基本上我有一个 android 服务 LogService，它是我从 MainActivity 触发的。在服务类中，我正在创建一个名为 locationFetcher 的 LocationListener 类 LocationFetcher 的对象。 LocationFetcher 类有一个公共(public)字符串成员 FormattedResult。现在在 LogService.run() 内部，我想定期获取 FormattedResult。怎么做 ？？以下是引用代码。
我有一个像这样的 LocationListener:
/*This is relevant content of LocationFetcher.java */
public class LocationFetcher extends TimerTask implements LocationListener{
public String FormattedResult;
private boolean availableFlag;
@Override
public void onLocationChanged(Location arg0) {
// TODO Auto-generated method stub
this.availableFlag=true;
this.FormattedResult=String.format(Locale.ENGLISH, "Lat=\t%f\nLong=\t%f", arg0.getLatitude(),arg0.getLongitude());
Log.d("LocationFetcher",this.FormattedResult);
}
@Override
public void run() {
// TODO Auto-generated method stub
Log.d("LocationFetcher","This is Timer Run !!!");
}}
我的安卓服务是这样的:
/* This is the relevant pert from LogService.java file*/
public class LogService extends Service{
private Logger logger;
private LocationFetcher locationFetcher;
public LocationManager locationManager;
private Timer timer1;
@Override
public int onStartCommand(Intent intent,int flags, int startId){
super.onStartCommand(intent, flags, startId);
if(!this.running){
this.logger = new Logger(); //Initiated member from subclass
this.logger.start(); //Started
this.timer1 = new Timer(); //Timer for timed job
this.locationFetcher = new LocationFetcher();//THIS IS MY EXTERNAL CLASS in "LocationFetcher.java"
//I am using GPS data.
this.locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
if(this.locationFetcher != null){//NULLPointerException is thrown if I REMOVE this if ??WHY
this.locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this.locationFetcher);
this.timer1.scheduleAtFixedRate(this.locationFetcher, 5000, 2000);
//Below Line still throws NullPointrException ??WHY
//this.locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, this.locationFetcher);
}else{
Log.d("GPS-Logger"," Found Null LocationFlecther !");
}
}
public void run(){
LogService ll = LogService.this;
LocationManager mgr = ll.locationManager; //THIS IS MY QUESTION
// HOW DO I ACCESS THE GPS LOCATION STORED in locationmanager.FormattedResult
// Which is a string
// //////////////////////////////////////////////////////////////////////////
while(ll.isActive){
try {
String temp ;
if(!temp.isEmpty()){
Log.d("GPS-Logger","data is :"+temp);
}
Log.d("GPS-Logger","data is :");
Thread.sleep(5000);
sec +=1 ;
if(sec >= 12){
Log.d("GPS-Logger","Sending Data Here");
sec = 0;
}
} catch (InterruptedException e) {
// TODO Auto-generated catch block
ll.isActive=false;
Log.d("GPS-Logged","EXIT Request Received");
}
}
}
我知道我在上面问了多个问题，但我不知道如何将它们分开。 需要帮助!!!
最佳答案
您可以将位置 Fetcher 修改为如下所示的“LocationListenerClass”:
修改后的类主要关注如下:
1.我使用了一个单例类来注册和删除整个区域的位置更新。(比如我们的服务等)。
2.您应该从 onLocationChngaed() 和 getCurrentLocation() 初始化位置字符串(在您的情况下为 FormattedResult)。因为 onLocationChngaed() 只会在距离和时间发生变化时调用，如 requestLocationUpdates 中提供的那样对此进行更多研究。
public class LocationListenerClass implements LocationListener{
private static LocationListenerClass instance;
private static Context context;
private LocationManager myLocationManager;
private LocationListener myLocationListener;
private Double latitude = 0d;
private Double longitude = 0d;
public static String FormattedResult;
public static LocationListenerClass getInstance(Context context) {
LocationListenerClass.context = context;
if (null == instance) {
instance = new LocationListenerClass();
}
return instance;
}
public void getCurrentLocation() {
try {
myLocationManager = (LocationManager) context
.getSystemService(Context.LOCATION_SERVICE);
myLocationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER, 30000, 100,
this);
Location location;
location = myLocationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location == null) {
myLocationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER, 30000, 100,
myLocationListener);
location = myLocationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
}
if (location != null) {
try {
latitude = location.getLatitude();
Data.CURENT_LATITUDE = latitude;
Log.v(ConstantLib.LOG, " latitude : "
+ Data.CURENT_LATITUDE);
longitude = location.getLongitude();
Data.CURENT_LONGITUDE = longitude;
Log.v(ConstantLib.LOG, " longitude : "
+ Data.CURENT_LONGITUDE);
**FormattedResult=String.format(Locale.ENGLISH, "Lat=\t%f\nLong=\t%f", latitude(),longitude());
Log.d("LocationFetcher",this.FormattedResult);**
} catch (Exception e) {
e.printStackTrace();
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
public void removeLocationUpdates() {
try {
if (myLocationManager != null) {
myLocationManager.removeUpdates(myLocationListener);
}
} catch (Exception e) {
}
}
public void onLocationChanged(Location location) {
try {
if (location != null) {
Data.CURENT_LATITUDE = location.getLatitude();
Log.v(ConstantLib.LOG, "LOCATION CHANGED" + " latitude : "
+ Data.CURENT_LATITUDE);
longitude = location.getLongitude();
Data.CURENT_LONGITUDE = location.getLongitude();
Log.v(ConstantLib.LOG, "LOCATION CHANGED" + " longitude : "
+ Data.CURENT_LONGITUDE);
**FormattedResult=String.format(Locale.ENGLISH, "Lat=\t%f\nLong=\t%f", latitude(),longitude());
Log.d("LocationFetcher",this.FormattedResult);**
}
} catch (Exception e) {
e.printStackTrace();
}
}
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
}
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
}
关于java - 如何访问android服务中的外部类成员？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/16140508/