需要获取触发的地理围栏中心的纬度和经度，但哈希地图返回空值

问题描述

我想检索创建的地理围栏的纬度和经度，在我考虑使用hashMap的GeoFencebroadcastReceiver.java类中（在这里我将使用地理围栏的ID作为键，然后返回得到地理围栏中心的LatLng作为值），但可惜hashMap为Empty，并且在logcat中检查时返回空值。在MapsActivity.java中的addGeoFence（）中使用geoFenceHelper.setHashmap（在GeoFenceHelper.java中创建的方法）{setHashMap在GeoFenceHelper.java类的底部}，然后在GeoFencebroadcastReceiver.java中使用getGeoFenceLatLng（String ID）来检索LatLng

再次总结一下，我认为使用hashMap在geofence ID和geofence LatLng之间创建键值对将对我有所帮助，但是hashMap返回的是null，我不希望返回null，但是值（ LatLng）。请解决此问题并在可能的情况下提供帮助。

在MapsActivity.java中

@Override
public void onMapLongClick(LatLng latLng) {
    float GEO_FENCE_RADIUS = 300;
    addGeoFence(latLng,GEO_FENCE_RADIUS);
}

private void addGeoFence(LatLng latLng,float geo_fence_radius) {
    String ID = UUID.randomUUID().toString();
    Log.d(TAG,"addGeoFence: String ID generated: " + ID);
    Log.d(TAG,"addGeoFence: LatLng latLng generated: " + latLng);

    Geofence geofence = geoFenceHelper.getGeoFence(ID,latLng,geo_fence_radius,Geofence.GEOFENCE_TRANSITION_ENTER |
            Geofence.GEOFENCE_TRANSITION_DWELL | Geofence.GEOFENCE_TRANSITION_EXIT);

    GeofencingRequest geofencingRequest = geoFenceHelper.getGeoFencingRequest(geofence);

    PendingIntent pendingIntent = geoFenceHelper.getPendingIntent();

    if (ActivityCompat.checkSelfPermission(this,Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) { return; }
    geofencingClient.addGeofences(geofencingRequest,pendingIntent)
            .addOnSuccessListener(new OnSuccessListener<Void>() {
                @Override
                public void onSuccess(Void aVoid) { Log.d(TAG,"onSuccess: GeoFence has been added"); }
            })
            .addOnFailureListener(new OnFailureListener() {
                @Override
                public void onFailure(@NonNull Exception exception) {
                    String error = geoFenceHelper.getErrorString(exception);
                    Log.d(TAG,"onFailure: GeoFence not added " + error); }
            });

    Log.d(TAG,"addGeoFence: String ID set To GeoFence: " + ID);
    Log.d(TAG,"addGeoFence: LatLng latLng set To GeoFence: " + latLng);

    geoFenceHelper.setHashMap(ID,latLng);    //This will call the setHashMap
}

在GeoFenceHelper.java

中

public class GeoFenceHelper extends Contextwrapper {

private static final String TAG = "GeoFenceHelper";

PendingIntent pendingIntent;
HashMap<String,LatLng> hashMap = new HashMap<>();

private static final int PENDING_INTENT_REQUEST_CODE = 234;

public GeoFenceHelper(Context base) { super(base); }

public Geofence getGeoFence(String ID,LatLng latLng,float radius,int TransitionTypes){
    return new Geofence.Builder()
            .setCircularRegion(latLng.latitude,latLng.longitude,radius)
            .setExpirationDuration(Geofence.NEVER_EXPIRE)
            .setLoiteringDelay(2000)
            .setRequestId(ID)
            .setTransitionTypes(TransitionTypes)
            .build();
}

public GeofencingRequest getGeoFencingRequest(Geofence geofence){
    return new GeofencingRequest.Builder()
            .addGeofence(geofence)
            .setinitialTrigger(GeofencingRequest.INITIAL_TRIGGER_ENTER)
            .build();
}

public PendingIntent getPendingIntent(){
    if (pendingIntent != null){ return pendingIntent; }
    Intent intent = new Intent(GeoFenceHelper.this,GeoFencebroadcastReceiver.class);
    pendingIntent = PendingIntent.getbroadcast(GeoFenceHelper.this,PENDING_INTENT_REQUEST_CODE,intent,PendingIntent.FLAG_UPDATE_CURRENT);
    return pendingIntent;
}

public String getErrorString(Exception e) {
    if (e instanceof ApiException) {
        ApiException apiException = (ApiException) e;
        switch (apiException.getStatusCode()) {
            case GeofenceStatusCodes.GEOFENCE_NOT_AVAILABLE:
                return "GEO_FENCE NOT AVAILABLE";
            case GeofenceStatusCodes.GEOFENCE_TOO_MANY_GEOFENCES:
                return "GEO_FENCE TOO MANY GEO_FENCES";
            case GeofenceStatusCodes.GEOFENCE_TOO_MANY_PENDING_INTENTS:
                return "GEO_FENCE TOO MANY PENDING INTENTS";
        }
    }
    return e.getLocalizedMessage();
}

public LatLng getGeoFenceLatLng(String ID) {
    Log.d(TAG,"getGeoFenceLatLng: the Id passed is: " + ID);

    if (this.hashMap.isEmpty()){
        Log.d(TAG,"getGeoFenceLatLng: HashMap is Empty");
        Toast.makeText(this,"HashMap is Empty",Toast.LENGTH_SHORT).show();
    }

    LatLng latLng = hashMap.get(ID);
    Log.d(TAG,"getHashMap: the LatLng in the hashMap is: " + latLng);
    return latLng;
}

public void setHashMap(String ID,LatLng latLng) {
    this.hashMap.put(ID,latLng);
    Log.d(TAG,"setHashMap: ID of the geoFence: " + ID);
    Log.d(TAG,"setHashMap: latLng of the geoFence: " + latLng);
} 

}

在GeoFencebroadcastReceiver.java中

public class GeoFencebroadcastReceiver extends broadcastReceiver {

private static final String TAG = "GeoFencebroadcastRec";
Location location;
LatLng latLng;

@Override
public void onReceive(Context context,Intent intent) {
    Log.d(TAG,"onReceive: geoFence added");

    GeofencingEvent geofencingEvent = GeofencingEvent.fromIntent(intent);

    GeoFenceHelper geoFenceHelper = new GeoFenceHelper(context);
    NotificationHelper notificationHelper = new NotificationHelper(context);

    if (geofencingEvent.hasError()) {
        Log.d(TAG,"onReceive: Error receiving geoFence event..." + geofencingEvent.getErrorCode());
        return;
    }

    List<Geofence> geoFenceList = geofencingEvent.getTriggeringGeofences();
    for (Geofence geofence: geoFenceList) {
        String ID = geofence.getRequestId();
        Log.d(TAG,"onReceive: RequestId of the geoFence: " + ID);
        latLng = geoFenceHelper.getGeoFenceLatLng(ID);
        Log.d(TAG,"onReceive: LatLng in hashMap: " + latLng);
    }

    location = geofencingEvent.getTriggeringLocation();
    Log.d(TAG,"onReceive: user location where it got detected: " + location.getLatitude() + " " + location.getLongitude());

    int transitionType = geofencingEvent.getGeofenceTransition();

    switch (transitionType) {
        case Geofence.GEOFENCE_TRANSITION_ENTER:
            Log.d(TAG,"onReceive: " + "GEO_FENCE TRANSITION ENTER");
            Toast.makeText(context,"GEO_FENCE TRANSITION ENTER",Toast.LENGTH_SHORT).show();
            break;
        case Geofence.GEOFENCE_TRANSITION_DWELL:
            Log.d(TAG,"onReceive: " + "GEO_FENCE TRANSITION DWELL");
            Toast.makeText(context,"GEO_FENCE TRANSITION DWELL",Toast.LENGTH_SHORT).show();
            break;
        case Geofence.GEOFENCE_TRANSITION_EXIT:
            Log.d(TAG,"onReceive: " + "GEO_FENCE TRANSITION EXIT");
            Toast.makeText(context,"GEO_FENCE TRANSITION EXIT",Toast.LENGTH_SHORT).show();
            break;
    }
}

}

如果还有另一种方法可以获取触发的地理围栏的经度和纬度，请告诉我，否则请尝试解决此问题。

解决方法

暂无找到可以解决该程序问题的有效方法，小编努力寻找整理中！

如果你已经找到好的解决方法，欢迎将解决方案带上本链接一起发送给小编。

小编邮箱:dio#foxmail.com (将#修改为@）