Java 正在尝试获取用户';使用单例、服务和警报将s位置加载到地图上
到目前为止,我已经设置了一个闹钟,每隔一段时间就会醒来,然后记录用户的经度和纬度。这存储在singleton类Java 正在尝试获取用户';使用单例、服务和警报将s位置加载到地图上,java,android,service,singleton,alarmmanager,Java,Android,Service,Singleton,Alarmmanager,到目前为止,我已经设置了一个闹钟,每隔一段时间就会醒来,然后记录用户的经度和纬度。这存储在singleton类位置中,该位置将加载到不同的活动中,并根据上次记录的位置作为标记放置在地图上 目标 我希望应用程序即使在关闭时也能跟踪用户的位置,比如为什么我使用AlarmManager在一定时间后唤醒设备并获取坐标,直到他们请求停止 问题 即使该类返回先前记录的位置值,即坐标,调用该函数将位置放置在地图上的活动也会返回坐标(0.0,0.0),即null,假设它正在初始化对象,就好像它不存在一样 有什么
位置中,该位置将加载到不同的活动中,并根据上次记录的位置作为标记放置在地图上
目标
我希望应用程序即使在关闭时也能跟踪用户的位置,比如为什么我使用AlarmManager
在一定时间后唤醒设备并获取坐标,直到他们请求停止
问题
即使该类返回先前记录的位置
值,即坐标,调用该函数将位置放置在地图上的活动也会返回坐标(0.0,0.0),即null,假设它正在初始化对象,就好像它不存在一样
有什么问题吗
位置-单身人士
public class Position {
private double latitude;
private double longitude;
private String coordinate;
private String service;
private static Position instance;
private Position() {
}
public String getCoordinate() {
return coordinate;
}
public void setCoordinate(String coordinate) {
this.coordinate = coordinate;
}
public double getLongitude() {
return longitude;
}
public void setLongitude(double longitude) {
this.longitude = longitude;
}
public double getLatitude() {
return latitude;
}
public void setLatitude(double latitude) {
this.latitude = latitude;
}
public String getService() {
return service;
}
public void setService(String service) {
this.service = service;
}
public static Position getInstance() {
if (instance == null) {
instance = new Position();
}
return instance;
}
}
报警-跟踪位置的位置
public class Alarm extends BroadcastReceiver {
@Override
public void onReceive(final Context context, Intent intent) {
PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "");
wl.acquire();
// get the service code
String serviceCode = intent.getStringExtra("serviceCode");
// get the last known location
LocationManager locationManager = (LocationManager)context.getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
String provider = locationManager.getBestProvider(criteria, true);
Location location = locationManager.getLastKnownLocation(provider);
//store the latitude and longitude locally
double latitude = location.getLatitude();
double longitude = location.getLongitude();
String coordinate = latitude + ", " + longitude;
Position pos = Position.getInstance();
Log.d("", "Previous position: " + pos.getCoordinate());
pos.setLatitude(latitude);
pos.setLongitude(longitude);
pos.setCoordinate(coordinate);The
pos.setService(serviceCode);
Log.d("", "Found new position: " + pos.getCoordinate());
wl.release();
}
public void SetAlarm(Context context) {
AlarmManager am=(AlarmManager)context.getSystemService(Context.ALARM_SERVICE);
Intent i = new Intent(context, Alarm.class);
PendingIntent pi = PendingIntent.getBroadcast(context, 0, i, 0);
am.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(), 10000, pi); // Millisec * Second * Minute
}
public void CancelAlarm(Context context) {
Intent intent = new Intent(context, Alarm.class);
PendingIntent sender = PendingIntent.getBroadcast(context, 0, intent, 0);
AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
alarmManager.cancel(sender);
}
}
定位服务-是什么初始化了报警
public class LocationService extends android.app.Service {
Alarm alarm = new Alarm();
private NotificationManager nm;
@Override
public void onCreate() {
super.onCreate();
showNotification();
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
alarm.SetAlarm(LocationService.this);
return START_STICKY;
}
private void showNotification() {
// set up notification label to notify user that the app is still tracking the location
nm = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
CharSequence text = "Press to stop tracking";
// don't let user close it, for the purpose of always letting them know the location tracker is still running
Notification notification = new Notification(R.drawable.fav_buses, text, System.currentTimeMillis());
notification.flags = Notification.FLAG_NO_CLEAR;
// for older APIs
PendingIntent contentIntent = PendingIntent.getActivity(this, 0, new Intent(this, PushLocationActivity.class), 0);
notification.setLatestEventInfo(this, "Tracking Your Location", text, contentIntent);
nm.notify(R.string.notification_id, notification);
}
@Override
public void onDestroy() {
super.onDestroy();
alarm.CancelAlarm(LocationService.this);
nm.cancel(R.string.notification_id);
Log.d("", "DESTROYED");
}
@Override
public IBinder onBind(Intent intent) {
return null;
}
}
StopsFragment-发生NullPointerException的位置
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
stops = new HashMap<>();
stopList = StopList.getInstance(getActivity()).getStops();
request = getArguments().getString("request");
position = Position.getInstance();
Log.d("", position.getCoordinate());
}
@覆盖
创建时的公共void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
stops=newhashmap();
stopList=stopList.getInstance(getActivity()).getStops();
请求=getArguments().getString(“请求”);
position=position.getInstance();
Log.d(“,position.getCoordinate());
}
您不应该采用这种方法,这会耗尽设备电池的电量。Android有特定的API来接收用户的重要位置更改,您应该使用它们。请点击以下链接:
只需调整代码,而不是活动,代码应该从服务执行,并且应该调用服务在引导时执行。我以前使用过这个,但目标是让应用程序即使在关闭时也能获得位置更新,至于我为什么使用AlarmManager
。用户更改位置时,即使应用程序已关闭,也会使用该代码通知您的应用程序。查看此代码:只需将代码从活动更改为服务,并在引导时启动服务。