java - Android 位置和线程

Question

我正在尝试大量使用位置 API。我做一个简单的 Activity 来使用 LocationListener 刷新 TextView 没有任何问题，这很好。

问题是，我必须将所有位置内容放入类似 Manager 类之类的东西中，该类由主 Activity 调用。所以我必须将所有内容放在该类中并将位置传递给 Activity 。这是 Activity :

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);        
    setContentView(R.layout.main);
    g = new GPSManager(getApplicationContext());
    t = new Thread(g);
    t.start();
    updateWithNewLocation(g.getLocation());
}    
private void updateWithNewLocation(Location location) {
    String latLongString;
    TextView myLocationText;
    myLocationText = (TextView)findViewById(R.id.loca);
    if (location != null) {
       double lat = location.getLatitude();
       double lng = location.getLongitude();
       latLongString = "Lat:" + lat + "\nLong:" + lng;
    } else {
       latLongString = "No location found";
    }
    myLocationText.setText("Your Current Position is:\n" +
    latLongString);
 }    

这是“Manager”类:

public GPSManager(Context context) {
    locationManager = (LocationManager)context.getSystemService(service); 
    String service = Context.LOCATION_SERVICE;
    Criteria criteria = new Criteria();
    criteria.setAccuracy(Criteria.ACCURACY_FINE);
    criteria.setAltitudeRequired(false);
    criteria.setBearingRequired(false);
    criteria.setCostAllowed(true);
    criteria.setPowerRequirement(Criteria.POWER_LOW);
    provider = locationManager.getBestProvider(criteria, true); 
}
public Location getLocation() {
    return this.location;
}
private final LocationListener locationListener = new LocationListener() {
    public void onLocationChanged(Location location) {
        Manager.this.location=location;
    }
    public void onProviderDisabled(String provider){
        locationManager.removeUpdates(this);
    }
    public void onProviderEnabled(String provider){ }
    public void onStatusChanged(String provider, int status,
        Bundle extras){ }
    };

@Override
public void run() {
   Looper.prepare();
   locationManager.requestLocationUpdates(provider, 0, 0,
           locationListener);        
   location = locationManager.getLastKnownLocation(provider);
   Looper.loop();
   Looper.myLooper().quit();
}
private Handler handler = new Handler() {
@Override
public void handleMessage(Message msg) {
    locationManager.removeUpdates(locationListener);
}

我遇到的问题是，它根本不起作用!如果我将此代码放入 Activity 中，不涉及任何线程，效果会很好。但这样，它只是说“找不到位置”。我需要让 Manager 类始终监听更改，因此当我请求当前位置时会更新。

Answer 1

选项#1:删除“manager”类。

选项#2:使“manager”类成为一个Service。

选项#3:使“manager”类成为自定义Application。

选项 #4:用 HandlerThread 替换 Thread。