所以我发现这个代码在线帮助在Android上使用GPS，现在我已经有了我的应用程序来查找我的当前位置，如果我的GPS在运行应用程序之前。但我想知道如何在以下情况下找到我的位置： 1.位置已关闭。 2.运行应用程序。 3.从电源切换开启位置。
我用于GPS的代码是：
public class GPSTracker extends Service implements LocationListener {
// Get Class Name
private static String TAG = GPSTracker.class.getName();
private final Context mContext;
// flag for GPS Status
boolean isGPSEnabled = false;
// flag for network status
boolean isNetworkEnabled = false;
// flag for GPS Tracking is enabled
boolean isGPSTrackingEnabled = false;
Location location;
double latitude;
double longitude;
// How many Geocoder should return our GPSTracker
int geocoderMaxResults = 1;
// The minimum distance to change updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 1; // 10 meters
// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 1000 ; // 1 minute
// Declaring a Location Manager
protected LocationManager locationManager;
// Store LocationManager.GPS_PROVIDER or LocationManager.NETWORK_PROVIDER information
private String provider_info;
public GPSTracker(Context context) {
this.mContext = context;
getLocation();
}
/**
* Try to get my current location by GPS or Network Provider
*/
public void 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);
// Try to get location if you GPS Service is enabled
if (isGPSEnabled) {
this.isGPSTrackingEnabled = true;
Log.d(TAG, "Application use GPS Service");
/*
* This provider determines location using
* satellites. Depending on conditions, this provider may take a while to return
* a location fix.
*/
provider_info = LocationManager.GPS_PROVIDER;
} else if (isNetworkEnabled) { // Try to get location if you Network Service is enabled
this.isGPSTrackingEnabled = true;
Log.d(TAG, "Application use Network State to get GPS coordinates");
/*
* This provider determines location based on
* availability of cell tower and WiFi access points. Results are retrieved
* by means of a network lookup.
*/
provider_info = LocationManager.NETWORK_PROVIDER;
}
// Application can use GPS or Network Provider
if (!provider_info.isEmpty()) {
locationManager.requestLocationUpdates(
provider_info,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES,
this
);
if (locationManager != null) {
location = locationManager.getLastKnownLocation(provider_info);
updateGPSCoordinates();
}
}
}
catch (Exception e)
{
//e.printStackTrace();
Log.e(TAG, "Impossible to connect to LocationManager", e);
}
}
/**
* Update GPSTracker latitude and longitude
*/
public void updateGPSCoordinates() {
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
}
}
/**
* GPSTracker latitude getter and setter
* @return latitude
*/
public double getLatitude() {
if (location != null) {
latitude = location.getLatitude();
}
return latitude;
}
/**
* GPSTracker longitude getter and setter
* @return
*/
public double getLongitude() {
if (location != null) {
longitude = location.getLongitude();
}
return longitude;
}
/**
* GPSTracker isGPSTrackingEnabled getter.
* Check GPS/wifi is enabled
*/
public boolean getIsGPSTrackingEnabled() {
return this.isGPSTrackingEnabled;
}
/**
* Stop using GPS listener
* Calling this method will stop using GPS in your app
*/
public void stopUsingGPS() {
if (locationManager != null) {
locationManager.removeUpdates(GPSTracker.this);
}
}
/**
* Function to show settings alert dialog
*/
public void showSettingsAlert() {
AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);
//Setting Dialog Title
alertDialog.setTitle("GPS Disabled");
//Setting Dialog Message
alertDialog.setMessage("To find the restaurants nearest to you, please turn on your GPS");
//On Pressing Setting button
alertDialog.setPositiveButton(R.string.action_settings, new DialogInterface.OnClickListener() {
@Override
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() {
@Override
public void onClick(DialogInterface dialog, int which)
{
dialog.cancel();
}
});
alertDialog.show();
}
/**
* Get list of address by latitude and longitude
* @return null or List<Address>
*/
public List<Address> getGeocoderAddress(Context context) {
if (location != null) {
Geocoder geocoder = new Geocoder(context, Locale.ENGLISH);
try {
/**
* Geocoder.getFromLocation - Returns an array of Addresses
* that are known to describe the area immediately surrounding the given latitude and longitude.
*/
List<Address> addresses = geocoder.getFromLocation(latitude, longitude, this.geocoderMaxResults);
return addresses;
} catch (IOException e) {
//e.printStackTrace();
Log.e(TAG, "Impossible to connect to Geocoder", e);
}
}
return null;
}
/**
* Try to get AddressLine
* @return null or addressLine
*/
public String getAddressLine(Context context) {
List<Address> addresses = getGeocoderAddress(context);
if (addresses != null && addresses.size() > 0) {
Address address = addresses.get(0);
String addressLine = address.getAddressLine(0);
return addressLine;
} else {
return null;
}
}
/**
* Try to get Locality
* @return null or locality
*/
public String getLocality(Context context) {
List<Address> addresses = getGeocoderAddress(context);
if (addresses != null && addresses.size() > 0) {
Address address = addresses.get(0);
String locality = address.getLocality();
return locality;
}
else {
return null;
}
}
/**
* Try to get Postal Code
* @return null or postalCode
*/
public String getPostalCode(Context context) {
List<Address> addresses = getGeocoderAddress(context);
if (addresses != null && addresses.size() > 0) {
Address address = addresses.get(0);
String postalCode = address.getPostalCode();
return postalCode;
} else {
return null;
}
}
/**
* Try to get CountryName
* @return null or postalCode
*/
public String getCountryName(Context context) {
List<Address> addresses = getGeocoderAddress(context);
if (addresses != null && addresses.size() > 0) {
Address address = addresses.get(0);
String countryName = address.getCountryName();
return countryName;
} else {
return null;
}
}
@Override
public void onLocationChanged(Location location) {
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
@Nullable
@Override
public IBinder onBind(Intent intent) {
return null;
}
}
同样在OnCreate方法中，我按如下方式实例化了类：
gpsTracker = new GPSTracker(this){
@Override
public void onLocationChanged(Location location) {
//do stuff
}
答案 0 :(得分：0)
好吧我明白了。出于某种原因，没有network_provider，因为gps_provider关闭了，它就会到达行
if (!provider_info.isEmpty()) {
locationManager.requestLocationUpdates(
provider_info,
MIN_TIME_BW_UPDATES,
MIN_DISTANCE_CHANGE_FOR_UPDATES,
this
);
并且只是传递它而不运行requestLocationUpdates，因此不允许gpsTracker对象被通知是否有任何更新。我所做的只是我做了
String provider_info = LocationManager.GPS_LOCATION;