如何从谷歌地图中获取搜索建议？

Question

我需要在搜索栏中输入时，获得关于城市/街道/村庄的建议列表。我发现我必须实现内容提供程序并且我已经实现了它。现在，无论我输入什么，我都会得到相同的结果：

"搜索结果"

而Google Places应该返回正确的地点列表。有人能帮我吗？我如何使我的搜索工作像googlemaps一样？（我的意思是建议，Geocoder的事情已经完成了）。非常感谢。

- Csabi

Answer 1

以下是我在遇到类似问题时使用的代码片段。

这是我的 PlacesAutoCompleteAdapter.java 文件。

package com.inukshk.adapter;

import java.util.ArrayList;

import android.content.Context;
import android.widget.ArrayAdapter;
import android.widget.Filter;
import android.widget.Filterable;

import com.inukshk.CreateInukshk.CreateInukshk;

public class PlacesAutoCompleteAdapter extends ArrayAdapter<String> implements
        Filterable {
    private ArrayList<String> resultList;

    public PlacesAutoCompleteAdapter(Context context, int textViewResourceId) {
        super(context, textViewResourceId);
    }

    @Override
    public int getCount() {
        return resultList.size();
    }

    @Override
    public String getItem(int index) {
        return resultList.get(index);
    }

    @Override
    public Filter getFilter() {
        Filter filter = new Filter() {
            @Override
            protected FilterResults performFiltering(CharSequence constraint) {
                FilterResults filterResults = new FilterResults();
                if (constraint != null) {
                    // Retrieve the autocomplete results.

                    resultList = CreateInukshk.autocomplete(constraint
                            .toString());

                    // Assign the data to the FilterResults
                    filterResults.values = resultList;
                    filterResults.count = resultList.size();
                }
                return filterResults;
            }

            @Override
            protected void publishResults(CharSequence constraint,
                    FilterResults results) {
                if (results != null && results.count > 0) {
                    notifyDataSetChanged();
                } else {
                    notifyDataSetInvalidated();
                }
            }
        };
        return filter;
    }
}

以下是您在活动的 OnCreate() 方法中应该执行的步骤。

autoCompView = (AutoCompleteTextView) findViewById(R.id.editloc);
        autoCompView.setAdapter(new PlacesAutoCompleteAdapter(this,
                R.layout.list_item));

这是我在应用程序中使用的静态字符串。

private static final String PLACES_API_BASE = "https://maps.googleapis.com/maps/api/place";
    private static final String TYPE_AUTOCOMPLETE = "/autocomplete";
    private static final String OUT_JSON = "/json";     
    private static final String API_KEY = "YOUR API KEY";

最后这是你在适配器中将要使用的方法。

public static ArrayList<String> autocomplete(String input) {

        ArrayList<String> resultList = null;

        HttpURLConnection conn = null;
        StringBuilder jsonResults = new StringBuilder();
        try {
            StringBuilder sb = new StringBuilder(PLACES_API_BASE
                    + TYPE_AUTOCOMPLETE + OUT_JSON);
            sb.append("?sensor=false&key=" + API_KEY);
            // sb.append("&components=country:uk");
            sb.append("&input=" + URLEncoder.encode(input, "utf8"));

            URL url = new URL(sb.toString());
            conn = (HttpURLConnection) url.openConnection();
            InputStreamReader in = new InputStreamReader(conn.getInputStream());

            // Load the results into a StringBuilder
            int read;
            char[] buff = new char[1024];
            while ((read = in.read(buff)) != -1) {
                jsonResults.append(buff, 0, read);
            }
        } catch (MalformedURLException e) {
            Log.e(TAG, "Error processing Places API URL", e);
            return resultList;
        } catch (IOException e) {
            Log.e(TAG, "Error connecting to Places API", e);
            return resultList;
        } finally {
            if (conn != null) {
                conn.disconnect();
            }
        }

        try {
            // Create a JSON object hierarchy from the results
            JSONObject jsonObj = new JSONObject(jsonResults.toString());
            JSONArray predsJsonArray = jsonObj.getJSONArray("predictions");

            // Extract the Place descriptions from the results
            resultList = new ArrayList<String>(predsJsonArray.length());
            for (int i = 0; i < predsJsonArray.length(); i++) {
                resultList.add(predsJsonArray.getJSONObject(i).getString(
                        "description"));
            }

        } catch (JSONException e) {
            Log.e(TAG, "Cannot process JSON results", e);
        }

        return resultList;
    }

我猜您已将list_item.xml指定为以下内容：

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content" android:layout_height="wrap_content" />

试一试。希望它能对您有所帮助。

- Bhavesh Patadiya