
// Approximation to fit circle into view
return 16384000/Math.pow(2, zoomLevel);
}
@Override
public void onCameraChange(CameraPosition cameraPosition) {
// Update the search criteria for this geoQuery and the circle on the map
LatLng center = cameraPosition.target;
double radius = zoomLevelToRadius(cameraPosition.zoom);
this.searchCircle.setCenter(center);
this.searchCircle.setRadius(radius);
this.geoQuery.setCenter(new GeoLocation(center.latitude, center.longitude));
// radius in km
this.geoQuery.setRadius(radius/1000);
}
更新：
Firebase 规则：
{
"rules": {
"users": {
"$uid": {
".read": "auth != null && auth.uid == $uid",
".write": "auth != null && auth.uid == $uid",
"items": {
"$item_id": {
"title": {
".validate": "newData.isString() && newData.val().length > 0"
}
}
}
}
}
}
}