为地址表单添加地点自动补全功能

为表单添加地点自动补全功能可以帮助用户在输入配送地址以及结算信息或活动信息中的地址信息时减少按键操作和错误。本教程逐步介绍了如何为输入字段添加地点自动补全功能、如何使用用户所选地址的地址组成部分填充地址表单字段，以及如何在地图上显示所选的地址以帮助直观呈现确认信息。

视频：通过地点自动补全功能提升地址表单体验

地址表单

Android

iOS

Web

Google Maps Platform 提供了适用于移动平台和网站的地点自动补全 widget。如上图所示，该 widget 提供了一个内置自动补全功能的搜索对话框，甚至可让您针对位置范围的搜索进行优化。

获取代码

从 GitHub 克隆或下载 Google Places SDK for Android 演示版代码库。

查看 Java 版本的 activity：

    /*
 * Copyright 2022 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
 *
 *     https://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.placesdemo;

import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.content.res.Resources;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.ViewStub;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.Toast;

import androidx.activity.result.ActivityResultLauncher;
import androidx.activity.result.contract.ActivityResultContracts;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.content.ContextCompat;

import com.example.placesdemo.databinding.AutocompleteAddressActivityBinding;
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.GoogleMapOptions;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MapStyleOptions;
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.AddressComponent;
import com.google.android.libraries.places.api.model.AddressComponents;
import com.google.android.libraries.places.api.model.Place;
import com.google.android.libraries.places.api.model.TypeFilter;
import com.google.android.libraries.places.api.net.PlacesClient;
import com.google.android.libraries.places.widget.Autocomplete;
import com.google.android.libraries.places.widget.model.AutocompleteActivityMode;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import static android.Manifest.permission.ACCESS_FINE_LOCATION;
import static com.google.maps.android.SphericalUtil.computeDistanceBetween;

/**
 * Activity for using Place Autocomplete to assist filling out an address form.
 */
@SuppressWarnings("FieldCanBeLocal")
public class AutocompleteAddressActivity extends AppCompatActivity implements OnMapReadyCallback {

    private static final String TAG = "ADDRESS_AUTOCOMPLETE";
    private static final String MAP_FRAGMENT_TAG = "MAP";
    private LatLng coordinates;
    private boolean checkProximity = false;
    private SupportMapFragment mapFragment;
    private GoogleMap map;
    private Marker marker;
    private PlacesClient placesClient;
    private View mapPanel;
    private LatLng deviceLocation;
    private static final double acceptedProximity = 150;

    private AutocompleteAddressActivityBinding binding;

    View.OnClickListener startAutocompleteIntentListener = view -> {
        view.setOnClickListener(null);
        startAutocompleteIntent();
    };

    private final ActivityResultLauncher<Intent> startAutocomplete = registerForActivityResult(
            new ActivityResultContracts.StartActivityForResult(),
            result -> {
                if (result.getResultCode() == Activity.RESULT_OK) {
                    Intent intent = result.getData();
                    if (intent != null) {
                        Place place = Autocomplete.getPlaceFromIntent(intent);

                        // Write a method to read the address components from the Place
                        // and populate the form with the address components
                        Log.d(TAG, "Place: " + place.getAddressComponents());
                        fillInAddress(place);
                    }
                } else if (result.getResultCode() == Activity.RESULT_CANCELED) {
                    // The user canceled the operation.
                    Log.i(TAG, "User canceled autocomplete");
                }
            });

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent intent) {
        super.onActivityResult(requestCode, resultCode, intent);
        binding.autocompleteAddress1.setOnClickListener(startAutocompleteIntentListener);
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        binding = AutocompleteAddressActivityBinding.inflate(getLayoutInflater());
        setContentView(binding.getRoot());

        // Retrieve a PlacesClient (previously initialized - see MainActivity)
        placesClient = Places.createClient(this);

        // Attach an Autocomplete intent to the Address 1 EditText field
        binding.autocompleteAddress1.setOnClickListener(startAutocompleteIntentListener);

        // Update checkProximity when user checks the checkbox
        CheckBox checkProximityBox = findViewById(R.id.checkbox_proximity);
        checkProximityBox.setOnCheckedChangeListener((view, isChecked) -> {
            // Set the boolean to match user preference for when the Submit button is clicked
            checkProximity = isChecked;
        });

        // Submit and optionally check proximity
        Button saveButton = findViewById(R.id.autocomplete_save_button);
        saveButton.setOnClickListener(v -> saveForm());

        // Reset the form
        Button resetButton = findViewById(R.id.autocomplete_reset_button);
        resetButton.setOnClickListener(v -> clearForm());
    }

    private void startAutocompleteIntent() {

        // Set the fields to specify which types of place data to
        // return after the user has made a selection.
        List<Place.Field> fields = Arrays.asList(Place.Field.ADDRESS_COMPONENTS,
                Place.Field.LAT_LNG, Place.Field.VIEWPORT);

        // Build the autocomplete intent with field, country, and type filters applied
        Intent intent = new Autocomplete.IntentBuilder(AutocompleteActivityMode.OVERLAY, fields)
                .setCountries(Arrays.asList("US"))
                .setTypesFilter(new ArrayList<String>() {{
                    add(TypeFilter.ADDRESS.toString().toLowerCase());
                }})
                .build(this);
        startAutocomplete.launch(intent);
    }

    @Override
    public void onMapReady(@NonNull GoogleMap googleMap) {
        map = googleMap;
        try {
            // Customise the styling of the base map using a JSON object defined
            // in a string resource.
            boolean success = map.setMapStyle(
                    MapStyleOptions.loadRawResourceStyle(this, R.raw.style_json));

            if (!success) {
                Log.e(TAG, "Style parsing failed.");
            }
        } catch (Resources.NotFoundException e) {
            Log.e(TAG, "Can't find style. Error: ", e);
        }
        map.moveCamera(CameraUpdateFactory.newLatLngZoom(coordinates, 15f));
        marker = map.addMarker(new MarkerOptions().position(coordinates));
    }

    private void fillInAddress(Place place) {
        AddressComponents components = place.getAddressComponents();
        StringBuilder address1 = new StringBuilder();
        StringBuilder postcode = new StringBuilder();

        // Get each component of the address from the place details,
        // and then fill-in the corresponding field on the form.
        // Possible AddressComponent types are documented at https://goo.gle/32SJPM1
        if (components != null) {
            for (AddressComponent component : components.asList()) {
                String type = component.getTypes().get(0);
                switch (type) {
                    case "street_number": {
                        address1.insert(0, component.getName());
                        break;
                    }

                    case "route": {
                        address1.append(" ");
                        address1.append(component.getShortName());
                        break;
                    }

                    case "postal_code": {
                        postcode.insert(0, component.getName());
                        break;
                    }

                    case "postal_code_suffix": {
                        postcode.append("-").append(component.getName());
                        break;
                    }

                    case "locality":
                        binding.autocompleteCity.setText(component.getName());
                        break;

                    case "administrative_area_level_1": {
                        binding.autocompleteState.setText(component.getShortName());
                        break;
                    }

                    case "country":
                        binding.autocompleteCountry.setText(component.getName());
                        break;
                }
            }
        }

        binding.autocompleteAddress1.setText(address1.toString());
        binding.autocompletePostal.setText(postcode.toString());

        // After filling the form with address components from the Autocomplete
        // prediction, set cursor focus on the second address line to encourage
        // entry of sub-premise information such as apartment, unit, or floor number.
        binding.autocompleteAddress2.requestFocus();

        // Add a map for visual confirmation of the address
        showMap(place);
    }

    private void showMap(Place place) {
        coordinates = place.getLatLng();

        // It isn't possible to set a fragment's id programmatically so we set a tag instead and
        // search for it using that.
        mapFragment = (SupportMapFragment)
                getSupportFragmentManager().findFragmentByTag(MAP_FRAGMENT_TAG);

        // We only create a fragment if it doesn't already exist.
        if (mapFragment == null) {
            mapPanel = ((ViewStub) findViewById(R.id.stub_map)).inflate();
            GoogleMapOptions mapOptions = new GoogleMapOptions();
            mapOptions.mapToolbarEnabled(false);

            // To programmatically add the map, we first create a SupportMapFragment.
            mapFragment = SupportMapFragment.newInstance(mapOptions);

            // Then we add it using a FragmentTransaction.
            getSupportFragmentManager()
                    .beginTransaction()
                    .add(R.id.confirmation_map, mapFragment, MAP_FRAGMENT_TAG)
                    .commit();
            mapFragment.getMapAsync(this);
        } else {
            updateMap(coordinates);
        }
    }

    private void updateMap(LatLng latLng) {
        marker.setPosition(latLng);
        map.moveCamera(CameraUpdateFactory.newLatLngZoom(latLng, 15f));
        if (mapPanel.getVisibility() == View.GONE) {
            mapPanel.setVisibility(View.VISIBLE);
        }
    }

    private void saveForm() {
        Log.d(TAG, "checkProximity = " + checkProximity);
        if (checkProximity) {
            checkLocationPermissions();
        } else {
            Toast.makeText(
                            this,
                            R.string.autocomplete_skipped_message,
                            Toast.LENGTH_SHORT)
                    .show();
        }
    }

    private void clearForm() {
        binding.autocompleteAddress1.setText("");
        binding.autocompleteAddress2.getText().clear();
        binding.autocompleteCity.getText().clear();
        binding.autocompleteState.getText().clear();
        binding.autocompletePostal.getText().clear();
        binding.autocompleteCountry.getText().clear();
        if (mapPanel != null) {
            mapPanel.setVisibility(View.GONE);
        }
        binding.autocompleteAddress1.requestFocus();
    }

    // Register the permissions callback, which handles the user's response to the
    // system permissions dialog. Save the return value, an instance of
    // ActivityResultLauncher, as an instance variable.
    private final ActivityResultLauncher<String> requestPermissionLauncher =
            registerForActivityResult(new ActivityResultContracts.RequestPermission(), isGranted -> {
                if (isGranted) {
                    // Since ACCESS_FINE_LOCATION is the only permission in this sample,
                    // run the location comparison task once permission is granted.
                    // Otherwise, check which permission is granted.
                    getAndCompareLocations();
                } else {
                    // Fallback behavior if user denies permission
                    Log.d(TAG, "User denied permission");
                }
            });

    private void checkLocationPermissions() {
        if (ContextCompat.checkSelfPermission(this, ACCESS_FINE_LOCATION)
                == PackageManager.PERMISSION_GRANTED) {
            getAndCompareLocations();
        } else {
            requestPermissionLauncher.launch(
                    ACCESS_FINE_LOCATION);
        }
    }

    @SuppressLint("MissingPermission")
    private void getAndCompareLocations() {
        // TODO: Detect and handle if user has entered or modified the address manually and update
        // the coordinates variable to the Lat/Lng of the manually entered address. May use
        // Geocoding API to convert the manually entered address to a Lat/Lng.
        LatLng enteredLocation = coordinates;
        map.setMyLocationEnabled(true);

        FusedLocationProviderClient fusedLocationClient =
                LocationServices.getFusedLocationProviderClient(this);

        fusedLocationClient.getLastLocation()
                .addOnSuccessListener(this, location -> {
                    // Got last known location. In some rare situations this can be null.
                    if (location == null) {
                        return;
                    }

                    deviceLocation = new LatLng(location.getLatitude(), location.getLongitude());
                    Log.d(TAG, "device location = " + deviceLocation);
                    Log.d(TAG, "entered location = " + enteredLocation.toString());

                    // Use the computeDistanceBetween function in the Maps SDK for Android Utility Library
                    // to use spherical geometry to compute the distance between two Lat/Lng points.
                    double distanceInMeters = computeDistanceBetween(deviceLocation, enteredLocation);
                    if (distanceInMeters <= acceptedProximity) {
                        Log.d(TAG, "location matched");
                        // TODO: Display UI based on the locations matching
                    } else {
                        Log.d(TAG, "location not matched");
                        // TODO: Display UI based on the locations not matching
                    }
                });
    }
}

启用 API

若要实现这些建议的做法，您必须在 Google Cloud 控制台中启用以下 API：

如需详细了解设置，请参阅设置您的 Google Cloud 项目。

为输入字段添加自动补全功能

本部分介绍了如何为地址表单添加地点自动补全功能。

添加地点自动补全 widget

在 Android 中，您可以使用自动补全 intent 来添加自动补全 widget，该 intent 可从地址行 1 的输入字段（用户将在此开始输入地址）启动地点自动补全功能。用户开始输入时，将可以从自动补全预测结果列表中选择地址。

首先，使用 ActivityResultLauncher 准备一个 activity 启动器，用于监听已启动 activity 的结果。结果回调将包含一个与用户从自动补全预测结果中选择的地址对应的 Place 对象。

    private final ActivityResultLauncher<Intent> startAutocomplete = registerForActivityResult(
            new ActivityResultContracts.StartActivityForResult(),
            result -> {
                if (result.getResultCode() == Activity.RESULT_OK) {
                    Intent intent = result.getData();
                    if (intent != null) {
                        Place place = Autocomplete.getPlaceFromIntent(intent);

                        // Write a method to read the address components from the Place
                        // and populate the form with the address components
                        Log.d(TAG, "Place: " + place.getAddressComponents());
                        fillInAddress(place);
                    }
                } else if (result.getResultCode() == Activity.RESULT_CANCELED) {
                    // The user canceled the operation.
                    Log.i(TAG, "User canceled autocomplete");
                }
            });

接下来，定义地点自动补全 intent 的字段、位置和类型属性，并使用 Autocomplete.IntentBuilder 进行构建。最后，使用上一个代码示例中定义的 ActivityResultLauncher 启动 intent。

    private void startAutocompleteIntent() {

        // Set the fields to specify which types of place data to
        // return after the user has made a selection.
        List<Place.Field> fields = Arrays.asList(Place.Field.ADDRESS_COMPONENTS,
                Place.Field.LAT_LNG, Place.Field.VIEWPORT);

        // Build the autocomplete intent with field, country, and type filters applied
        Intent intent = new Autocomplete.IntentBuilder(AutocompleteActivityMode.OVERLAY, fields)
                .setCountries(Arrays.asList("US"))
                .setTypesFilter(new ArrayList<String>() {{
                    add(TypeFilter.ADDRESS.toString().toLowerCase());
                }})
                .build(this);
        startAutocomplete.launch(intent);
    }

处理地点自动补全功能返回的地址

之前定义 ActivityResultLauncher 时还定义了回调中返回 activity 结果时应执行的操作。如果用户选择了某个预测的地址，系统将在结果对象中包含的 intent 中提供该地址。由于 intent 是通过 Autocomplete.IntentBuilder 构建的，因此 Autocomplete.getPlaceFromIntent() 方法可以从中提取 Place 对象。

    private final ActivityResultLauncher<Intent> startAutocomplete = registerForActivityResult(
            new ActivityResultContracts.StartActivityForResult(),
            result -> {
                if (result.getResultCode() == Activity.RESULT_OK) {
                    Intent intent = result.getData();
                    if (intent != null) {
                        Place place = Autocomplete.getPlaceFromIntent(intent);

                        // Write a method to read the address components from the Place
                        // and populate the form with the address components
                        Log.d(TAG, "Place: " + place.getAddressComponents());
                        fillInAddress(place);
                    }
                } else if (result.getResultCode() == Activity.RESULT_CANCELED) {
                    // The user canceled the operation.
                    Log.i(TAG, "User canceled autocomplete");
                }
            });

然后，调用 Place.getAddressComponents()，并将各个地址组成部分与其在地址表单中的对应输入字段进行匹配，从而在字段中填充用户所选地点的值。

本页面获取代码部分下提供的示例代码的 fillInAddress 方法分享了填充地址表单字段的示例实现。

从预测结果（而不是手动输入的地址）捕获地址数据不仅有助于确保地址准确无误，还可确保地址是可配送到的已知地址，同时还可减少用户的按键操作。

实现地点自动补全功能时的注意事项

如果您还想使用除 widget 以外的其他方式，地点自动补全功能提供的多种选项可以帮助您灵活实现。您可以结合使用多种服务，获取正确匹配位置所需的准确信息。

  • 对于地址表单，请将 types 参数设为 address，以将匹配地址限制为完整的街道地址。您可以详细了解地点自动补全请求支持的类型。

  • 如果您不需要在世界范围内进行搜索，请设定适当的限制和偏向。您可以使用多个参数来设定偏向和限制，从而将所有匹配结果限制在特定区域。

    • 使用 RectangularBounds 设置矩形边界，通过这些边界来限定一个区域，并使用 setLocationRestriction() 确保系统仅返回这些区域中的地址。

    • 使用 setCountries() 将响应限制为一组特定的国家/地区。

  • 使字段保持可修改状态，以防匹配结果中缺失某些字段，并可让客户根据需要更新地址。由于地点自动补全功能返回的大多数地址都不包含 subpremise 编号（例如公寓、套房或单元编号），因此您可以重点关注地址行 2，鼓励用户根据需要填写相关信息。

直观呈现地址的确认信息

在用户输入地址时，在地图上向其直观呈现地址的确认信息。这能再次保证用户地址信息填写正确。

在下图中，输入的地址下方显示了一个地图，且地图上输入的地址所在位置放置了一枚图钉。

下例遵循了在 Android 中添加地图的基本步骤。如需了解详情，请参阅相关文档。

添加 SupportMapFragment

首先，将 SupportMapFragment fragment 添加到布局 XML 文件中。

    <fragment
        android:name="com.google.android.gms.maps.SupportMapFragment"
        android:id="@+id/confirmation_map"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

然后，以编程方式添加该 fragment（如果不存在的话）。

    private void showMap(Place place) {
        coordinates = place.getLatLng();

        // It isn't possible to set a fragment's id programmatically so we set a tag instead and
        // search for it using that.
        mapFragment = (SupportMapFragment)
                getSupportFragmentManager().findFragmentByTag(MAP_FRAGMENT_TAG);

        // We only create a fragment if it doesn't already exist.
        if (mapFragment == null) {
            mapPanel = ((ViewStub) findViewById(R.id.stub_map)).inflate();
            GoogleMapOptions mapOptions = new GoogleMapOptions();
            mapOptions.mapToolbarEnabled(false);

            // To programmatically add the map, we first create a SupportMapFragment.
            mapFragment = SupportMapFragment.newInstance(mapOptions);

            // Then we add it using a FragmentTransaction.
            getSupportFragmentManager()
                    .beginTransaction()
                    .add(R.id.confirmation_map, mapFragment, MAP_FRAGMENT_TAG)
                    .commit();
            mapFragment.getMapAsync(this);
        } else {
            updateMap(coordinates);
        }
    }

获取 fragment 的句柄并注册回调函数

  1. 若要获取相应 fragment 的句柄，请调用 FragmentManager.findFragmentById 方法，并向其传递布局文件中的 fragment 的资源 ID。如果您是以动态方式添加该 fragment 的，请跳过此步骤，因为您已经检索了句柄。

  2. 调用 getMapAsync 方法，在 fragment 上设置回调。

例如（假如是以静态方式添加 fragment 的）：

Kotlin

val mapFragment = supportFragmentManager
    .findFragmentById(R.id.map) as SupportMapFragment
mapFragment.getMapAsync(this)

Java

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

设置地图样式并向地图添加标记

在地图准备就绪后，设置样式、设置相机中心位置，并在输入的地址的坐标处添加标记。以下代码使用的是 JSON 对象中定义的样式，您也可以加载已使用云端地图样式设置功能定义的地图 ID。

    @Override
    public void onMapReady(@NonNull GoogleMap googleMap) {
        map = googleMap;
        try {
            // Customise the styling of the base map using a JSON object defined
            // in a string resource.
            boolean success = map.setMapStyle(
                    MapStyleOptions.loadRawResourceStyle(this, R.raw.style_json));

            if (!success) {
                Log.e(TAG, "Style parsing failed.");
            }
        } catch (Resources.NotFoundException e) {
            Log.e(TAG, "Can't find style. Error: ", e);
        }
        map.moveCamera(CameraUpdateFactory.newLatLngZoom(coordinates, 15f));
        marker = map.addMarker(new MarkerOptions().position(coordinates));
    }

（查看完整的代码示例）

停用地图控件

如需显示位置而不显示其他地图控件（例如罗盘、工具栏或其他内置功能），以确保地图简单明了，不妨考虑停用您认为不需要的控件。在 Android 上，另一种方法是启用精简模式来提供一定程度的互动。