假设我有一些数据如下：
{
"rallye" : {
"positions" : {
"ATYFOP8lNRThzrEC83" : {
".priority" : "u1q04dmvuq",
"g" : "u1q04dmvuq",
"l" : [ -116.04463242, 19.55545101 ]
},
"AZYF2P8lNSThzrEC63" : {
".priority" : "u1q04dtcbk",
"g" : "u1q04dtcbk",
"l" : [ 116.045306, 17.555276 ]
}
在我的firebase实时数据库中，
和这个Android类：
package com.sherdle.universal.rallye;
import android.support.v4.app.FragmentActivity;
import android.support.v7.app.AlertDialog;
import android.os.*;
import android.view.animation.AccelerateDecelerateInterpolator;
import android.view.animation.Interpolator;
import com.firebase.geofire.GeoFire;
import com.firebase.geofire.GeoLocation;
import com.firebase.geofire.GeoQuery;
import com.firebase.geofire.GeoQueryEventListener;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.mapbox.mapboxsdk.Mapbox;
import com.mapbox.mapboxsdk.annotations.Marker;
import com.mapbox.mapboxsdk.annotations.MarkerOptions;
import com.mapbox.mapboxsdk.camera.CameraPosition;
import com.mapbox.mapboxsdk.camera.CameraUpdateFactory;
import com.mapbox.mapboxsdk.geometry.LatLng;
import com.mapbox.mapboxsdk.maps.MapboxMap;
import com.mapbox.mapboxsdk.maps.OnMapReadyCallback;
import com.mapbox.mapboxsdk.maps.SupportMapFragment;
import com.sherdle.universal.R;
import java.util.HashMap;
import java.util.Map;
public class rallye_activity extends FragmentActivity implements GeoQueryEventListener, MapboxMap.OnCameraChangeListener {
// in welchem Suchradius sollen andere Teams auf der Karte angezeigt werden?
private static final int TEAMSIMRADIUS = 100;
private static final GeoLocation INITIAL_CENTER = new GeoLocation(52.543535, 8.55123);
private static final int INITIAL_ZOOM_LEVEL = 14;
private static final String GEO_FIRE_REF = "/rallye/positions";
private MapboxMap map;
private GeoFire geoFire;
private GeoQuery geoQuery;
private Map<String,Marker> markers;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.content_rallye_activity);
Mapbox.getInstance(this, getString(R.string.mapbox_access_token));
SupportMapFragment mapFragment = (SupportMapFragment)getSupportFragmentManager().findFragmentById(R.id.container);
this.map = mapFragment.getMap();
LatLng latLngCenter = new LatLng(INITIAL_CENTER.latitude, INITIAL_CENTER.longitude);
this.map.moveCamera(CameraUpdateFactory.newLatLngZoom(latLngCenter, INITIAL_ZOOM_LEVEL));
this.map.setOnCameraChangeListener(this);
DatabaseReference ref = FirebaseDatabase.getInstance().getReference("/rallye/positions");
final GeoFire geoFire = new GeoFire(ref);
// radius in km
this.geoQuery = this.geoFire.queryAtLocation(INITIAL_CENTER, 1);
// setup markers
this.markers = new HashMap<String, Marker>();
}
@Override
protected void onStart() {
super.onStart();
// add an event listener to start updating locations again
this.geoQuery.addGeoQueryEventListener(this);
}
@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
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(DatabaseError 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.getLatitude()) * v + startPosition.getLatitude();
double currentLng = (lng - startPosition.getLongitude()) * v + startPosition.getLongitude();
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.geoQuery.setCenter(new GeoLocation(center.getLatitude(), center.getLongitude()));
// radius in km
this.geoQuery.setRadius(radius/1000);
}
}
这是我的布局XML
<?xml version="1.0" encoding="utf-8"?>
<fragment xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/map"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:name="com.mapbox.mapboxsdk.maps.SupportMapFragment"/>
事实上：我想在此Mapbox地图上实时显示我的地理位置数据和多个标记。
但是我得到了这个错误
this.map = mapFragment.getMap();
然后我使用“new”函数：getMapAsync（）
this.map = mapFragment.getMapAsync(this);
如果没有这些功能，我会收到此错误：
FATAL EXCEPTION: main
Process: com.foo.bar, PID: 12380
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.foo.bar/com.sherdle.universal.rallye.rallye_activity}: android.view.InflateException: Binary XML file line #2: Error inflating class fragment
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2689)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2754)
at android.app.ActivityThread.access$900(ActivityThread.java:177)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1448)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:145)
at android.app.ActivityThread.main(ActivityThread.java:5938)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1400)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1195)
Caused by: android.view.InflateException: Binary XML file line #2: Error inflating class fragment
at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:770)
at android.view.LayoutInflater.inflate(LayoutInflater.java:483)
at android.view.LayoutInflater.inflate(LayoutInflater.java:415)
at android.view.LayoutInflater.inflate(LayoutInflater.java:366)
at android.transition.Scene.enter(Scene.java:175)
at com.android.internal.policy.impl.PhoneWindow.transitionTo(PhoneWindow.java:483)
at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:426)
at android.app.Activity.setContentView(Activity.java:2267)
at com.sherdle.universal.rallye.rallye_activity.onCreate(rallye_activity.java:54)
答案 0 :(得分：0)
您使用错误的ID来查找片段。 XML中定义的ID为map。您正在搜索container。
变化：
SupportMapFragment mapFragment = (SupportMapFragment)getSupportFragmentManager()
.findFragmentById(R.id.container);
为：
SupportMapFragment mapFragment = (SupportMapFragment)getSupportFragmentManager()
.findFragmentById(R.id.map);