GPSTracker课程
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 onStatusChanged(String provider, int status, Bundle extras) {
}
@Override
public void onProviderDisabled(String provider) {
}
@Override
public void onProviderEnabled(String provider) {
}
@Nullable
@Override
public IBinder onBind(Intent intent) {
return null;
}
}
-------------------------------------------------------------------------------
MainActivity Class
public class MainActivity extends AppCompatActivity {
Button btnShowLocation;
private static final int REQUEST_CODE_PERMISSION = 2;
String mPermission = Manifest.permission.ACCESS_FINE_LOCATION;
// GPSTracker class
GPSTracker gps;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
try {
if (ActivityCompat.checkSelfPermission(this, mPermission)
!= MockPackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this, new String[]{mPermission},
REQUEST_CODE_PERMISSION);
// If any permission above not allowed by user, this condition will
//execute every time, else your else part will work
}
} catch (Exception e) {
e.printStackTrace();
}
btnShowLocation = (Button) findViewById(R.id.button);
// show location button click event
btnShowLocation.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
// create class object
gps = new GPSTracker(MainActivity.this);
// check if GPS enabled
if(gps.canGetLocation()){
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
// \n is for new line
Toast.makeText(getApplicationContext(), "Your Location is - \nLat: "
+ latitude + "\nLong: " + longitude, Toast.LENGTH_LONG).show();
}else{
// can't get location
// GPS or Network is not enabled
// Ask user to enable GPS/network in settings
gps.showSettingsAlert();
}
}
});
}
}
我无法正确获取我的位置它总是将GPS位置返回为0和0，我在这里做错了什么？
答案 0 :(得分：0)
文档中提供了很好的示例：https://developer.android.com/reference/android/location/LocationManager.html。还有一个新版本 - FusedLocationsApi。我最近使用Locationmanager进行GPS工作，希望它会有所帮助：
/** * This is an implementation of reader, which track use movement by GPS using old * LocationManager (there is another version for FusedLocationAPIs. * This class doesn't check if GPS is enabled - it is assumed to be enabled by default and * should be checked by code, using this class first. It is so, because both * LocationManager and version using FusedLocationApi prompt to enable GPS in the same manner. */ public class LocationManagerReader extends SensorReader implements LocationListener {
// update location at least every second
private static final long MINIMAL_UPDATE_TIME = 1000;
// or at east when user move to 10 meters.
private static final long MINIMAL_UPDATE_DISTANCE = 10;
private LocationManager locationManager;
public LocationManagerReader(Context context) {
super(context);
locationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
}
/**
* Register this reader as LocationManager to listen for GPS updates with defined
* minimal update time and accuracy.
*/
@Override
protected void startPollingHardwareSensor() {
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,
MINIMAL_UPDATE_TIME, MINIMAL_UPDATE_DISTANCE, this);
}
/**
* Unsubscribe from location updates.
*/
@Override
protected void stopPollingHardwareSensor() {
locationManager.removeUpdates(this);
}
/**
* Inherited from LocationListener
*/
/**
* Process new location in a background
* @param location
*/
@Override
public void onLocationChanged(Location location) {
Observable.defer(() -> Observable.just(location))
.subscribeOn(Schedulers.computation())
.subscribe(loc -> processLocationUpdate(loc));
}
/**
* We're not interested in monitoring changes in gps state, need location updates only
* @param provider
* @param status
* @param extras
*/
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
/**
* We need a high accuracy, that is why use single GPS provider, network is not used -
* don't track changes in provider state
*
* @param provider
*/
@Override
public void onProviderEnabled(String provider) {
}
@Override
public void onProviderDisabled(String provider) {
}
/**
* get current time in nanoseconds and save latitude and longitude as values of reading.
* When we have reading, give it to base class for further processing
* @param location
*/
private void processLocationUpdate(Location location) {
long timeStamp = System.nanoTime();
double lat = location.getLatitude();
double lon = location.getLongitude();
Reading reading = new Reading();
reading.timestamp = timeStamp;
reading.values[0] = lat;
reading.values[1] = lon;
getReadingPipe().onNext(reading);
} }