Dowiedz się, jak znaleźć bieżącą lokalizację urządzenia z Androidem i wyświetlić szczegóły miejsca (firmy lub innego ważnego miejsca) w tej lokalizacji. Z tego samouczka dowiesz się, jak utworzyć aplikację na Androida za pomocą Maps SDK na Androida, pakietu SDK Miejsc na Androida i dostawcy uśrednionej lokalizacji w interfejsach API lokalizacji Usług Google Play.
Pobierz kod
Sklonuj lub pobierz repozytorium przykładów Google Maps Android API v2 z GitHuba.
Wyświetl wersję aktywności w języku Java:
// Copyright 2020 Google LLC // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. package com.example.currentplacedetailsonmap; import android.content.DialogInterface; import android.content.pm.PackageManager; import android.location.Location; import android.os.Bundle; import android.util.Log; import android.util.TypedValue; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.widget.FrameLayout; import android.widget.TextView; import android.widget.Toast; import androidx.annotation.NonNull; import androidx.appcompat.app.AlertDialog; import androidx.appcompat.app.AppCompatActivity; import androidx.core.app.ActivityCompat; import androidx.core.content.ContextCompat; import androidx.core.graphics.Insets; import androidx.core.view.ViewCompat; import androidx.core.view.WindowInsetsCompat; import com.google.android.gms.location.FusedLocationProviderClient; import com.google.android.gms.location.LocationServices; 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.CameraPosition; 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 com.google.android.gms.tasks.OnCompleteListener; import com.google.android.gms.tasks.Task; import com.google.android.libraries.places.api.Places; import com.google.android.libraries.places.api.model.CircularBounds; import com.google.android.libraries.places.api.model.Place; import com.google.android.libraries.places.api.net.PlacesClient; import com.google.android.libraries.places.api.net.SearchNearbyRequest; import com.google.android.libraries.places.api.net.SearchNearbyResponse; import java.util.ArrayList; import java.util.Arrays; import java.util.List; /** An activity that displays a map showing the place at the device's current location. */ public class MapsActivityCurrentPlace extends AppCompatActivity implements OnMapReadyCallback { private static final String TAG = MapsActivityCurrentPlace.class.getSimpleName(); private GoogleMap map; private CameraPosition cameraPosition; // The entry point to the Places API. private PlacesClient placesClient; // The entry point to the Fused Location Provider. private FusedLocationProviderClient fusedLocationProviderClient; // A default location (Sydney, Australia) and default zoom to use when location permission is // not granted. private final LatLng defaultLocation = new LatLng(-33.8523341, 151.2106085); private static final int DEFAULT_ZOOM = 15; private static final int PERMISSIONS_REQUEST_ACCESS_FINE_LOCATION = 1; private boolean locationPermissionGranted; // The geographical location where the device is currently located. That is, the last-known // location retrieved by the Fused Location Provider or set via long press. Location lastKnownLocation; // Keys for storing activity state. private static final String KEY_CAMERA_POSITION = "camera_position"; private static final String KEY_LOCATION = "location"; // Used for selecting the current place. private static final int M_MAX_ENTRIES = 5; private static final double SEARCH_RADIUS_METERS = 100.0; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); // Retrieve location and camera position from saved instance state. if (savedInstanceState != null) { lastKnownLocation = savedInstanceState.getParcelable(KEY_LOCATION); cameraPosition = savedInstanceState.getParcelable(KEY_CAMERA_POSITION); } // Retrieve the content view that renders the map. setContentView(R.layout.activity_maps); ViewCompat.setOnApplyWindowInsetsListener( getWindow().getDecorView(), (v, insets) -> { Insets systemBars = insets.getInsets( WindowInsetsCompat.Type.systemBars() | WindowInsetsCompat.Type.displayCutout()); View actionBarContainer = getWindow() .getDecorView() .findViewById(androidx.appcompat.R.id.action_bar_container); if (actionBarContainer != null) { actionBarContainer.setPadding( actionBarContainer.getPaddingLeft(), systemBars.top, actionBarContainer.getPaddingRight(), actionBarContainer.getPaddingBottom()); } TypedValue typedValue = new TypedValue(); int actionBarHeight = getTheme() .resolveAttribute( android.R.attr.actionBarSize, typedValue, true) ? TypedValue.complexToDimensionPixelSize( typedValue.data, getResources().getDisplayMetrics()) : 0; if (map != null) { map.setPadding(0, systemBars.top + actionBarHeight, 0, systemBars.bottom); } return insets; }); // Construct a PlacesClient Places.initializeWithNewPlacesApiEnabled(getApplicationContext(), BuildConfig.MAPS_API_KEY); placesClient = Places.createClient(this); // Construct a FusedLocationProviderClient. fusedLocationProviderClient = LocationServices.getFusedLocationProviderClient(this); // Build the map. SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map); mapFragment.getMapAsync(this); } /** Saves the state of the map when the activity is paused. */ @Override protected void onSaveInstanceState(Bundle outState) { if (map != null) { outState.putParcelable(KEY_CAMERA_POSITION, map.getCameraPosition()); outState.putParcelable(KEY_LOCATION, lastKnownLocation); } super.onSaveInstanceState(outState); } /** * Sets up the options menu. * * @param menu The options menu. * @return Boolean. */ @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.current_place_menu, menu); return true; } /** * Handles a click on the menu option to get a place. * * @param item The menu item to handle. * @return Boolean. */ @Override public boolean onOptionsItemSelected(MenuItem item) { if (item.getItemId() == R.id.option_get_place) { showCurrentPlace(); } return true; } /** * Manipulates the map when it's available. This callback is triggered when the map is ready to * be used. */ @Override public void onMapReady(GoogleMap map) { this.map = map; // Use a custom info window adapter to handle multiple lines of text in the // info window contents. this.map.setInfoWindowAdapter( new GoogleMap.InfoWindowAdapter() { @Override // Return null here, so that getInfoContents() is called next. public View getInfoWindow(Marker arg0) { return null; } @Override public View getInfoContents(Marker marker) { // Inflate the layouts for the info window, title and snippet. View infoWindow = getLayoutInflater() .inflate( R.layout.custom_info_contents, (FrameLayout) findViewById(R.id.map), false); TextView title = infoWindow.findViewById(R.id.title); title.setText(marker.getTitle()); TextView snippet = infoWindow.findViewById(R.id.snippet); snippet.setText(marker.getSnippet()); return infoWindow; } }); // Allow moving the current location with a long press on the map to easily // demo and discover nearby places anywhere in the world. this.map.setOnMapLongClickListener(this::setCustomLocation); // Prompt the user for permission. getLocationPermission(); WindowInsetsCompat rootInsets = ViewCompat.getRootWindowInsets(getWindow().getDecorView()); if (rootInsets != null) { Insets systemBars = rootInsets.getInsets( WindowInsetsCompat.Type.systemBars() | WindowInsetsCompat.Type.displayCutout()); TypedValue typedValue = new TypedValue(); int actionBarHeight = getTheme().resolveAttribute(android.R.attr.actionBarSize, typedValue, true) ? TypedValue.complexToDimensionPixelSize( typedValue.data, getResources().getDisplayMetrics()) : 0; this.map.setPadding(0, systemBars.top + actionBarHeight, 0, systemBars.bottom); } // Turn on the My Location layer and the related control on the map. updateLocationUI(); // Get the current location of the device and set the position of the map. getDeviceLocation(); } /** Gets the current location of the device, and positions the map's camera. */ private void getDeviceLocation() { /* * Get the best and most recent location of the device, which may be null in rare * cases when a location is not available. */ try { if (locationPermissionGranted) { Task<Location> locationResult = fusedLocationProviderClient.getLastLocation(); locationResult.addOnCompleteListener( this, 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. lastKnownLocation = task.getResult(); if (lastKnownLocation != null) { map.moveCamera( CameraUpdateFactory.newLatLngZoom( new LatLng( lastKnownLocation.getLatitude(), lastKnownLocation.getLongitude()), DEFAULT_ZOOM)); } } else { Log.d(TAG, "Current location is null. Using defaults."); Log.e(TAG, "Exception: %s", task.getException()); map.moveCamera( CameraUpdateFactory.newLatLngZoom( defaultLocation, DEFAULT_ZOOM)); map.getUiSettings().setMyLocationButtonEnabled(false); } } }); } } catch (SecurityException e) { Log.e("Exception: %s", e.getMessage(), e); } } /** Prompts the user for permission to use the device location. */ private void getLocationPermission() { /* * Request location permission, so that we can get the location of the * device. The result of the permission request is handled by a callback, * onRequestPermissionsResult. */ if (ContextCompat.checkSelfPermission( this.getApplicationContext(), android.Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) { locationPermissionGranted = true; } else { ActivityCompat.requestPermissions( this, new String[] {android.Manifest.permission.ACCESS_FINE_LOCATION}, PERMISSIONS_REQUEST_ACCESS_FINE_LOCATION); } } /** Handles the result of the request for location permissions. */ @Override public void onRequestPermissionsResult( int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) { locationPermissionGranted = false; if (requestCode == PERMISSIONS_REQUEST_ACCESS_FINE_LOCATION) { // If request is cancelled, the // result arrays are empty. if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) { locationPermissionGranted = true; } } else { super.onRequestPermissionsResult(requestCode, permissions, grantResults); } updateLocationUI(); } /** * UI representation of a place item to display in the selection dialog and map marker. * * <p>It is good practice to decouple the external data/backend model ({@link Place}) from the * UI layer. The UI should be as free of logic as possible: it receives presentation-ready data * (non-null coordinates, ready-to-display title and snippet strings) so that dialogs and map * overlays remain simple, predictable, and testable. */ static class PlaceItemUiModel { final String title; final String snippet; final LatLng position; PlaceItemUiModel(String title, String snippet, LatLng position) { this.title = title; this.snippet = snippet; this.position = position; } } /** * Maps an external {@link Place} domain model into a display-ready {@link PlaceItemUiModel}. * * <p>The mapper encapsulates all data normalization, default value fallbacks (such as fallback * titles), and string formatting (such as appending third-party attributions to the address). * Keeping this transformation logic in the mapper prevents business and formatting logic from * leaking into the UI components. Returns {@code null} if essential coordinates are missing. */ private PlaceItemUiModel toUiModel(Place place) { return toUiModel(place, getString(R.string.default_info_title)); } static PlaceItemUiModel toUiModel(Place place, String defaultTitle) { if (place.getLocation() == null) { return null; } String title = place.getDisplayName() != null ? place.getDisplayName() : defaultTitle; StringBuilder snippet = new StringBuilder(); if (place.getFormattedAddress() != null) { snippet.append(place.getFormattedAddress()); } if (place.getAttributions() != null && !place.getAttributions().isEmpty()) { if (snippet.length() > 0) { snippet.append("\n"); } snippet.append(String.join("\n", place.getAttributions())); } return new PlaceItemUiModel(title, snippet.toString(), place.getLocation()); } /** * Prompts the user to select the current place from a list of likely places, and shows the * current place on the map - provided the user has granted location permission. */ private void showCurrentPlace() { if (map == null) { return; } if (lastKnownLocation != null && "manual".equals(lastKnownLocation.getProvider())) { locationPermissionGranted = true; } if (locationPermissionGranted) { // Use fields to define the data types to return. List<Place.Field> placeFields = Arrays.asList( Place.Field.DISPLAY_NAME, Place.Field.FORMATTED_ADDRESS, Place.Field.LOCATION); // Search around the device's last-known location, falling back to the center of the // map if the location is not available yet. LatLng center = lastKnownLocation != null ? new LatLng( lastKnownLocation.getLatitude(), lastKnownLocation.getLongitude()) : map.getCameraPosition().target; CircularBounds searchArea = CircularBounds.newInstance(center, SEARCH_RADIUS_METERS); // Use the builder to create a SearchNearbyRequest that returns the closest places // first. SearchNearbyRequest request = SearchNearbyRequest.builder(searchArea, placeFields) .setMaxResultCount(M_MAX_ENTRIES) .setRankPreference(SearchNearbyRequest.RankPreference.DISTANCE) .build(); // Get the likely places - that is, the businesses and other points of interest that // are closest to the device's current location. final Task<SearchNearbyResponse> placeResult = placesClient.searchNearby(request); placeResult.addOnCompleteListener( new OnCompleteListener<SearchNearbyResponse>() { @Override public void onComplete(@NonNull Task<SearchNearbyResponse> task) { if (task.isSuccessful() && task.getResult() != null) { List<Place> responsePlaces = task.getResult().getPlaces(); int count = Math.min(responsePlaces.size(), M_MAX_ENTRIES); List<PlaceItemUiModel> likelyPlaces = new ArrayList<>(); for (int i = 0; i < count; i++) { PlaceItemUiModel model = toUiModel(responsePlaces.get(i)); if (model != null) { likelyPlaces.add(model); } } // Show a dialog offering the user the list of likely places, and // add a marker at the selected place. MapsActivityCurrentPlace.this.openPlacesDialog(likelyPlaces); } else { Log.e(TAG, "Exception: %s", task.getException()); } } }); } else { // The user has not granted permission. Log.i(TAG, "The user did not grant location permission."); // Add a default marker, because the user hasn't selected a place. map.addMarker( new MarkerOptions() .title(getString(R.string.default_info_title)) .position(defaultLocation) .snippet(getString(R.string.default_info_snippet))); // Prompt the user for permission. getLocationPermission(); } } /** Displays a form allowing the user to select a place from a list of likely places. */ void openPlacesDialog(List<PlaceItemUiModel> likelyPlaces) { if (likelyPlaces.isEmpty()) { Toast.makeText( this, "No places found nearby. Long-press on the map to choose another location.", Toast.LENGTH_LONG) .show(); return; } // Ask the user to choose the place where they are now. DialogInterface.OnClickListener listener = new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { // The "which" argument contains the position of the selected item. PlaceItemUiModel selectedPlace = likelyPlaces.get(which); // Add a marker for the selected place, with an info window // showing information about that place. map.addMarker( new MarkerOptions() .title(selectedPlace.title) .position(selectedPlace.position) .snippet(selectedPlace.snippet)); // Position the map's camera at the location of the marker. map.moveCamera( CameraUpdateFactory.newLatLngZoom( selectedPlace.position, DEFAULT_ZOOM)); } }; // Display the dialog. String[] titles = new String[likelyPlaces.size()]; for (int i = 0; i < likelyPlaces.size(); i++) { titles[i] = likelyPlaces.get(i).title; } new AlertDialog.Builder(this) .setTitle(R.string.pick_place) .setItems(titles, listener) .show(); } /** Updates the map's UI settings based on whether the user has granted location permission. */ private void updateLocationUI() { if (map == null) { return; } try { if (locationPermissionGranted) { map.setMyLocationEnabled(true); map.getUiSettings().setMyLocationButtonEnabled(true); } else { map.setMyLocationEnabled(false); map.getUiSettings().setMyLocationButtonEnabled(false); lastKnownLocation = null; } } catch (SecurityException e) { Log.e("Exception: %s", e.getMessage()); } } /** Updates the current location and searches for places around the specified coordinate. */ void setCustomLocation(LatLng latLng) { Location location = new Location("manual"); location.setLatitude(latLng.latitude); location.setLongitude(latLng.longitude); lastKnownLocation = location; if (map != null) { map.animateCamera(CameraUpdateFactory.newLatLng(latLng)); } showCurrentPlace(); } }
Wyświetl wersję aktywności w języku Kotlin:
// Copyright 2020 Google LLC // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. package com.example.currentplacedetailsonmap import android.Manifest import android.annotation.SuppressLint import android.content.DialogInterface import android.content.pm.PackageManager import android.location.Location import android.os.Bundle import android.util.Log import android.util.TypedValue import android.view.Menu import android.view.MenuItem import android.view.View import android.widget.FrameLayout import android.widget.TextView import android.widget.Toast import androidx.appcompat.app.AlertDialog import androidx.appcompat.app.AppCompatActivity import androidx.core.app.ActivityCompat import androidx.core.content.ContextCompat import androidx.core.view.ViewCompat import androidx.core.view.WindowInsetsCompat import com.google.android.gms.location.FusedLocationProviderClient import com.google.android.gms.location.LocationServices import com.google.android.gms.maps.CameraUpdateFactory import com.google.android.gms.maps.GoogleMap import com.google.android.gms.maps.GoogleMap.InfoWindowAdapter import com.google.android.gms.maps.OnMapReadyCallback import com.google.android.gms.maps.SupportMapFragment import com.google.android.gms.maps.model.CameraPosition 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 com.google.android.libraries.places.api.Places import com.google.android.libraries.places.api.model.CircularBounds import com.google.android.libraries.places.api.model.Place import com.google.android.libraries.places.api.net.PlacesClient import com.google.android.libraries.places.api.net.SearchNearbyRequest /** * An activity that displays a map showing the place at the device's current location. */ class MapsActivityCurrentPlace : AppCompatActivity(), OnMapReadyCallback { private var map: GoogleMap? = null private var cameraPosition: CameraPosition? = null internal var selectedMarker: Marker? = null // The entry point to the Places API. private lateinit var placesClient: PlacesClient // The entry point to the Fused Location Provider. private lateinit var fusedLocationProviderClient: FusedLocationProviderClient // A default location (Sydney, Australia) and default zoom to use when location permission is // not granted. private val defaultLocation = LatLng(-33.8523341, 151.2106085) private var locationPermissionGranted = false // The geographical location where the device is currently located. That is, the last-known // location retrieved by the Fused Location Provider or set via long press. internal var lastKnownLocation: Location? = null override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) // Retrieve location and camera position from saved instance state. if (savedInstanceState != null) { lastKnownLocation = savedInstanceState.getParcelable(KEY_LOCATION) cameraPosition = savedInstanceState.getParcelable(KEY_CAMERA_POSITION) } // Retrieve the content view that renders the map. setContentView(R.layout.activity_maps) ViewCompat.setOnApplyWindowInsetsListener(window.decorView) { _, insets -> val systemBars = insets.getInsets( WindowInsetsCompat.Type.systemBars() or WindowInsetsCompat.Type.displayCutout(), ) val actionBarContainer = window.decorView.findViewById<View>(androidx.appcompat.R.id.action_bar_container) actionBarContainer?.setPadding( actionBarContainer.paddingLeft, systemBars.top, actionBarContainer.paddingRight, actionBarContainer.paddingBottom, ) val typedValue = TypedValue() val actionBarHeight = if (theme.resolveAttribute(android.R.attr.actionBarSize, typedValue, true)) { TypedValue.complexToDimensionPixelSize(typedValue.data, resources.displayMetrics) } else { 0 } map?.setPadding(0, systemBars.top + actionBarHeight, 0, systemBars.bottom) insets } // Construct a PlacesClient Places.initializeWithNewPlacesApiEnabled(applicationContext, BuildConfig.MAPS_API_KEY) placesClient = Places.createClient(this) // Construct a FusedLocationProviderClient. fusedLocationProviderClient = LocationServices.getFusedLocationProviderClient(this) // Build the map. val mapFragment = supportFragmentManager .findFragmentById(R.id.map) as SupportMapFragment? mapFragment?.getMapAsync(this) } /** * Saves the state of the map when the activity is paused. */ override fun onSaveInstanceState(outState: Bundle) { map?.let { map -> outState.putParcelable(KEY_CAMERA_POSITION, map.cameraPosition) outState.putParcelable(KEY_LOCATION, lastKnownLocation) } super.onSaveInstanceState(outState) } /** * Sets up the options menu. * @param menu The options menu. * @return Boolean. */ override fun onCreateOptionsMenu(menu: Menu): Boolean { menuInflater.inflate(R.menu.current_place_menu, menu) return true } /** * Handles a click on the menu option to get a place. * @param item The menu item to handle. * @return Boolean. */ override fun onOptionsItemSelected(item: MenuItem): Boolean { if (item.itemId == R.id.option_get_place) { showCurrentPlace() } return true } /** * Manipulates the map when it's available. * This callback is triggered when the map is ready to be used. */ override fun onMapReady(map: GoogleMap) { this.map = map // Use a custom info window adapter to handle multiple lines of text in the // info window contents. this.map?.setInfoWindowAdapter(object : InfoWindowAdapter { // Return null here, so that getInfoContents() is called next. override fun getInfoWindow(arg0: Marker): View? = null override fun getInfoContents(marker: Marker): View { // Inflate the layouts for the info window, title and snippet. val infoWindow = layoutInflater.inflate( R.layout.custom_info_contents, findViewById<FrameLayout>(R.id.map), false, ) val title = infoWindow.findViewById<TextView>(R.id.title) title.text = marker.title val snippet = infoWindow.findViewById<TextView>(R.id.snippet) snippet.text = marker.snippet return infoWindow } }) // Allow moving the current location with a long press on the map to easily // demo and discover nearby places anywhere in the world. this.map?.setOnMapLongClickListener { latLng -> setCustomLocation(latLng) } // Prompt the user for permission. getLocationPermission() val insets = ViewCompat.getRootWindowInsets(window.decorView) ?.getInsets(WindowInsetsCompat.Type.systemBars() or WindowInsetsCompat.Type.displayCutout()) val topInset = insets?.top ?: 0 val bottomInset = insets?.bottom ?: 0 val typedValue = TypedValue() val actionBarHeight = if (theme.resolveAttribute(android.R.attr.actionBarSize, typedValue, true)) { TypedValue.complexToDimensionPixelSize(typedValue.data, resources.displayMetrics) } else { 0 } this.map?.setPadding(0, topInset + actionBarHeight, 0, bottomInset) // Turn on the My Location layer and the related control on the map. updateLocationUI() // Get the current location of the device and set the position of the map. getDeviceLocation() } /** * Gets the current location of the device, and positions the map's camera. */ @SuppressLint("MissingPermission") private fun getDeviceLocation() { /* * Get the best and most recent location of the device, which may be null in rare * cases when a location is not available. */ try { if (locationPermissionGranted) { val locationResult = fusedLocationProviderClient.lastLocation locationResult.addOnCompleteListener(this) { task -> if (task.isSuccessful) { // Set the map's camera position to the current location of the device. lastKnownLocation = task.result if (lastKnownLocation != null) { map?.moveCamera( CameraUpdateFactory.newLatLngZoom( LatLng( lastKnownLocation!!.latitude, lastKnownLocation!!.longitude, ), DEFAULT_ZOOM.toFloat(), ), ) } } else { Log.d(TAG, "Current location is null. Using defaults.") Log.e(TAG, "Exception: %s", task.exception) map?.moveCamera( CameraUpdateFactory .newLatLngZoom(defaultLocation, DEFAULT_ZOOM.toFloat()), ) map?.uiSettings?.isMyLocationButtonEnabled = false } } } } catch (e: SecurityException) { Log.e("Exception: %s", e.message, e) } } /** * Prompts the user for permission to use the device location. */ private fun getLocationPermission() { /* * Request location permission, so that we can get the location of the * device. The result of the permission request is handled by a callback, * onRequestPermissionsResult. */ if (ContextCompat.checkSelfPermission( this.applicationContext, Manifest.permission.ACCESS_FINE_LOCATION, ) == PackageManager.PERMISSION_GRANTED ) { locationPermissionGranted = true } else { ActivityCompat.requestPermissions( this, arrayOf(Manifest.permission.ACCESS_FINE_LOCATION), PERMISSIONS_REQUEST_ACCESS_FINE_LOCATION, ) } } /** * Handles the result of the request for location permissions. */ override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<String>, grantResults: IntArray) { locationPermissionGranted = false when (requestCode) { PERMISSIONS_REQUEST_ACCESS_FINE_LOCATION -> { // If request is cancelled, the result arrays are empty. if (grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED ) { locationPermissionGranted = true } } else -> super.onRequestPermissionsResult(requestCode, permissions, grantResults) } updateLocationUI() } private fun Place.toUiModel(): PlaceItemUiModel? = toPlaceItemUiModel(this, getString(R.string.default_info_title)) /** * Prompts the user to select the current place from a list of likely places, and shows the * current place on the map - provided the user has granted location permission. */ private fun showCurrentPlace() { val map = map ?: return if (lastKnownLocation?.provider == "manual") { locationPermissionGranted = true } if (locationPermissionGranted) { // Use fields to define the data types to return. val placeFields = listOf( Place.Field.DISPLAY_NAME, Place.Field.FORMATTED_ADDRESS, Place.Field.LOCATION, ) // Search around the device's last-known location, falling back to the center of // the map if the location is not available yet. val center = lastKnownLocation?.let { LatLng(it.latitude, it.longitude) } ?: map.cameraPosition.target val searchArea = CircularBounds.newInstance(center, SEARCH_RADIUS_METERS) // Use the builder to create a SearchNearbyRequest that returns the closest places // first. val request = SearchNearbyRequest.builder(searchArea, placeFields) .setMaxResultCount(M_MAX_ENTRIES) .setRankPreference(SearchNearbyRequest.RankPreference.DISTANCE) .build() // Get the likely places - that is, the businesses and other points of interest that // are closest to the device's current location. val placeResult = placesClient.searchNearby(request) placeResult.addOnCompleteListener { task -> if (task.isSuccessful && task.result != null) { val likelyPlaces = task.result.places .take(M_MAX_ENTRIES) .mapNotNull { it.toUiModel() } // Show a dialog offering the user the list of likely places, and add a // marker at the selected place. openPlacesDialog(likelyPlaces) } else { Log.e(TAG, "Exception: %s", task.exception) } } } else { // The user has not granted permission. Log.i(TAG, "The user did not grant location permission.") // Add a default marker, because the user hasn't selected a place. map.addMarker( MarkerOptions() .title(getString(R.string.default_info_title)) .position(defaultLocation) .snippet(getString(R.string.default_info_snippet)), ) // Prompt the user for permission. getLocationPermission() } } /** * Displays a form allowing the user to select a place from a list of likely places. */ internal fun openPlacesDialog(likelyPlaces: List<PlaceItemUiModel>) { if (likelyPlaces.isEmpty()) { Toast.makeText( this, "No places found nearby. Long-press on the map to choose another location.", Toast.LENGTH_LONG, ).show() return } // Ask the user to choose the place where they are now. val listener = DialogInterface.OnClickListener { _, which -> // The "which" argument contains the position of the selected item. val selectedPlace = likelyPlaces[which] // Add a marker for the selected place, with an info window // showing information about that place. selectedMarker = map?.addMarker( MarkerOptions() .title(selectedPlace.title) .position(selectedPlace.position) .snippet(selectedPlace.snippet), ) // Position the map's camera at the location of the marker. map?.moveCamera( CameraUpdateFactory.newLatLngZoom( selectedPlace.position, DEFAULT_ZOOM.toFloat(), ), ) } // Display the dialog. val titles = likelyPlaces.map { it.title }.toTypedArray() AlertDialog.Builder(this) .setTitle(R.string.pick_place) .setItems(titles, listener) .show() } /** * Updates the map's UI settings based on whether the user has granted location permission. */ @SuppressLint("MissingPermission") private fun updateLocationUI() { if (map == null) { return } try { if (locationPermissionGranted) { map?.isMyLocationEnabled = true map?.uiSettings?.isMyLocationButtonEnabled = true } else { map?.isMyLocationEnabled = false map?.uiSettings?.isMyLocationButtonEnabled = false lastKnownLocation = null getLocationPermission() } } catch (e: SecurityException) { Log.e("Exception: %s", e.message, e) } } /** * Updates the current location and searches for places around the specified coordinate. */ internal fun setCustomLocation(latLng: LatLng) { val location = Location("manual").apply { latitude = latLng.latitude longitude = latLng.longitude } lastKnownLocation = location map?.animateCamera(CameraUpdateFactory.newLatLng(latLng)) showCurrentPlace() } companion object { private val TAG = MapsActivityCurrentPlace::class.java.simpleName private const val DEFAULT_ZOOM = 15 private const val PERMISSIONS_REQUEST_ACCESS_FINE_LOCATION = 1 // Keys for storing activity state. private const val KEY_CAMERA_POSITION = "camera_position" private const val KEY_LOCATION = "location" // Used for selecting the current place. private const val M_MAX_ENTRIES = 5 private const val SEARCH_RADIUS_METERS = 100.0 } } /** * UI representation of a place item to display in the selection dialog and map marker. * * It is good practice to decouple the external data/backend model ([Place]) from the UI layer. * The UI should be as free of logic as possible: it receives presentation-ready data (non-null * coordinates, ready-to-display title and snippet strings) so that dialogs and map overlays * remain simple, predictable, and testable. */ internal data class PlaceItemUiModel(val title: String, val snippet: String, val position: LatLng) /** * Maps an external [Place] domain model into a display-ready [PlaceItemUiModel]. * * The mapper encapsulates all data normalization, default value fallbacks (such as fallback * titles), and string formatting (such as appending third-party attributions to the address). * Keeping this transformation logic in the mapper prevents business and formatting logic * from leaking into the UI components. Returns `null` if essential coordinates are missing. */ internal fun toPlaceItemUiModel(place: Place, defaultTitle: String): PlaceItemUiModel? { val position = place.location ?: return null val title = place.displayName ?: defaultTitle val snippet = buildString { place.formattedAddress?.let { append(it) } place.attributions?.takeIf { it.isNotEmpty() }?.let { if (isNotEmpty()) append("\n") append(it.joinToString("\n")) } } return PlaceItemUiModel(title = title, snippet = snippet, position = position) }
Konfigurowanie projektu programistycznego
Aby utworzyć projekt samouczka w Android Studio, wykonaj te czynności.
- Pobierz i zainstaluj Android Studio.
- Dodaj pakiet usług Google Play do Android Studio.
- Sklonuj lub pobierz repozytorium przykładów Google Maps Android API v2, jeśli nie zostało to zrobione przed rozpoczęciem czytania tego samouczka.
Zaimportuj projekt samouczka:
- W Android Studio wybierz Plik > Nowy > Importuj projekt.
- Otwórz lokalizację, w której zostało zapisane pobrane repozytorium przykładów Google Maps Android API v2.
- Znajdź projekt CurrentPlaceDetailsOnMap w tej lokalizacji:
PATH-TO-SAVED-REPO/android-samples/tutorials/java/CurrentPlaceDetailsOnMap(Java) lub
PATH-TO-SAVED-REPO/android-samples/tutorials/kotlin/CurrentPlaceDetailsOnMap(Kotlin). - Wybierz katalog projektu, a następnie kliknij Otwórz. Android Studio utworzy teraz projekt za pomocą narzędzia do kompilacji Gradle.
Włączanie niezbędnych interfejsów API i uzyskiwanie klucza interfejsu API
Aby móc wykonać zadania z tego samouczka, musisz mieć projekt Google Cloud z włączonymi niezbędnymi interfejsami API oraz klucz interfejsu API, który jest autoryzowany do korzystania z pakietu Maps SDK for Android. Więcej informacji:
Aby wyświetlić włączone interfejsy API, otwórz stronę Google Maps Platform w konsoli Cloud i wybierz projekt:
Otwórz stronę Google Maps PlatformJeśli nie widzisz, że interfejs Places API jest włączony w projekcie, musisz go włączyć:
Włączanie Places APIJeśli dodasz do klucza interfejsu API jakieś ograniczenia, pamiętaj, aby dodać do niego Places API. Więcej informacji znajdziesz w artykule Używanie kluczy interfejsu API.
Dodawanie klucza interfejsu API do aplikacji
- Otwórz plik
local.propertiesprojektu. Dodaj ten ciąg znaków, a następnie zastąp
YOUR_API_KEYwartością klucza interfejsu API:MAPS_API_KEY=YOUR_API_KEY
Podczas tworzenia aplikacji wtyczka Gradle obiektów tajnych dla Androida skopiuje klucz interfejsu API i udostępni go jako zmienną kompilacji w pliku manifestu Androida.
Tworzenie i uruchamianie aplikacji
Podłącz urządzenie z Androidem do komputera. Postępuj zgodnie z instrukcjami, aby włączyć opcje programisty na urządzeniu z Androidem i skonfigurować system tak, aby wykrywał urządzenie.
Możesz też skonfigurować urządzenie wirtualne za pomocą menedżera urządzenia wirtualnego z Androidem (AVD). Wybierając emulator, upewnij się, że wybierasz obraz, który zawiera interfejsy API Google. Więcej informacji znajdziesz w artykule Konfigurowanie projektu w Android Studio.
- W Android Studio kliknij opcję menu Uruchom (lub ikonę przycisku odtwarzania). Wybierz urządzenie zgodnie z instrukcjami.
Android Studio wywołuje Gradle, aby skompilować aplikację, a następnie uruchamia ją na urządzeniu lub w emulatorze. Powinna wyświetlić się mapa z kilkoma znacznikami wyśrodkowana na Twojej bieżącej lokalizacji, podobna do obrazu na tej stronie.
- Kliknij Pobierz miejsce, aby otworzyć listę miejsc (firm lub innych ciekawych miejsc) w pobliżu Twojej bieżącej lokalizacji. Aby zobaczyć listę miejsc, musisz przyznać dostęp do lokalizacji, gdy pojawi się prośba.
- Wybierz miejsce z listy. Na mapie zostanie dodany znacznik wybranego miejsca.
Rozwiązywanie problemów:
- Jeśli nie widzisz mapy, sprawdź, czy masz klucz interfejsu API i czy został on dodany do aplikacji w sposób opisany powyżej. Sprawdź, czy w dzienniku Android Monitor w Android Studio nie ma komunikatów o błędach dotyczących klucza interfejsu API.
- Jeśli na mapie jest tylko 1 znacznik wskazujący most Sydney Harbour Bridge (domyślna lokalizacja określona w aplikacji), sprawdź, czy aplikacja ma dostęp do lokalizacji. Aplikacja prosi o dostęp do lokalizacji w czasie działania zgodnie ze wzorcem opisanym w przewodniku po uprawnieniach na Androidzie. Pamiętaj, że uprawnienia możesz też ustawić bezpośrednio na urządzeniu, wybierając Ustawienia > Aplikacje > nazwa aplikacji > Uprawnienia > Lokalizacja. Szczegółowe informacje o obsłudze uprawnień w kodzie znajdziesz w poniższym przewodniku dotyczącym proszenia o dostęp do lokalizacji w aplikacji.
- Użyj narzędzi do debugowania w Android Studio, aby wyświetlić dzienniki i debugować aplikację.
Zrozumienie kodu
W tej części samouczka wyjaśniamy najważniejsze elementy aplikacji CurrentPlaceDetailsOnMap, aby pomóc Ci zrozumieć, jak utworzyć podobną aplikację.
Tworzenie instancji klienta Places API
Te obiekty są głównymi punktami wejścia do pakietu SDK Miejsc na Androida:
- Klasa
Placestworzy klientów pakietu SDK Miejsc na Androida i nimi zarządza. - Interfejs
PlacesClientpobiera bieżącą lokalizację urządzenia i miejsca w pobliżu.
Interfejs LocationServices jest głównym punktem wejścia do usług lokalizacyjnych na Androidzie.
Aby korzystać z interfejsów API, wykonaj te czynności w metodzie onCreate() fragmentu lub aktywności:
- Zainicjuj obiekt
Places. - Utwórz obiekt
PlacesClient. - Utwórz obiekt
FusedLocationProviderClient.
Na przykład:
Java
@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); // ... // Retrieve the content view that renders the map. setContentView(R.layout.activity_maps); // Construct a PlacesClient Places.initialize(getApplicationContext(), getString(R.string.maps_api_key)); placesClient = Places.createClient(this); // Construct a FusedLocationProviderClient. fusedLocationProviderClient = LocationServices.getFusedLocationProviderClient(this); }
Kotlin
override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) // ... // Retrieve the content view that renders the map. setContentView(R.layout.activity_maps) // Construct a PlacesClient Places.initialize(applicationContext, getString(R.string.maps_api_key)) placesClient = Places.createClient(this) // Construct a FusedLocationProviderClient. fusedLocationProviderClient = LocationServices.getFusedLocationProviderClient(this) }
Poproś o dostęp do lokalizacji
Aplikacja musi poprosić o dostęp do lokalizacji, aby określić lokalizację urządzenia i umożliwić użytkownikowi kliknięcie przycisku Moja lokalizacja na mapie.
W tym samouczku znajdziesz kod, który jest potrzebny do poproszenia o dostęp do lokalizacji. Więcej informacji znajdziesz w przewodniku po uprawnieniach Androida.
Dodaj uprawnienie jako element podrzędny elementu
<manifest>w pliku manifestu Androida:<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.currentplacedetailsonmap"> <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" /> </manifest>
Poproś o uprawnienia w czasie działania aplikacji, dając użytkownikowi możliwość zezwolenia na dostęp do lokalizacji lub odmowy. Poniższy kod sprawdza, czy użytkownik przyznał dostęp do lokalizacji. Jeśli nie, prosi o uprawnienia:
Java
private void getLocationPermission() { /* * Request location permission, so that we can get the location of the * device. The result of the permission request is handled by a callback, * onRequestPermissionsResult. */ if (ContextCompat.checkSelfPermission( this.getApplicationContext(), android.Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED) { locationPermissionGranted = true; } else { ActivityCompat.requestPermissions( this, new String[] {android.Manifest.permission.ACCESS_FINE_LOCATION}, PERMISSIONS_REQUEST_ACCESS_FINE_LOCATION); } }
Kotlin
private fun getLocationPermission() { /* * Request location permission, so that we can get the location of the * device. The result of the permission request is handled by a callback, * onRequestPermissionsResult. */ if (ContextCompat.checkSelfPermission( this.applicationContext, Manifest.permission.ACCESS_FINE_LOCATION, ) == PackageManager.PERMISSION_GRANTED ) { locationPermissionGranted = true } else { ActivityCompat.requestPermissions( this, arrayOf(Manifest.permission.ACCESS_FINE_LOCATION), PERMISSIONS_REQUEST_ACCESS_FINE_LOCATION, ) } }
Zastąp wywołanie zwrotne
onRequestPermissionsResult(), aby obsłużyć wynik prośby o uprawnienia:Java
@Override public void onRequestPermissionsResult( int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) { locationPermissionGranted = false; if (requestCode == PERMISSIONS_REQUEST_ACCESS_FINE_LOCATION) { // If request is cancelled, the // result arrays are empty. if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) { locationPermissionGranted = true; } } else { super.onRequestPermissionsResult(requestCode, permissions, grantResults); } updateLocationUI(); }
Kotlin
override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<String>, grantResults: IntArray) { locationPermissionGranted = false when (requestCode) { PERMISSIONS_REQUEST_ACCESS_FINE_LOCATION -> { // If request is cancelled, the result arrays are empty. if (grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED ) { locationPermissionGranted = true } } else -> super.onRequestPermissionsResult(requestCode, permissions, grantResults) } updateLocationUI() }
W dalszej części tego samouczka opisano metodę
updateLocationUI().
Dodawanie mapy
wyświetlać mapę za pomocą pakietu Maps SDK na Androida;
Dodaj element
<fragment>do pliku układu aktywnościactivity_maps.xml. Ten element definiujeSupportMapFragment, który działa jako kontener mapy i zapewnia dostęp do obiektuGoogleMap. W samouczku użyto fragmentu mapy z biblioteki pomocy Androida, aby zapewnić zgodność wsteczną z wcześniejszymi wersjami platformy Androida.<!-- Copyright 2020 Google LLC Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. --> <fragment xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/map" android:name="com.google.android.gms.maps.SupportMapFragment" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="com.example.currentplacedetailsonmap.MapsActivityCurrentPlace" />
W metodzie
onCreate()aktywności ustaw plik układu jako widok zawartości:Java
@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); // Retrieve the content view that renders the map. setContentView(R.layout.activity_maps); }
Kotlin
override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) // Retrieve the content view that renders the map. setContentView(R.layout.activity_maps) }
Zaimplementuj interfejs
OnMapReadyCallbacki zastąp metodęonMapReady(), aby skonfigurować mapę, gdy obiektGoogleMapjest dostępny:Java
@Override public void onMapReady(GoogleMap map) { this.map = map; // ... // Turn on the My Location layer and the related control on the map. updateLocationUI(); // Get the current location of the device and set the position of the map. getDeviceLocation(); }
Kotlin
override fun onMapReady(map: GoogleMap) { this.map = map // ... // Turn on the My Location layer and the related control on the map. updateLocationUI() // Get the current location of the device and set the position of the map. getDeviceLocation() }
W metodzie
onCreate()aktywności pobierz uchwyt do fragmentu mapy, wywołującFragmentManager.findFragmentById(). Następnie użyjgetMapAsync(), aby zarejestrować wywołanie zwrotne mapy:Java
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map); mapFragment.getMapAsync(this);
Kotlin
val mapFragment = supportFragmentManager .findFragmentById(R.id.map) as SupportMapFragment? mapFragment?.getMapAsync(this)
Napisz metodę
updateLocationUI(), aby ustawić elementy sterujące lokalizacją na mapie. Jeśli użytkownik zezwolił na dostęp do lokalizacji, włącz warstwę Moja lokalizacja i powiązany z nią element sterujący na mapie. W przeciwnym razie wyłącz warstwę i element sterujący, a bieżącą lokalizację ustaw na wartość null:Java
private void updateLocationUI() { if (map == null) { return; } try { if (locationPermissionGranted) { map.setMyLocationEnabled(true); map.getUiSettings().setMyLocationButtonEnabled(true); } else { map.setMyLocationEnabled(false); map.getUiSettings().setMyLocationButtonEnabled(false); lastKnownLocation = null; } } catch (SecurityException e) { Log.e("Exception: %s", e.getMessage()); } }
Kotlin
@SuppressLint("MissingPermission") private fun updateLocationUI() { if (map == null) { return } try { if (locationPermissionGranted) { map?.isMyLocationEnabled = true map?.uiSettings?.isMyLocationButtonEnabled = true } else { map?.isMyLocationEnabled = false map?.uiSettings?.isMyLocationButtonEnabled = false lastKnownLocation = null getLocationPermission() } } catch (e: SecurityException) { Log.e("Exception: %s", e.message, e) } }
Pobieranie lokalizacji urządzenia z Androidem i pozycjonowanie mapy
Użyj dostawcy uśrednionej lokalizacji, aby znaleźć ostatnią znaną lokalizację urządzenia, a następnie użyj tej lokalizacji do ustawienia mapy. W samouczku znajdziesz potrzebny kod. Więcej informacji o uzyskiwaniu lokalizacji urządzenia znajdziesz w przewodniku po dostawcy uśrednionej lokalizacji w interfejsach API lokalizacji Usług Google Play.
Java
private void getDeviceLocation() { /* * Get the best and most recent location of the device, which may be null in rare * cases when a location is not available. */ try { if (locationPermissionGranted) { Task<Location> locationResult = fusedLocationProviderClient.getLastLocation(); locationResult.addOnCompleteListener( this, 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. lastKnownLocation = task.getResult(); if (lastKnownLocation != null) { map.moveCamera( CameraUpdateFactory.newLatLngZoom( new LatLng( lastKnownLocation.getLatitude(), lastKnownLocation.getLongitude()), DEFAULT_ZOOM)); } } else { Log.d(TAG, "Current location is null. Using defaults."); Log.e(TAG, "Exception: %s", task.getException()); map.moveCamera( CameraUpdateFactory.newLatLngZoom( defaultLocation, DEFAULT_ZOOM)); map.getUiSettings().setMyLocationButtonEnabled(false); } } }); } } catch (SecurityException e) { Log.e("Exception: %s", e.getMessage(), e); } }
Kotlin
@SuppressLint("MissingPermission") private fun getDeviceLocation() { /* * Get the best and most recent location of the device, which may be null in rare * cases when a location is not available. */ try { if (locationPermissionGranted) { val locationResult = fusedLocationProviderClient.lastLocation locationResult.addOnCompleteListener(this) { task -> if (task.isSuccessful) { // Set the map's camera position to the current location of the device. lastKnownLocation = task.result if (lastKnownLocation != null) { map?.moveCamera( CameraUpdateFactory.newLatLngZoom( LatLng( lastKnownLocation!!.latitude, lastKnownLocation!!.longitude, ), DEFAULT_ZOOM.toFloat(), ), ) } } else { Log.d(TAG, "Current location is null. Using defaults.") Log.e(TAG, "Exception: %s", task.exception) map?.moveCamera( CameraUpdateFactory .newLatLngZoom(defaultLocation, DEFAULT_ZOOM.toFloat()), ) map?.uiSettings?.isMyLocationButtonEnabled = false } } } } catch (e: SecurityException) { Log.e("Exception: %s", e.message, e) } }
Pobieranie aktualnego miejsca
Użyj pakietu Places SDK for Android, aby uzyskać listę prawdopodobnych miejsc w bieżącej lokalizacji urządzenia. W tym kontekście miejsce to firma lub inny interesujący punkt.
W tym samouczku dowiesz się, jak pobrać aktualne miejsce, gdy użytkownik kliknie przycisk Pobierz miejsce. Użytkownik może wybrać miejsce z listy prawdopodobnych lokalizacji, a następnie dodać znacznik na mapie w wybranym miejscu. Samouczek zawiera kod potrzebny do interakcji z pakietem Places SDK na Androida. Więcej informacji znajdziesz w przewodniku na temat pobierania aktualnego miejsca.
- Utwórz plik układu (
current_place_menu.xml) dla menu opcji i zastąp metodęonCreateOptionsMenu(), aby skonfigurować menu opcji. Kod znajdziesz w dołączonej przykładowej aplikacji. - Zastąp metodę
onOptionsItemSelected(), aby uzyskać aktualne miejsce, gdy użytkownik kliknie opcję Pobierz miejsce:Java
@Override public boolean onOptionsItemSelected(MenuItem item) { if (item.getItemId() == R.id.option_get_place) { showCurrentPlace(); } return true; }
Kotlin
override fun onOptionsItemSelected(item: MenuItem): Boolean { if (item.itemId == R.id.option_get_place) { showCurrentPlace() } return true }
Utwórz metodę
showCurrentPlace(), aby uzyskać listę prawdopodobnych miejsc w bieżącej lokalizacji urządzenia:Java
private void showCurrentPlace() { if (map == null) { return; } // ... if (locationPermissionGranted) { // Use fields to define the data types to return. List<Place.Field> placeFields = Arrays.asList( Place.Field.DISPLAY_NAME, Place.Field.FORMATTED_ADDRESS, Place.Field.LOCATION); // Search around the device's last-known location, falling back to the center of the // map if the location is not available yet. LatLng center = lastKnownLocation != null ? new LatLng( lastKnownLocation.getLatitude(), lastKnownLocation.getLongitude()) : map.getCameraPosition().target; CircularBounds searchArea = CircularBounds.newInstance(center, SEARCH_RADIUS_METERS); // Use the builder to create a SearchNearbyRequest that returns the closest places // first. SearchNearbyRequest request = SearchNearbyRequest.builder(searchArea, placeFields) .setMaxResultCount(M_MAX_ENTRIES) .setRankPreference(SearchNearbyRequest.RankPreference.DISTANCE) .build(); // Get the likely places - that is, the businesses and other points of interest that // are closest to the device's current location. final Task<SearchNearbyResponse> placeResult = placesClient.searchNearby(request); placeResult.addOnCompleteListener( new OnCompleteListener<SearchNearbyResponse>() { @Override public void onComplete(@NonNull Task<SearchNearbyResponse> task) { if (task.isSuccessful() && task.getResult() != null) { List<Place> responsePlaces = task.getResult().getPlaces(); int count = Math.min(responsePlaces.size(), M_MAX_ENTRIES); List<PlaceItemUiModel> likelyPlaces = new ArrayList<>(); for (int i = 0; i < count; i++) { PlaceItemUiModel model = toUiModel(responsePlaces.get(i)); if (model != null) { likelyPlaces.add(model); } } // Show a dialog offering the user the list of likely places, and // add a marker at the selected place. MapsActivityCurrentPlace.this.openPlacesDialog(likelyPlaces); } else { Log.e(TAG, "Exception: %s", task.getException()); } } }); } else { // The user has not granted permission. Log.i(TAG, "The user did not grant location permission."); // Add a default marker, because the user hasn't selected a place. map.addMarker( new MarkerOptions() .title(getString(R.string.default_info_title)) .position(defaultLocation) .snippet(getString(R.string.default_info_snippet))); // Prompt the user for permission. getLocationPermission(); } }
Kotlin
private fun showCurrentPlace() { val map = map ?: return // ... if (locationPermissionGranted) { // Use fields to define the data types to return. val placeFields = listOf( Place.Field.DISPLAY_NAME, Place.Field.FORMATTED_ADDRESS, Place.Field.LOCATION, ) // Search around the device's last-known location, falling back to the center of // the map if the location is not available yet. val center = lastKnownLocation?.let { LatLng(it.latitude, it.longitude) } ?: map.cameraPosition.target val searchArea = CircularBounds.newInstance(center, SEARCH_RADIUS_METERS) // Use the builder to create a SearchNearbyRequest that returns the closest places // first. val request = SearchNearbyRequest.builder(searchArea, placeFields) .setMaxResultCount(M_MAX_ENTRIES) .setRankPreference(SearchNearbyRequest.RankPreference.DISTANCE) .build() // Get the likely places - that is, the businesses and other points of interest that // are closest to the device's current location. val placeResult = placesClient.searchNearby(request) placeResult.addOnCompleteListener { task -> if (task.isSuccessful && task.result != null) { val likelyPlaces = task.result.places .take(M_MAX_ENTRIES) .mapNotNull { it.toUiModel() } // Show a dialog offering the user the list of likely places, and add a // marker at the selected place. openPlacesDialog(likelyPlaces) } else { Log.e(TAG, "Exception: %s", task.exception) } } } else { // The user has not granted permission. Log.i(TAG, "The user did not grant location permission.") // Add a default marker, because the user hasn't selected a place. map.addMarker( MarkerOptions() .title(getString(R.string.default_info_title)) .position(defaultLocation) .snippet(getString(R.string.default_info_snippet)), ) // Prompt the user for permission. getLocationPermission() } }
Utwórz metodę
openPlacesDialog(), aby wyświetlić formularz, który pozwoli użytkownikowi wybrać miejsce z listy prawdopodobnych miejsc. Dodaj znacznik na mapie dla wybranego miejsca. Treść znacznika zawiera nazwę i adres miejsca oraz wszelkie informacje o autorze dostarczone przez interfejs API:Java
void openPlacesDialog(List<PlaceItemUiModel> likelyPlaces) { // ... // Ask the user to choose the place where they are now. DialogInterface.OnClickListener listener = new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { // The "which" argument contains the position of the selected item. PlaceItemUiModel selectedPlace = likelyPlaces.get(which); // Add a marker for the selected place, with an info window // showing information about that place. map.addMarker( new MarkerOptions() .title(selectedPlace.title) .position(selectedPlace.position) .snippet(selectedPlace.snippet)); // Position the map's camera at the location of the marker. map.moveCamera( CameraUpdateFactory.newLatLngZoom( selectedPlace.position, DEFAULT_ZOOM)); } }; // Display the dialog. String[] titles = new String[likelyPlaces.size()]; for (int i = 0; i < likelyPlaces.size(); i++) { titles[i] = likelyPlaces.get(i).title; } new AlertDialog.Builder(this) .setTitle(R.string.pick_place) .setItems(titles, listener) .show(); }
Kotlin
internal fun openPlacesDialog(likelyPlaces: List<PlaceItemUiModel>) { // ... // Ask the user to choose the place where they are now. val listener = DialogInterface.OnClickListener { _, which -> // The "which" argument contains the position of the selected item. val selectedPlace = likelyPlaces[which] // Add a marker for the selected place, with an info window // showing information about that place. selectedMarker = map?.addMarker( MarkerOptions() .title(selectedPlace.title) .position(selectedPlace.position) .snippet(selectedPlace.snippet), ) // Position the map's camera at the location of the marker. map?.moveCamera( CameraUpdateFactory.newLatLngZoom( selectedPlace.position, DEFAULT_ZOOM.toFloat(), ), ) } // Display the dialog. val titles = likelyPlaces.map { it.title }.toTypedArray() AlertDialog.Builder(this) .setTitle(R.string.pick_place) .setItems(titles, listener) .show() }
Utwórz niestandardowy układ treści okna informacyjnego. Dzięki temu w oknie informacyjnym można wyświetlić kilka wierszy treści. Najpierw dodaj plik układu XML
custom_info_contents.xmlzawierający widok tekstu dla tytułu okna informacyjnego i inny widok tekstu dla fragmentu (czyli treści tekstowej okna informacyjnego):<?xml version="1.0" encoding="utf-8"?> <!-- Copyright 2020 Google LLC Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. --> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layoutDirection="locale" android:orientation="vertical"> <TextView android:id="@+id/title" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_horizontal" android:textColor="#ff000000" android:textStyle="bold" /> <TextView android:id="@+id/snippet" android:layout_width="wrap_content" android:layout_height="wrap_content" android:textColor="#ff7f7f7f" /> </LinearLayout>
Zaimplementuj interfejs
InfoWindowAdapter, aby rozszerzyć układ i wczytać zawartość okna informacyjnego:Java
// Use a custom info window adapter to handle multiple lines of text in the // info window contents. this.map.setInfoWindowAdapter( new GoogleMap.InfoWindowAdapter() { @Override // Return null here, so that getInfoContents() is called next. public View getInfoWindow(Marker arg0) { return null; } @Override public View getInfoContents(Marker marker) { // Inflate the layouts for the info window, title and snippet. View infoWindow = getLayoutInflater() .inflate( R.layout.custom_info_contents, (FrameLayout) findViewById(R.id.map), false); TextView title = infoWindow.findViewById(R.id.title); title.setText(marker.getTitle()); TextView snippet = infoWindow.findViewById(R.id.snippet); snippet.setText(marker.getSnippet()); return infoWindow; } });
Kotlin
// Use a custom info window adapter to handle multiple lines of text in the // info window contents. this.map?.setInfoWindowAdapter(object : InfoWindowAdapter { // Return null here, so that getInfoContents() is called next. override fun getInfoWindow(arg0: Marker): View? = null override fun getInfoContents(marker: Marker): View { // Inflate the layouts for the info window, title and snippet. val infoWindow = layoutInflater.inflate( R.layout.custom_info_contents, findViewById<FrameLayout>(R.id.map), false, ) val title = infoWindow.findViewById<TextView>(R.id.title) title.text = marker.title val snippet = infoWindow.findViewById<TextView>(R.id.snippet) snippet.text = marker.snippet return infoWindow } })
Zapisywanie stanu mapy
Zapisz pozycję kamery na mapie i lokalizację urządzenia. Gdy użytkownik obróci urządzenie z Androidem lub zmieni konfigurację, platforma Androida niszczy i ponownie tworzy aktywność w Mapach. Aby zapewnić użytkownikom płynne działanie, warto zapisać odpowiedni stan aplikacji i przywrócić go w razie potrzeby.
Ten samouczek zawiera cały kod potrzebny do zapisania stanu mapy. Więcej informacji znajdziesz w przewodniku po pakiecie savedInstanceState.
W aktywności w Mapach skonfiguruj wartości kluczy do przechowywania stanu aktywności:
Java
private static final String KEY_CAMERA_POSITION = "camera_position"; private static final String KEY_LOCATION = "location";
Kotlin
private const val KEY_CAMERA_POSITION = "camera_position" private const val KEY_LOCATION = "location"
Zaimplementuj wywołanie zwrotne
onSaveInstanceState(), aby zapisać stan, gdy aktywność zostanie wstrzymana:Java
@Override protected void onSaveInstanceState(Bundle outState) { if (map != null) { outState.putParcelable(KEY_CAMERA_POSITION, map.getCameraPosition()); outState.putParcelable(KEY_LOCATION, lastKnownLocation); } super.onSaveInstanceState(outState); }
Kotlin
override fun onSaveInstanceState(outState: Bundle) { map?.let { map -> outState.putParcelable(KEY_CAMERA_POSITION, map.cameraPosition) outState.putParcelable(KEY_LOCATION, lastKnownLocation) } super.onSaveInstanceState(outState) }
W metodzie
onCreate()aktywności pobierz lokalizację urządzenia i pozycję kamery mapy, jeśli zostały wcześniej zapisane:Java
// Retrieve location and camera position from saved instance state. if (savedInstanceState != null) { lastKnownLocation = savedInstanceState.getParcelable(KEY_LOCATION); cameraPosition = savedInstanceState.getParcelable(KEY_CAMERA_POSITION); }
Kotlin
if (savedInstanceState != null) { lastKnownLocation = savedInstanceState.getParcelable(KEY_LOCATION) cameraPosition = savedInstanceState.getParcelable(KEY_CAMERA_POSITION) }