如何在android中获取纬度和经度

Question

我尝试制作一个祈祷时间表应用程序，但是当系统想要获取纬度和经度值时遇到问题，在初始程序中我已在主要活动中放置了启用 GPS 的清单权限

@Override
        public void onClick(View view) {
            if (ActivityCompat.checkSelfPermission(UtamaActivity.this,Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED
                    && ActivityCompat.checkSelfPermission(UtamaActivity.this,Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED){
                ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION},44);
                ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.ACCESS_COARSE_LOCATION},44);
            } else {
                Intent jadwalSholat = new Intent(MainActivity.this, TimePrayActivity.class);
                startActivity(jadwalSholat);
            }
        }
    });

我已经在manifest中添加了ACCESS_FINE和ACCESS_COARSE权限，但是在进行活动时间祈祷时，GPS不会自动启动，用户必须手动启动GPS ，即使开启了 GPS 和 Internet 连接，程序仍然无法获取纬度和经度值。

时间祈祷活动：

    public class JadwalSholatActivity extends AppCompatActivity {
...
    FusedLocationProviderClient providerClient;
    private double latitude, longitude;
    private static final int ACCESS_LOCATION = 1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_jadwal_sholat);

        ...
        providerClient = LocationServices.getFusedLocationProviderClient(this);

        progressBar = findViewById(R.id.barbar);

        checkState();

    }

    private void checkState(){
        final LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
        ConnectivityManager manager = (ConnectivityManager) getApplicationContext().getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = manager.getActiveNetworkInfo();
        if (networkInfo != null){
            if (networkInfo.getType() == ConnectivityManager.TYPE_WIFI || networkInfo.getType() == ConnectivityManager.TYPE_MOBILE){
                if (!locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)){
                    Toast.makeText(this, "Enable your GPS!", Toast.LENGTH_SHORT).show();
                } else {
                    getLocation();
                }
            }
        } else {
            Toast.makeText(this, "No Internet Connection!", Toast.LENGTH_SHORT).show();
        }
    }

    private void getLocation(){
        if (ActivityCompat.checkSelfPermission(this,Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED
                && ActivityCompat.checkSelfPermission(this,Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED){
            return;
        }
        progressBar.setVisibility(View.VISIBLE);
        providerClient.getLastLocation().addOnCompleteListener(new OnCompleteListener<Location>() {
            @Override
            public void onComplete(@NonNull Task<Location> task) {
                Location location = task.getResult();
                if (location != null){
                    Geocoder geocoder = new Geocoder(JadwalSholatActivity.this,Locale.getDefault());
                    try {
                        List<Address> addresses = geocoder.getFromLocation(location.getLatitude(),location.getLongitude(),1);
                        latitude = (double) addresses.get(0).getLatitude();
                        longitude = (double) addresses.get(0).getLongitude();
                        jadwalSholat();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
        });
    }


    private void jadwalSholat(){
        progressBar.setVisibility(View.GONE);
        DateComponents dateComponents = DateComponents.from(new Date());
        **Coordinates coordinates = new Coordinates(latitude,longitude);**
        CalculationParameters parameters = CalculationMethod.MUSLIM_WORLD_LEAGUE.getParameters();

        SimpleDateFormat formats = new SimpleDateFormat("HH:mm");
        formats.setTimeZone(TimeZone.getDefault());

        PrayerTimes prayerTimes = new PrayerTimes(coordinates,dateComponents,parameters);

        ...
    }
}

所以，我遇到的问题很可能是程序没有得到经纬度值，如果还有其他问题，请在 cmets 中告诉他们

Answer 1

GpsTracker.java

     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) {
                    if (ActivityCompat.checkSelfPermission((Activity)mContext, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                        ActivityCompat.requestPermissions((Activity)mContext, new String[]{
                                android.Manifest.permission.ACCESS_FINE_LOCATION
                        }, 10);
                    }
                    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;
    }
}

Activity -AndroidGPSTrackingActivity.java

 public class AndroidGPSTrackingActivity extends Activity {

    Button btnShowLocation;

    // GPSTracker class
    GPSTracker gps;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        btnShowLocation = (Button) findViewById(R.id.btnShowLocation);

        // Show location button click event
        btnShowLocation.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View arg0) {
                // Create class object
                gps = new GPSTracker(AndroidGPSTrackingActivity.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();
                }
            }
        });
    }
}

Layout-main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <Button android:id="@+id/btnShowLocation"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Show Location"
        android:layout_centerVertical="true"
        android:layout_centerHorizontal="true"/>
</RelativeLayout>

AndroidManifest.xml

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.INTERNET" />