等到GPS位置retrived为ListActivity [英] Wait until GPS location is retrived for ListActivity
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问题描述
我的工作中，我使用GPS数据显示附近餐馆的Android项目。在服务器端，我已经实现了haversine公式得到取决于经度和纬度检索到附近的餐馆。但是，我有一个问题，因为我应该怎么告诉我的ListActivity类等到非零GPS位置检索。
I am working on an Android project in which I am using GPS data for showing nearby Restaurants. On the server side, I have implemented the Haversine formula to get nearby Restaurants depending upon the longitude and latitude retrieved. But, I am having a problem as to how should I tell my ListActivity class to wait until a non-zero GPS location is retrieved.
我查过类似的问题，但他们没有提供ListActivity任何帮助。任何帮助将是很好。非常感谢。
I checked similar questions, but they didn't provide any help for ListActivity. Any help would be nice. Thanks a lot.
ListRestaurants code：
ListRestaurants code :
public class RestaurantList extends ListActivity {
private ResponseEntity<RestRestaurant[]> responseEntity;
private OrderAdapter m_adapter;
private ArrayList<RestRestaurant> m_orders = null;
GPSTracker gps;
double longitude, latitude;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.restos);
final RestTemplate restTemplate = StaticRestTemplate.getRest();
final String restaurantList = StaticRestTemplate.baseURL+"getnearbyrestaurants";
gps = new GPSTracker(RestaurantList.this);
long TIMEOUT = 5000l; // 5 seconds
long startTime = new Date().getTime();
while (!gps.canGetLocation()) {
gps.showSettingsAlert();
long difference = new Date().getTime() - startTime;
if (TIMEOUT > difference) break;
}
latitude = gps.getLatitude();
longitude = gps.getLongitude();
Toast.makeText(getApplicationContext(), "Your Location is - \nLat: " + latitude + "\nLong: " + longitude, Toast.LENGTH_LONG).show();
/* if (gps.canGetLocation()) {
latitude = gps.getLatitude();
longitude = gps.getLongitude();
Toast.makeText(getApplicationContext(), "Your Location is - \nLat: " + latitude + "\nLong: " + longitude, Toast.LENGTH_LONG).show();
} else {
gps.showSettingsAlert();
}*/
Thread thread = new Thread(new Runnable() {
@Override
public void run() {
HttpHeaders requestHeaders = new HttpHeaders();
requestHeaders.add("Cookie", "JSESSIONID=" + StaticRestTemplate.jsessionid);
requestHeaders.setAccept(Collections.singletonList(new MediaType("application", "json")));
HttpEntity<?> requestEntity = new HttpEntity<Object>(requestHeaders);
restTemplate.getMessageConverters().add(new MappingJackson2HttpMessageConverter());
responseEntity = restTemplate.exchange(restaurantList+"/"+longitude+"/"+latitude,
HttpMethod.GET, requestEntity, RestRestaurant[].class);
}
});
thread.start();
ProgressDialog progress = new ProgressDialog(this);
progress.setTitle("Loading");
progress.setMessage("Wait while loading...");
try {
thread.join();
} catch (InterruptedException e) {
e.printStackTrace();
}
progress.dismiss();
RestRestaurant[] restRestaurantList = responseEntity.getBody();
m_orders = new ArrayList<RestRestaurant>();
this.m_adapter = new OrderAdapter(this, android.R.layout.simple_list_item_1, m_orders);
for (RestRestaurant restRestaurant1 : restRestaurantList) {
m_adapter.add(restRestaurant1);
}
setListAdapter(this.m_adapter);
现在，你可以在线程看到的，我传递的经度和纬度。我并不想通过非零数据存在。
Now, as you can see in the thread, I am passing the longitude and latitude. I don't want to pass non-zero data there.
下面是GPSTracker code我使用的：
Here is the GPSTracker code I am using :
public class GPSTracker extends Service implements LocationListener {
private final Context mContext;
// flag for GPS status
boolean isGPSEnabled = false;
// flag for network status
boolean isNetworkEnabled = false;
// flag for GPS status
boolean canGetLocation = false;
Location location; // location
double latitude; // latitude
double longitude; // longitude
// The minimum distance to change Updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10; // 10 meters
// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1; // 1 minute
// Declaring a Location Manager
protected LocationManager locationManager;
public GPSTracker(Context context) {
this.mContext = context;
getLocation();
}
public Location getLocation() {
try {
locationManager = (LocationManager) mContext
.getSystemService(LOCATION_SERVICE);
// getting GPS status
isGPSEnabled = locationManager
.isProviderEnabled(LocationManager.GPS_PROVIDER);
// getting network status
isNetworkEnabled = locationManager
.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (!isGPSEnabled && !isNetworkEnabled) {
// no network provider is enabled
} else {
this.canGetLocation = true;
// First get location from Network Provider
if (isNetworkEnabled) {
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("Network", "Network");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
// if GPS Enabled get lat/long using GPS Services
if (isGPSEnabled) {
if (location == null) {
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
Log.d("GPS Enabled", "GPS Enabled");
if (locationManager != null) {
location = locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
return location;
}
/**
* Stop using GPS listener
* Calling this function will stop using GPS in your app
* */
public void stopUsingGPS(){
if(locationManager != null){
locationManager.removeUpdates(GPSTracker.this);
}
}
/**
* Function to get latitude
* */
public double getLatitude(){
if(location != null){
latitude = location.getLatitude();
}
// return latitude
return latitude;
}
/**
* Function to get longitude
* */
public double getLongitude(){
if(location != null){
longitude = location.getLongitude();
}
// return longitude
return longitude;
}
/**
* Function to check GPS/wifi enabled
* @return boolean
* */
public boolean canGetLocation() {
return this.canGetLocation;
}
/**
* Function to show settings alert dialog
* On pressing Settings button will lauch Settings Options
* */
public void showSettingsAlert(){
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
// Setting Dialog Title
alertDialog.setTitle("GPS is settings");
// Setting Dialog Message
alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");
// On pressing Settings button
alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,int which) {
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
mContext.startActivity(intent);
}
});
// on pressing cancel button
alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
// Showing Alert Message
alertDialog.show();
}
@Override
public void onLocationChanged(Location location) {
}
@Override
public void onProviderDisabled(String provider) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public IBinder onBind(Intent arg0) {
return null;
}
}
我想这样做的是让用户打开GPS，然后只调用线程code和适配器设置。我是新来的Android，请考虑到这一点。谢谢。
What I would like to do is ask user to turn on GPS and then only call the thread code and set the adapter. I am new to Android, please take that into consideration. Thank you.
推荐答案
正确的方法做，这是正确实现onLocationChanged - 当你有一个位置，这个功能将被调用。一旦你得到一个良好的precision位置，可以通知您的主要活动。
当然，这应当在单独的线程中运行。
The proper way to do this is to properly implement onLocationChanged - this function will be called when you have a location. Once you get location with good precision, you can notify your main activity. Of course, this should be running in a separate thread.
这篇关于等到GPS位置retrived为ListActivity的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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