按下按钮时如何在文本视图中显示当前位置（LatLng）？
我正在使用GPS跟踪器，但它只会在模拟器中显示当前LatLng，而不会在实际手机上显示。请看一下我的一些代码。
这是我的.jave文件：
import android.annotation.SuppressLint;
import android.app.AlertDialog;
import android.app.Service;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
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;
import java.util.Objects;
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 = 0; // 10 meters
// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 0; // 1 minute
// Declaring a Location Manager
protected LocationManager locationManager;
public GPSTracker(Context context) {
this.mContext = context;
getLocation();
}
@SuppressLint("MissingPermission")
public void getLocation() {
try {
locationManager = (LocationManager) mContext
.getSystemService(LOCATION_SERVICE);
// getting GPS status
isGPSEnabled = Objects.requireNonNull(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;
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();
}
}
/**
* 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 intent) {
return null;
}
}
这就是我的使用方式。
case R.id.btn_service_get_current:
gps = new GPSTracker(getActivity());
if(gps.canGetLocation()){
double lat = gps.getLatitude();
double lng = gps.getLongitude();
@SuppressLint("DefaultLocale") String latit = String.format("%.4f",lat);
@SuppressLint("DefaultLocale") String longit= String.format("%.4f",lng);
lati.setText(latit);
longi.setText(longit);
}else{
AlertDialog alertDialog = new AlertDialog.Builder(getActivity()).create();
alertDialog.setTitle("Notice!");
alertDialog.setMessage("Cannot get your current location, please turn on your device location");
alertDialog.show();
}
break;
如果需要更多代码，请告诉我。
答案 0 :(得分：1)
对于运行时permissions，在以下方法的onCreate()调用的Activity中
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
checkRunTimePermission();
}
private void checkRunTimePermission() {
String[] permissionArrays = new String[]{Manifest.permission.ACCESS_NETWORK_STATE, Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION};
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
requestPermissions(permissionArrays, 11111);
} else {
// if already permition granted
// PUT YOUR ACTION (Like Open cemara etc..)
}
}
检查权限是否已授予override中的Activity
@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
boolean openActivityOnce = true;
boolean openDialogOnce = true;
if (requestCode == 11111) {
for (int i = 0; i < grantResults.length; i++) {
String permission = permissions[i];
boolean isPermitted = grantResults[i] == PackageManager.PERMISSION_GRANTED;
if (grantResults[i] == PackageManager.PERMISSION_DENIED) {
// user rejected the permission
boolean showRationale = false;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
showRationale = shouldShowRequestPermissionRationale(permission);
}
if (!showRationale) {
//execute when 'never Ask Again' tick and permission dialog not show
} else {
}
}
}
}
}