位置始終為空

Question

這是我的安卓項目。 該應用程序顯示有關當前位置的信息。
但是，該應用程序始終顯示該位置為空。 我已經搜索了很多，但仍然無法找到解決方案或無法實施該解決方案。

這是我的 MainActivity 代碼，

package com.learning.pranavjain.hikerswatch;

import android.Manifest;
import android.app.Activity;
import android.content.Context;
import android.content.pm.PackageManager;
import android.location.Address;
import android.location.Criteria;
import android.location.Geocoder;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.support.v4.app.ActivityCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.WindowManager;
import android.widget.TextView;

import java.io.IOException; 
import java.util.List;
import java.util.Locale;

public class MainActivity extends Activity implements LocationListener {

LocationManager locationManager;
String provider;
String sLatitude;
String sLongitude;
String sAccuracy;
String sSpeed;
String sAltitude;
TextView addressTV;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    //Hiding the status bar
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
            WindowManager.LayoutParams.FLAG_FULLSCREEN);
    setContentView(R.layout.activity_main);

    locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    provider = locationManager.getBestProvider(new Criteria(),false);

    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        // TODO: Consider calling
        //    ActivityCompat#requestPermissions
        // here to request the missing permissions, and then overriding
        //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
        //                                          int[] grantResults)
        // to handle the case where the user grants the permission. See the documentation
        // for ActivityCompat#requestPermissions for more details.
        return;
    }
    locationManager.requestLocationUpdates(provider,400,1,this);
    location = locationManager.getLastKnownLocation(provider);

    if(location==null){
        Log.i("Location1","NULL1");
        Toast.makeText(this,"Location not found",Toast.LENGTH_SHORT).show();
    }

    if(location!=null) {
        onLocationChanged(location);
        Log.i("Location1","Reached here");
    }

}

@Override
protected void onResume() {
    super.onResume();


    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        // TODO: Consider calling
        //    ActivityCompat#requestPermissions
        // here to request the missing permissions, and then overriding
        //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
        //                                          int[] grantResults)
        // to handle the case where the user grants the permission. See the documentation
        // for ActivityCompat#requestPermissions for more details.
        return;
    }
    locationManager.requestLocationUpdates(provider, 400, 1, this);
}

@Override
public void onLocationChanged(Location location) {



    Double lat = location.getLatitude();
    Double lng = location.getLongitude();
    Float acc = location.getAccuracy();
    Float spe = location.getSpeed();
    Double alt = location.getAltitude();

    Log.i("Location","reached here");

    TextView latitude = (TextView) findViewById(R.id.latitude);
    TextView longitude = (TextView) findViewById(R.id.longitude);
    TextView accuracy = (TextView) findViewById(R.id.accuracy);
    TextView speed = (TextView) findViewById(R.id.speed);
    TextView altitude = (TextView) findViewById(R.id.altitude);
    addressTV = (TextView) findViewById(R.id.address);

    sLatitude = latitude.getText().toString();
    sLongitude = longitude.getText().toString();
    sAccuracy = accuracy.getText().toString();
    sSpeed = speed.getText().toString();
    sAltitude = altitude.getText().toString();

    sLatitude += Double.toString(lat);
    sLongitude += Double.toString(lng);
    sAccuracy += Double.toString(acc);
    sSpeed += Double.toString(spe);
    sAltitude += Double.toString(alt);

    latitude.setText(sLatitude);
    longitude.setText(sLongitude);
    accuracy.setText(sAccuracy);
    speed.setText(sSpeed);
    altitude.setText(sAltitude);

    Geocoder geocoder = new Geocoder(getApplicationContext(), Locale.getDefault());

    try {
        List<Address> listAddresses = geocoder.getFromLocation(lat, lng, 1);

        if (listAddresses != null && listAddresses.size() > 0 ) {

            Log.i("PlaceInfo", listAddresses.get(0).toString());

            String addressHolder = "";

            for (int i = 0; i <= listAddresses.get(0).getMaxAddressLineIndex(); i++) {

                addressHolder += listAddresses.get(0).getAddressLine(i) + "\n";

            }

            addressTV.setText("Address:\n" + addressHolder);

        }

    } catch (IOException e) {
        e.printStackTrace();
    }

    Log.i("Location:", String.valueOf(lat));
    Log.i("Location:", lng.toString());

}

@Override
public void onStatusChanged(String provider, int status, Bundle extras) {

}

@Override
public void onProviderEnabled(String provider) {

}

@Override
public void onProviderDisabled(String provider) {

}

@Override
protected void onPause() {
    super.onPause();

    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        // TODO: Consider calling
        //    ActivityCompat#requestPermissions
        // here to request the missing permissions, and then overriding
        //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
        //                                          int[] grantResults)
        // to handle the case where the user grants the permission. See the documentation
        // for ActivityCompat#requestPermissions for more details.
        return;
    }
    locationManager.removeUpdates(this);

 }
}

這是我的清單代碼，

<?xml version="1.0" encoding="utf-8"?>

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-feature android:name="android.hardware.location.network" />
<uses-feature android:name="android.hardware.location.gps" />

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity android:name=".MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

整個項目可以在這里找到（GitHub）

Answer 1

getLastKnownLocation 返回一個緩存值。 它不會打開位置跟蹤。 因此，除非某些其他應用程序最近打開了位置跟蹤，否則它不會為您提供很好的價值並返回 null。 如果你想要一個有保證的值，你需要通過requestLocationUpdates或requestSingleUpdate打開位置跟蹤。 其中任何一個都會告訴操作系統找出您當前的位置，並在完成后給您一個回調。 請注意，回調可能需要一些時間才能被調用 - 特別是對於 GPS。 如果手機無法獲取網絡信息/GPS 衛星數據，則永遠不會進行回撥。

Answer 2

您可以查看RxGpsService （使用 RxJava 檢索 GPS 位置和路線統計數據的 Android 服務）。 它檢索一個RouteStats對象，其中包含當前速度、距離、經過的時間和航點。

Answer 3

嗨，為什么要嘗試使用getLastKnownLocation 。它會返回您以前的緯度和經度，並且可能需要一些時間來更新最后已知的位置。 很可能它在您的位置之后重新運行您 null。

我只是在向您推薦谷歌 Fused api以獲取任何類型的更新或當前位置。它非常准確。

你如何在你的項目中融合 api。看我給你一個小例子。

第 1 步：創建這個類 GoogleLocationService.java

public class GoogleLocationService {
private GoogleServicesCallbacks callbacks = new GoogleServicesCallbacks();
LocationUpdateListener locationUpdateListener;
Context activity;
protected GoogleApiClient mGoogleApiClient;
protected LocationRequest mLocationRequest;

public static final long UPDATE_INTERVAL_IN_MILLISECONDS = 30000;


public GoogleLocationService(Context activity, LocationUpdateListener locationUpdateListener) {
    this.locationUpdateListener = locationUpdateListener;
    this.activity = activity;
    buildGoogleApiClient();
}

protected synchronized void buildGoogleApiClient() {
    //Log.i(TAG, "Building GoogleApiClient");
    mGoogleApiClient = new GoogleApiClient.Builder(activity)
            .addConnectionCallbacks(callbacks)
            .addOnConnectionFailedListener(callbacks)
            .addApi(LocationServices.API)
            .build();
    createLocationRequest();
    mGoogleApiClient.connect();
}

protected void createLocationRequest() {
    mLocationRequest = new LocationRequest();
    mLocationRequest.setInterval(UPDATE_INTERVAL_IN_MILLISECONDS);
    mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);

}

private class GoogleServicesCallbacks implements GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener, LocationListener {

    @Override
    public void onConnected(Bundle bundle) {
        startLocationUpdates();
    }

    @Override
    public void onConnectionSuspended(int i) {
        mGoogleApiClient.connect();
    }

    @Override
    public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {

        if (connectionResult.getErrorCode() == ConnectionResult.SERVICE_VERSION_UPDATE_REQUIRED) {
            Toast.makeText(activity, "Google play service not updated", Toast.LENGTH_LONG).show();

        }
        locationUpdateListener.cannotReceiveLocationUpdates();
    }

    @Override
    public void onLocationChanged(Location location) {
        if (location.hasAccuracy()) {
            if (location.getAccuracy() < 30) {
                locationUpdateListener.updateLocation(location);
            }
        }
    }
}

private static boolean locationEnabled(Context context) {
    boolean gps_enabled = false;
    LocationManager lm = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
    try {
        gps_enabled = lm.isProviderEnabled(LocationManager.GPS_PROVIDER);
    } catch (Exception ex) {
        ex.printStackTrace();
    }
    return gps_enabled;
}

private boolean servicesConnected(Context context) {
    return isPackageInstalled(GooglePlayServicesUtil.GOOGLE_PLAY_STORE_PACKAGE, context);
}

private boolean isPackageInstalled(String packagename, Context context) {
    PackageManager pm = context.getPackageManager();
    try {
        pm.getPackageInfo(packagename, PackageManager.GET_ACTIVITIES);
        return true;
    } catch (PackageManager.NameNotFoundException e) {
        e.printStackTrace();
        return false;
    }
}


public void startUpdates() {
    /*
     * Connect the client. Don't re-start any requests here; instead, wait
     * for onResume()
     */
    if (servicesConnected(activity)) {
        if (locationEnabled(activity)) {
            locationUpdateListener.canReceiveLocationUpdates();
            startLocationUpdates();
        } else {
            locationUpdateListener.cannotReceiveLocationUpdates();
            Toast.makeText(activity, "Unable to get your location.Please turn on your device Gps", Toast.LENGTH_LONG).show();
        }
    } else {
        locationUpdateListener.cannotReceiveLocationUpdates();
        Toast.makeText(activity, "Google play service not available", Toast.LENGTH_LONG).show();
    }
}

//stop location updates
public void stopUpdates() {
    stopLocationUpdates();
}

//start location updates
private void startLocationUpdates() {

    if (checkSelfPermission(activity, ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && checkSelfPermission(activity, ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        return;
    }
    if (mGoogleApiClient.isConnected()) {
        LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, callbacks);
    }
}

public void stopLocationUpdates() {
    if (mGoogleApiClient.isConnected()) {
        LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, callbacks);
    }
}

public void startGoogleApi() {
    mGoogleApiClient.connect();
}

public void closeGoogleApi() {
    mGoogleApiClient.disconnect();
}

 }

第2步。 制作這個接口 LocationUpdateListener.java

 public interface LocationUpdateListener {

/**
 * Called immediately the service starts if the service can obtain location
 */
void canReceiveLocationUpdates();

/**
 * Called immediately the service tries to start if it cannot obtain location - eg the user has disabled wireless and
 */
void cannotReceiveLocationUpdates();

/**
 * Called whenever the location has changed (at least non-trivially)
 * @param location
 */
void updateLocation(Location location);

/**
 * Called when GoogleLocationServices detects that the device has moved to a new location.
 * @param localityName The name of the locality (somewhere below street but above area).
 */
void updateLocationName(String localityName, Location location);
}

第 3 步。在您想要獲取位置的地方使用這段代碼

public class MainActivity extends ActionBarActivity {

private GoogleLocationService googleLocationService;

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

    googleLocationService = new GoogleLocationService(context, new LocationUpdateListener() {
    @Override
    public void canReceiveLocationUpdates() {
    }

    @Override
    public void cannotReceiveLocationUpdates() {
    }

    //update location to our servers for tracking purpose
    @Override
    public void updateLocation(Location location) {
        if (location != null ) {
            Timber.e("updated location %1$s %2$s", location.getLatitude(), location.getLongitude());

        }
    }

    @Override
    public void updateLocationName(String localityName, Location location) {

        googleLocationService.stopLocationUpdates();
    }
});
googleLocationService.startUpdates();


}

@Override
public void onDestroy() {
    super.onDestroy();
if (googleLocationService != null) {
    googleLocationService.stopLocationUpdates();
}

}
}

希望這會幫助你。

Answer 4

您可以使用此代碼

主活動.java

import android.Manifest;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.IntentSender;
import android.content.pm.PackageManager;
import android.location.Location;
import android.net.Uri;
import android.provider.Settings;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;
import android.widget.Toast;

import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.common.api.PendingResult;
import com.google.android.gms.common.api.ResultCallback;
import com.google.android.gms.common.api.Status;
import com.google.android.gms.location.LocationListener;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationServices;
import com.google.android.gms.location.LocationSettingsRequest;
import com.google.android.gms.location.LocationSettingsResult;
import com.google.android.gms.location.LocationSettingsStates;
import com.google.android.gms.location.LocationSettingsStatusCodes;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;

import java.text.DateFormat;
import java.util.Date;

public class MainActivity extends AppCompatActivity implements GoogleApiClient.ConnectionCallbacks,
        GoogleApiClient.OnConnectionFailedListener, LocationListener, OnMapReadyCallback {

    private GoogleApiClient mGoogleApiClient;
    private LocationRequest mLocationRequest;
    private Location mCurrentLocation;
    private String mLocationUpdatedDate;

    private TextView mLatitude;
    private TextView mLongitude;
    private TextView mDateText;

    private GoogleMap mMap;
    private Marker mCurrentMarker;

    private final int MY_PERMISSIONS_REQUEST_READ_LOCATION = 100;
    private final int REQUEST_CHECK_SETTINGS = 101;
    private final int REQUEST_PERMISSION_SETTING = 102;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mLatitude = (TextView) findViewById(R.id.latText);
        mLongitude = (TextView) findViewById(R.id.longText);
        mDateText = (TextView) findViewById(R.id.dateText);

        if (mGoogleApiClient == null) {
            mGoogleApiClient = new GoogleApiClient.Builder(this)
                    .addConnectionCallbacks(this)
                    .addOnConnectionFailedListener(this)
                    .addApi(LocationServices.API)
                    .build();
        }

        createLocationRequest();

        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map);
        mapFragment.getMapAsync(this);

    }

    private void fetchLocation() {

        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED
                && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
            mCurrentLocation = LocationServices.FusedLocationApi.getLastLocation(
                    mGoogleApiClient);
        }
    }

    private void updateUI() {
        if (mCurrentLocation != null) {
            mLatitude.setText(String.valueOf(mCurrentLocation.getLatitude()));
            mLongitude.setText(String.valueOf(mCurrentLocation.getLongitude()));
            mDateText.setText(mLocationUpdatedDate);
        }
    }


    protected void onStart() {
        mGoogleApiClient.connect();
        super.onStart();
    }

    protected void onStop() {
        mGoogleApiClient.disconnect();
        super.onStop();
    }


    @Override
    public void onConnected(@Nullable Bundle bundle) {
        if (ActivityCompat.checkSelfPermission(MainActivity.this,
                Manifest.permission.ACCESS_COARSE_LOCATION)
                != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(MainActivity.this,
                Manifest.permission.ACCESS_FINE_LOCATION)
                != PackageManager.PERMISSION_GRANTED) {

            ActivityCompat.requestPermissions(MainActivity.this,
                    new String[]{Manifest.permission.ACCESS_COARSE_LOCATION},
                    MY_PERMISSIONS_REQUEST_READ_LOCATION);

        } else {
            fetchLocation();
            updateUI();

            startLocationUpdates();

        }

    }

    @Override
    public void onConnectionSuspended(int i) {

    }

    @Override
    public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {

    }


    protected void createLocationRequest() {
        mLocationRequest = new LocationRequest();
        mLocationRequest.setInterval(10000);
        mLocationRequest.setFastestInterval(5000);
        mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);

        LocationSettingsRequest.Builder builder = new LocationSettingsRequest.Builder()
                .addLocationRequest(mLocationRequest);

        PendingResult<LocationSettingsResult> result =
                LocationServices.SettingsApi.checkLocationSettings(mGoogleApiClient,
                        builder.build());


        result.setResultCallback(new ResultCallback<LocationSettingsResult>() {
            @Override
            public void onResult(@NonNull LocationSettingsResult result) {
                final Status status = result.getStatus();
                //   final LocationSettingsStates  = result.getLocationSettingsStates();
                switch (status.getStatusCode()) {
                    case LocationSettingsStatusCodes.SUCCESS:
                        // All location settings are satisfied. The client can
                        // initialize location requests here.

                        break;
                    case LocationSettingsStatusCodes.RESOLUTION_REQUIRED:
                        // Location settings are not satisfied, but this can be fixed
                        // by showing the user a dialog.
                        try {
                            // Show the dialog by calling startResolutionForResult(),
                            // and check the result in onActivityResult().
                            status.startResolutionForResult(
                                    MainActivity.this,
                                    REQUEST_CHECK_SETTINGS);
                        } catch (IntentSender.SendIntentException e) {
                            // Ignore the error.
                        }
                        break;
                    case LocationSettingsStatusCodes.SETTINGS_CHANGE_UNAVAILABLE:
                        // Location settings are not satisfied. However, we have no way
                        // to fix the settings so we won't show the dialog.

                        break;
                }
            }
        });

    }


    protected void startLocationUpdates() {
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED
                && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED) {

            LocationServices.FusedLocationApi.requestLocationUpdates(
                    mGoogleApiClient, mLocationRequest, this);
        }
    }

    protected void stopLocationUpdates() {
        LocationServices.FusedLocationApi.removeLocationUpdates(
                mGoogleApiClient, this);
    }


    @Override
    protected void onPause() {
        if (!mGoogleApiClient.isConnected())
            stopLocationUpdates();
        super.onPause();

    }

    @Override
    protected void onResume() {
        if (mGoogleApiClient.isConnected()) {
            startLocationUpdates();
        }
        super.onResume();

    }

    @Override
    public void onRequestPermissionsResult(int requestCode,
                                           String permissions[], int[] grantResults) {
        switch (requestCode) {
            case MY_PERMISSIONS_REQUEST_READ_LOCATION: {
                // If request is cancelled, the result arrays are empty.
                //   String permission = permissions[0];
                for (int i = 0, len = permissions.length; i < len; i++) {
                    String permission = permissions[0];
                    if (grantResults.length > 0
                            && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                        fetchLocation();
                        updateUI();

                    } else {

                        if (!ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this, permission)) {

                            // user denied WITH never ask again
                            showSettingDialog();


                        } else if (Manifest.permission.ACCESS_COARSE_LOCATION.equals(permission)) {
                            showPermissionDialog();
                            // user denied WITHOUT never ask again
                            // this is a good place to explain the user
                            // why you need the permission and ask if he want
                            // to accept it (the rationale)
                        }


                    }
                    return;
                }
            }

            // other 'case' lines to check for other
            // permissions this app might request
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {

        if (requestCode == REQUEST_PERMISSION_SETTING) {
            // updateUI(fetchLocation());

            Toast.makeText(MainActivity.this, "RequestCode = " + requestCode + "  ResultCode = " + resultCode, Toast.LENGTH_SHORT).show();
        }
    }

    @Override
    public void onLocationChanged(Location location) {
        mCurrentLocation = location;
        mLocationUpdatedDate = DateFormat.getTimeInstance().format(new Date());
        updateUI();

        if (mCurrentMarker != null) {
            mCurrentMarker.remove();

        }

        if (mMap != null) {
           /* LatLng currentPosition = new LatLng(mCurrentLocation.getLatitude(), mCurrentLocation.getLongitude());
            mMap.addMarker(new MarkerOptions().position(currentPosition).title("Myself"));
            mMap.moveCamera(CameraUpdateFactory.newLatLng(currentPosition));*/

            LatLng latLng = new LatLng(mCurrentLocation.getLatitude(), mCurrentLocation.getLongitude());
            mCurrentMarker = mMap.addMarker(new MarkerOptions().position(latLng).title("Abhishek").icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_BLUE)));
            // Showing the current location in Google Map
            mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));

            // Zoom in the Google Map
            mMap.animateCamera(CameraUpdateFactory.zoomTo(20));
        }


    }


    private void showPermissionDialog() {

        final AlertDialog dialog = new AlertDialog.Builder(MainActivity.this).create();
        dialog.setButton(AlertDialog.BUTTON_POSITIVE, "Ok", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialogInterface, int i) {

                dialog.cancel();
                ActivityCompat.requestPermissions(MainActivity.this,
                        new String[]{Manifest.permission.ACCESS_COARSE_LOCATION},
                        MY_PERMISSIONS_REQUEST_READ_LOCATION);

            }
        });
        dialog.setButton(AlertDialog.BUTTON_NEGATIVE, "Cancel", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialogInterface, int i) {
                dialog.cancel();
            }
        });

        dialog.setTitle("Location explaination");
        dialog.setMessage("Location permission is taken so that we can provide you with better service");
        dialog.show();
    }

    private void showSettingDialog() {

        final AlertDialog dialog = new AlertDialog.Builder(MainActivity.this).create();
        dialog.setButton(AlertDialog.BUTTON_POSITIVE, "Ok", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialogInterface, int i) {


                Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
                Uri uri = Uri.fromParts("package", getPackageName(), null);
                intent.setData(uri);
                startActivityForResult(intent, REQUEST_PERMISSION_SETTING);
                dialog.cancel();

            }
        });
        dialog.setButton(AlertDialog.BUTTON_NEGATIVE, "Cancel", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialogInterface, int i) {
                dialog.cancel();
            }
        });

        dialog.setTitle("Permission Denied");
        dialog.setMessage("Please enable location from your app setting screen");
        dialog.show();
    }

    @Override
    public void onMapReady(GoogleMap googleMap) {


        mMap = googleMap;
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED &&
                ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
            mMap.setMyLocationEnabled(true);
        }



        // Add a marker in Sydney and move the camera
        if(mCurrentLocation != null) {
            LatLng currentPosition = new LatLng(mCurrentLocation.getLatitude(), mCurrentLocation.getLongitude());
            mMap.addMarker(new MarkerOptions().position(currentPosition).title("Myself"));
            mMap.moveCamera(CameraUpdateFactory.newLatLng(currentPosition));
        }
    }
}

活動主

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="abhishek.com.testing.MainActivity">


    <fragment
        android:id="@+id/map"
        android:name="com.google.android.gms.maps.SupportMapFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context="abhishek.com.testing.MapsActivity" />



    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"
        android:gravity="center_horizontal"
        android:weightSum="3">

        <TextView
            android:id="@+id/latText"
            android:layout_width="wrap_content"
            android:layout_height="0dp"
            android:layout_weight="1"
            android:text="Latitude" />


        <TextView
            android:id="@+id/longText"
            android:layout_width="wrap_content"
            android:layout_height="0dp"
            android:layout_weight="1"
            android:text="Longitude" />


        <TextView
            android:id="@+id/dateText"
            android:layout_width="wrap_content"
            android:layout_height="0dp"
            android:layout_weight="1"
            android:text="Updated at"/>

    </LinearLayout>



</RelativeLayout>