Come spostare direttamente la telecamera nella posizione corrente nell'API di Google Maps per Android v2?

Question

Senza fare clic su alcun pulsante, come ottenere direttamente la posizione corrente e spostare la telecamera su di essa.
Inoltre, ho trovato che c'è un pulsante nella parte superiore destra della mappa. Quando si fa clic su di esso, andrà alla posizione corrente. Come ottenere la posizione in cui ritorna quando si fa clic su quel pulsante?

Answer 1

assicuratevi di avere queste autorizzazioni:

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

poi fare qualche attività e registrare un LocationListener

package com.example.location; 

import android.content.Context; 
import android.location.Location; 
import android.location.LocationListener; 
import android.location.LocationManager; 
import android.os.Bundle; 
import android.view.View; 
import com.actionbarsherlock.app.SherlockFragmentActivity; 
import com.google.android.gms.maps.CameraUpdate; 
import com.google.android.gms.maps.CameraUpdateFactory; 
import com.google.android.gms.maps.GoogleMap; 
import com.google.android.gms.maps.SupportMapFragment; 
import com.google.android.gms.maps.model.LatLng; 

public class LocationActivity extends SherlockFragmentActivity implements LocationListener  { 
private GoogleMap map; 
private LocationManager locationManager; 
private static final long MIN_TIME = 400; 
private static final float MIN_DISTANCE = 1000; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.map); 
    map = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map)).getMap(); 

    locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE); 
    locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, MIN_TIME, MIN_DISTANCE, this); //You can also use LocationManager.GPS_PROVIDER and LocationManager.PASSIVE_PROVIDER   
} 

@Override 
public void onLocationChanged(Location location) { 
    LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude()); 
    CameraUpdate cameraUpdate = CameraUpdateFactory.newLatLngZoom(latLng, 10); 
    map.animateCamera(cameraUpdate); 
    locationManager.removeUpdates(this); 
} 

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

@Override 
public void onProviderEnabled(String provider) { } 

@Override 
public void onProviderDisabled(String provider) { } 
} 

map.xml

<?xml version="1.0" encoding="utf-8"?> 
<fragment xmlns:android="http://schemas.android.com/apk/res/android" 
android:id="@+id/map" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
class="com.google.android.gms.maps.SupportMapFragment"/> 

Answer 2

La risposta di cui sopra non è secondo cosa viene indicato da Google per il rilevamento della posizione in Google API v2.

Ho appena seguito il tutorial ufficiale e ho finito con questa classe che sta recuperando la posizione corrente e centrando la mappa su di essa non appena ho capito.

è possibile estendere questa classe per avere LocationReciever per disporre di un aggiornamento periodico della posizione. Ho appena eseguito questo codice a livello di API 7

http://developer.android.com/training/location/retrieve-current.html

Qui si va.

import android.app.Activity; 
import android.app.Dialog; 
import android.content.Intent; 
import android.content.IntentSender; 
import android.location.Location; 
import android.os.Bundle; 
import android.support.v4.app.DialogFragment; 
import android.support.v4.app.FragmentActivity; 
import android.util.Log; 
import android.widget.Toast; 

import com.google.android.gms.common.ConnectionResult; 
import com.google.android.gms.common.GooglePlayServicesClient; 
import com.google.android.gms.common.GooglePlayServicesUtil; 
import com.google.android.gms.location.LocationClient; 
import com.google.android.gms.maps.CameraUpdate; 
import com.google.android.gms.maps.CameraUpdateFactory; 
import com.google.android.gms.maps.GoogleMap; 
import com.google.android.gms.maps.GoogleMap.OnMapLongClickListener; 
import com.google.android.gms.maps.SupportMapFragment; 
import com.google.android.gms.maps.model.LatLng; 


public class MainActivity extends FragmentActivity implements 
    GooglePlayServicesClient.ConnectionCallbacks, 
    GooglePlayServicesClient.OnConnectionFailedListener{ 

private SupportMapFragment mapFragment; 
private GoogleMap map; 
private LocationClient mLocationClient; 
/* 
* Define a request code to send to Google Play services 
* This code is returned in Activity.onActivityResult 
*/ 
private final static int CONNECTION_FAILURE_RESOLUTION_REQUEST = 9000; 

// Define a DialogFragment that displays the error dialog 
public static class ErrorDialogFragment extends DialogFragment { 

    // Global field to contain the error dialog 
    private Dialog mDialog; 

    // Default constructor. Sets the dialog field to null 
    public ErrorDialogFragment() { 
     super(); 
     mDialog = null; 
    } 

    // Set the dialog to display 
    public void setDialog(Dialog dialog) { 
     mDialog = dialog; 
    } 

    // Return a Dialog to the DialogFragment. 
    @Override 
    public Dialog onCreateDialog(Bundle savedInstanceState) { 
     return mDialog; 
    } 
} 

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

    mLocationClient = new LocationClient(this, this, this); 

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

    map.setMyLocationEnabled(true); 

} 

/* 
* Called when the Activity becomes visible. 
*/ 
@Override 
protected void onStart() { 
    super.onStart(); 
    // Connect the client. 
    if(isGooglePlayServicesAvailable()){ 
     mLocationClient.connect(); 
    } 

} 

/* 
* Called when the Activity is no longer visible. 
*/ 
@Override 
protected void onStop() { 
    // Disconnecting the client invalidates it. 
    mLocationClient.disconnect(); 
    super.onStop(); 
} 

/* 
* Handle results returned to the FragmentActivity 
* by Google Play services 
*/ 
@Override 
protected void onActivityResult(
       int requestCode, int resultCode, Intent data) { 
    // Decide what to do based on the original request code 
    switch (requestCode) { 

     case CONNECTION_FAILURE_RESOLUTION_REQUEST: 
      /* 
      * If the result code is Activity.RESULT_OK, try 
      * to connect again 
      */ 
      switch (resultCode) { 
       case Activity.RESULT_OK: 
        mLocationClient.connect(); 
        break; 
      } 

    } 
} 

private boolean isGooglePlayServicesAvailable() { 
    // Check that Google Play services is available 
    int resultCode = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this); 
    // If Google Play services is available 
    if (ConnectionResult.SUCCESS == resultCode) { 
     // In debug mode, log the status 
     Log.d("Location Updates", "Google Play services is available."); 
     return true; 
    } else { 
     // Get the error dialog from Google Play services 
     Dialog errorDialog = GooglePlayServicesUtil.getErrorDialog(resultCode, 
                               this, 
                               CONNECTION_FAILURE_RESOLUTION_REQUEST); 

     // If Google Play services can provide an error dialog 
     if (errorDialog != null) { 
      // Create a new DialogFragment for the error dialog 
      ErrorDialogFragment errorFragment = new ErrorDialogFragment(); 
      errorFragment.setDialog(errorDialog); 
      errorFragment.show(getSupportFragmentManager(), "Location Updates"); 
     } 

     return false; 
    } 
} 

/* 
* Called by Location Services when the request to connect the 
* client finishes successfully. At this point, you can 
* request the current location or start periodic updates 
*/ 
@Override 
public void onConnected(Bundle dataBundle) { 
    // Display the connection status 
    Toast.makeText(this, "Connected", Toast.LENGTH_SHORT).show(); 
    Location location = mLocationClient.getLastLocation(); 
    LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude()); 
    CameraUpdate cameraUpdate = CameraUpdateFactory.newLatLngZoom(latLng, 17); 
    map.animateCamera(cameraUpdate); 
} 

/* 
* Called by Location Services if the connection to the 
* location client drops because of an error. 
*/ 
@Override 
public void onDisconnected() { 
    // Display the connection status 
    Toast.makeText(this, "Disconnected. Please re-connect.", 
      Toast.LENGTH_SHORT).show(); 
} 

/* 
* Called by Location Services if the attempt to 
* Location Services fails. 
*/ 
@Override 
public void onConnectionFailed(ConnectionResult connectionResult) { 
    /* 
    * Google Play services can resolve some errors it detects. 
    * If the error has a resolution, try sending an Intent to 
    * start a Google Play services activity that can resolve 
    * error. 
    */ 
    if (connectionResult.hasResolution()) { 
     try { 
      // Start an Activity that tries to resolve the error 
      connectionResult.startResolutionForResult(
        this, 
        CONNECTION_FAILURE_RESOLUTION_REQUEST); 
      /* 
      * Thrown if Google Play services canceled the original 
      * PendingIntent 
      */ 
     } catch (IntentSender.SendIntentException e) { 
      // Log the error 
      e.printStackTrace(); 
     } 
    } else { 
     Toast.makeText(getApplicationContext(), "Sorry. Location services not available to you", Toast.LENGTH_LONG).show(); 
    } 
} 

} 

Answer 3

Sto spiegando come ottenere la posizione corrente e spostare direttamente la telecamera nella posizione corrente presumendo di aver implementato map-v2. Per maggiori dettagli, è possibile consultare official doc.

Aggiungi il servizio di localizzazione in Gradle

implementation "com.google.android.gms:play-services-location:11.0.1" 

Aggiungere posizione autorizzazione file manifesto

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

assicuratevi di chiedere per RuntimePermission. Sto usando Ask-Permission per quello. È facile da usare.

Ora fare riferimento al codice seguente per ottenere la posizione corrente e visualizzarla su una mappa.

private FusedLocationProviderClient mFusedLocationProviderClient; 

@Override 
public void onCreate(@Nullable Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     mFusedLocationProviderClient = LocationServices 
       .getFusedLocationProviderClient(getActivity()); 

} 

private void getDeviceLocation() { 
     try { 
      if (mLocationPermissionGranted) { 
       Task<Location> locationResult = mFusedLocationProviderClient.getLastLocation(); 
       locationResult.addOnCompleteListener(new OnCompleteListener<Location>() { 
        @Override 
        public void onComplete(@NonNull Task<Location> task) { 
         if (task.isSuccessful()) { 
          // Set the map's camera position to the current location of the device. 
          Location location = task.getResult(); 
          LatLng currentLatLng = new LatLng(location.getLatitude(), 
            location.getLongitude()); 
          CameraUpdate update = CameraUpdateFactory.newLatLngZoom(currentLatLng, 
            DEFAULT_ZOOM); 
          googleMap.moveCamera(update); 
         } 
        } 
       }); 
      } 
     } catch (SecurityException e) { 
      Log.e("Exception: %s", e.getMessage()); 
     } 
} 

Quando l'utente ha concesso il permesso luogo di chiamata sopra getDeviceLocation() metodo

private void updateLocationUI() { 
     if (googleMap == null) { 
      return; 
     } 
     try { 
      if (mLocationPermissionGranted) { 
       googleMap.setMyLocationEnabled(true); 
       googleMap.getUiSettings().setMyLocationButtonEnabled(true); 
       getDeviceLocation(); 
      } else { 
       googleMap.setMyLocationEnabled(false); 
       googleMap.getUiSettings().setMyLocationButtonEnabled(false); 
      } 
     } catch (SecurityException e) { 
      Log.e("Exception: %s", e.getMessage()); 
     } 
    }