我正在开发一个应用程序，该应用程序执行诸如使用相机拍照和查看所拍摄照片的操作。现在，我有一个onclick按钮，它会转到图库中供我选择图像。选择图像后正在将图像加载到活动以及图像的位置。但是，所选照片的位置都相同（当前位置）。
我正在使用它来获取位置。但是无论我选择的图像是我的当前位置。
GPSTRACKER.JAVA
package com.elno.bescomcoe;
import android.Manifest;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.Service;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.location.Address;
import android.location.Geocoder;
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.support.annotation.Nullable;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.util.Log;
import java.io.IOException;
import java.util.List;
import java.util.Locale;
import static android.content.ContentValues.TAG;
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
int geocoderMaxResults = 1;
// 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 mContext) {
this.mContext = mContext;
getLocation();
}
@SuppressLint("MissingPermission")
public Location getLocation() {
try {
locationManager = (LocationManager) mContext
.getSystemService(LOCATION_SERVICE);
// Getting GPS status
isGPSEnabled = locationManager
.isProviderEnabled(LocationManager.GPS_PROVIDER);
System.out.println("GPS : " + isGPSEnabled);
// Getting network status
isNetworkEnabled = locationManager
.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
System.out.println("NETWORK : " + isNetworkEnabled);
if (isGPSEnabled) {
this.isGPSEnabled = true;
}
if (!isGPSEnabled && !isNetworkEnabled) {
// No network provider is enabled
System.out.println("Inside gps and network");
} else {
System.out.println("outside gps and network");
this.canGetLocation = true;
if (isNetworkEnabled) {
//ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 0);
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 latitude/longitude 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/Wi-Fi enabled
* @return boolean
* */
public boolean canGetLocation() {
return this.canGetLocation;
}
/**
* Function to show settings alert dialog.
* On pressing the Settings button it will launch 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 the 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 the cancel button
alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
// Showing Alert Message
alertDialog.show();
}
//Get list of Addresses by latitude and longitude
//return List<Adresses> - list of addresses or null
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;
}
//Get the Address Line
//Return address line or null
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;
}
}
//Get the Locality
//Return the locality or null
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;
}
}
@Nullable
@Override
public IBinder onBind(Intent intent) {
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) {
}
}
而且，这是我要在其中加载所选图像和位置的活动。
package com.elno.bescomcoe;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
public class ViewGalleryAcitvity extends AppCompatActivity {
private TextView LocationTextView;
private ImageView SelectedImageView;
GPSTracker gps;
double latitude ;
double longitude;
String country;
String city;
String postalcode;
String addressline;
Uri imageUri;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_view_gallery);
LocationTextView = findViewById(R.id.LoctextView);
SelectedImageView = findViewById(R.id.selectedimage);
Bundle bundle = getIntent().getExtras();
if(bundle != null){
imageUri = Uri.parse(bundle.getString("picture"));
SelectedImageView.setImageURI(imageUri);
gps = new GPSTracker(getApplicationContext());
if(gps.canGetLocation())
{
latitude = gps.getLatitude();
longitude = gps.getLongitude();
country = gps.getCountryName(this);
city = gps.getLocality(this);
postalcode = gps.getPostalCode(this);
addressline = gps.getAddressLine(this);
Toast.makeText(getApplicationContext(), "Your Location is - \nLat: " + latitude + "\nLong: " + longitude, Toast.LENGTH_LONG).show();
LocationTextView.setText("Latitude - "+latitude+"\nLongitude - "+longitude);
} else {
// Can't get location.
}
}
else {
//Bundle is empty
}
}
}
现在，我需要有关如何获取拍摄图像的位置而不只是我当前位置的帮助。
答案 0 :(得分：0)
您可以使用ExifInterface
获取图像属性示例：
ExifInterface exif = new ExifInterface(filepath);
String LATITUDE = exif.getAttribute(ExifInterface.TAG_GPS_LATITUDE);
String LATITUDE_REF = exif.getAttribute(ExifInterface.TAG_GPS_LATITUDE_REF);
String LONGITUDE = exif.getAttribute(ExifInterface.TAG_GPS_LONGITUDE);
String LONGITUDE_REF = exif.getAttribute(ExifInterface.TAG_GPS_LONGITUDE_REF);
或
ExifInterface exif = new ExifInterface(filepath);
float[] latLong = new float[2];
boolean hasLatLong = exif.getLatLong(latLong)
if (hasLatLong) {
System.out.println("Latitude: " + latLong[0]);
System.out.println("Longitude: " + latLong[1]);
}
答案 1 :(得分：0)
ExifInterface exif = new ExifInterface(getContentResolver().openInputStream(selectedImage));
float[] latLong = new float[2];
boolean hasLatLong = exif.getLatLong(latLong)
if (hasLatLong) {
System.out.println("Latitude: " + latLong[0]);
System.out.println("Longitude: " + latLong[1]);
}
请查看此link，以便更好地理解。
另外，最好参考文档here.