在手机上获取当前位置，不起作用？ [安卓]

Question

到目前为止。它应该在两个单独的文本视图中将当前位置显示为纬度和经度。

我已经在模拟器和真正的 android 手机上尝试过，但两者都不起作用。没有任何反应，文本视图不显示任何坐标。也没有错误。

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

private static final int LOCATION_REQUEST_INTERVAL = 60000;
private static final int LOCATION_REQUEST_FASTEST = 15000;
private static final int MY_PERMISSION_REQUEST_READ_COARSE_LOCATION = 102;
private TextView latitudeTextView;
private TextView longitudeTextView;
private ImageButton imageButton;
private GoogleApiClient googleApiClient;
private LocationRequest locationRequest;
private FusedLocationProviderApi fusedLocationProviderApi = LocationServices.FusedLocationApi;
private double mLatitude;
private double mLongitude;

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

    latitudeTextView = (TextView) findViewById(R.id.latitudeTextView);
    longitudeTextView = (TextView) findViewById(R.id.longitudeTextView);
    imageButton = (ImageButton) findViewById(R.id.imageButton);

    googleApiClient = new GoogleApiClient.Builder(this)
            .addApi(LocationServices.API)
            .addConnectionCallbacks(this)
            .addOnConnectionFailedListener(this).build();

    locationRequest = new LocationRequest();
    locationRequest.setInterval(LOCATION_REQUEST_INTERVAL);
    locationRequest.setFastestInterval(LOCATION_REQUEST_FASTEST);
    locationRequest.setPriority(locationRequest.PRIORITY_BALANCED_POWER_ACCURACY);
}

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

private void requestLocationUpdates() {
    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        ActivityCompat.requestPermissions(this,
                new String[]{Manifest.permission.ACCESS_COARSE_LOCATION,Manifest.permission.ACCESS_FINE_LOCATION},
                MY_PERMISSION_REQUEST_READ_COARSE_LOCATION);

        return;
    }
    LocationServices.FusedLocationApi.requestLocationUpdates(googleApiClient, locationRequest, this);
}

@Override
public void onConnectionSuspended(int i) {

}

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

}

@Override
public void onLocationChanged(Location location) {
    mLatitude = location.getLatitude();
    mLongitude = location.getLongitude();
    latitudeTextView.setText(String.valueOf(mLatitude));
    longitudeTextView.setText(String.valueOf(mLongitude));
}

@Override
protected void onStart() {
    super.onStart();
    googleApiClient.connect();
}

@Override
protected void onStop() {
    super.onStop();
    googleApiClient.disconnect();
}

@Override
protected void onResume() {
    super.onResume();
    if(googleApiClient.isConnected())
        requestLocationUpdates();;
}

@Override
protected void onPause() {
    super.onPause();
    LocationServices.FusedLocationApi.removeLocationUpdates(googleApiClient,this);
}

}

为什么它不起作用？我遵循了一些指南，其中之一是 android 开发者指南。

您有什么想法或建议吗？

感谢您的任何意见。

Answer 1

根据我的经验，模拟器不适用于PRIORITY_BALANCED_POWER_ACCURACY，但需要PRIORITY_HIGH_ACCURACY。

更改代码行

locationRequest.setPriority(locationRequest.PRIORITY_BALANCED_POWER_ACCURACY);

到

LocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);

我还注意到权限请求对话框仅授予粗略位置的权限。我会把它改成好的位置。更改代码行：

new String[] Manifest.permission.ACCESS_COARSE_LOCATION,Manifest.permission.ACCESS_FINE_LOCATION}, MY_PERMISSION_REQUEST_READ_COARSE_LOCATION);

到

requestPermissions(new
         String[]{Manifest.permission.ACCESS_FINE_LOCATION},
         MY_PERMISSION_REQUEST_FINE_LOCATION);

并为MY_PERMISSION_REQUEST_FINE_LOCATION定义一个字符串值

最后，检查设备或模拟器是否已授予位置权限。转到“设置”->“应用程序”并检查该应用程序是否正在使用定位服务。如果没有，请点击“权限”并打开服务。

Answer 2

创建一个类GpsTracker.java：

import android.app.AlertDialog;
import android.app.Service;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.location.GpsStatus;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.IBinder;
import android.provider.Settings;
import android.util.Log;

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 = 1000; // 10 meters

    // The minimum time between updates in milliseconds
    private static final long MIN_TIME_BW_UPDATES =  100000 * 60 * 1; // 5 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
                //showSettingsAlert();

            } else {
                this.canGetLocation = true;
                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
                else {
                    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();
            System.exit(0);

            }
        });

        // 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;
    }

}

现在您可以获取 GpsTracker.java 的位置创建实例，例如：

GPSTracker  gpstracker=new GPSTracker(EditProfile.this);
double lat=gpstracker.getLatitude();
double longitude=gpstracker.getLongitude();