android - 如何在 Android 应用程序中集成谷歌地图

Question

我想在我的 Android 应用程序中集成用于在 google maps android api v2 和地理编码 api 中定位用户输入地址的 Google map

下面是我的代码:

MainActivity.java

package com.example.googlemaps;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.List;

import org.json.JSONObject;

import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

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;
import com.google.android.gms.maps.model.MarkerOptions;

public class MainActivity extends FragmentActivity {


    Button mBtnFind;
    GoogleMap mMap;
    EditText etPlace;


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

        // Getting reference to the find button
        mBtnFind = (Button) findViewById(R.id.btn_show);

        // Getting reference to the SupportMapFragment
        SupportMapFragment mapFragment = (SupportMapFragment)getSupportFragmentManager().findFragmentById(R.id.map); 

        // Getting reference to the Google Map
        mMap = mapFragment.getMap();

        // Getting reference to EditText
        etPlace = (EditText) findViewById(R.id.et_place);

        // Setting click event listener for the find button
        mBtnFind.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {   
                // Getting the place entered 
                String location = etPlace.getText().toString();

                if(location==null || location.equals("")){
                    Toast.makeText(getBaseContext(), "No Place is entered", Toast.LENGTH_SHORT).show();
                    return;
                }

                String url = "https://maps.googleapis.com/maps/api/geocode/json?";                  

                try {
                    // encoding special characters like space in the user input place
                    location = URLEncoder.encode(location, "utf-8");
                } catch (UnsupportedEncodingException e) {
                    e.printStackTrace();
                }

                String address = "address=" + location;

                String sensor = "sensor=false";


                // url , from where the geocoding data is fetched
                url = url + address + "&" + sensor;

                // Instantiating DownloadTask to get places from Google Geocoding service
                // in a non-ui thread
                DownloadTask downloadTask = new DownloadTask();

                // Start downloading the geocoding places
                downloadTask.execute(url);



            }
        });

    }

    private String downloadUrl(String strUrl) throws IOException{
        String data = "";
        InputStream iStream = null;
        HttpURLConnection urlConnection = null;
        try{
                URL url = new URL(strUrl);


                // Creating an http connection to communicate with url 
                urlConnection = (HttpURLConnection) url.openConnection();

                // Connecting to url 
                urlConnection.connect();

                // Reading data from url 
                iStream = urlConnection.getInputStream();

                BufferedReader br = new BufferedReader(new InputStreamReader(iStream));

                StringBuffer sb  = new StringBuffer();

                String line = "";
                while( ( line = br.readLine())  != null){
                        sb.append(line);
                }

                data = sb.toString();

                br.close();

        }catch(Exception e){
                Log.d("Exception while downloading url", e.toString());
        }finally{
                iStream.close();
                urlConnection.disconnect();
        }

        return data;

    }


     /** A class, to download Places from Geocoding webservice */
    private class DownloadTask extends AsyncTask<String, Integer, String>{

            String data = null;

            // Invoked by execute() method of this object
            @Override
            protected String doInBackground(String... url) {
                    try{                            
                            data = downloadUrl(url[0]);
                    }catch(Exception e){
                             Log.d("Background Task",e.toString());
                    }
                    return data;
            }

            // Executed after the complete execution of doInBackground() method
            @Override
            protected void onPostExecute(String result){

                    // Instantiating ParserTask which parses the json data from Geocoding webservice
                    // in a non-ui thread
                    ParserTask parserTask = new ParserTask();

                    // Start parsing the places in JSON format
                    // Invokes the "doInBackground()" method of the class ParseTask
                    parserTask.execute(result);
            }

    }

    /** A class to parse the Geocoding Places in non-ui thread */
    class ParserTask extends AsyncTask<String, Integer, List<HashMap<String,String>>>{

        JSONObject jObject;

        // Invoked by execute() method of this object
        @Override
        protected List<HashMap<String,String>> doInBackground(String... jsonData) {

            List<HashMap<String, String>> places = null;            
            GeocodeJSONParser parser = new GeocodeJSONParser();

            try{
                jObject = new JSONObject(jsonData[0]);

                /** Getting the parsed data as a an ArrayList */
                places = parser.parse(jObject);

            }catch(Exception e){
                    Log.d("Exception",e.toString());
            }
            return places;
        }

        // Executed after the complete execution of doInBackground() method
        @Override
        protected void onPostExecute(List<HashMap<String,String>> list){            

            // Clears all the existing markers          
            mMap.clear();

            for(int i=0;i<list.size();i++){

                // Creating a marker
                MarkerOptions markerOptions = new MarkerOptions();

                // Getting a place from the places list
                HashMap<String, String> hmPlace = list.get(i);

                // Getting latitude of the place
                double lat = Double.parseDouble(hmPlace.get("lat"));                

                // Getting longitude of the place
                double lng = Double.parseDouble(hmPlace.get("lng"));

                // Getting name
                String name = hmPlace.get("formatted_address");

                LatLng latLng = new LatLng(lat, lng);

                // Setting the position for the marker
                markerOptions.position(latLng);

                // Setting the title for the marker
                markerOptions.title(name);

                // Placing a marker on the touched position
                mMap.addMarker(markerOptions);    

                // Locate the first location
                if(i==0)
                    mMap.animateCamera(CameraUpdateFactory.newLatLng(latLng));
            }            
        }
    }



    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
}

GeoCodeJSONParser.java

package com.example.googlemaps;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

public class GeocodeJSONParser {

    /** Receives a JSONObject and returns a list */
    public List<HashMap<String,String>> parse(JSONObject jObject){      

        JSONArray jPlaces = null;
        try {           
            /** Retrieves all the elements in the 'places' array */
            jPlaces = jObject.getJSONArray("results");
        } catch (JSONException e) {
            e.printStackTrace();
        }
        /** Invoking getPlaces with the array of json object
         * where each json object represent a place
         */
        return getPlaces(jPlaces);
    }


    private List<HashMap<String, String>> getPlaces(JSONArray jPlaces){
        int placesCount = jPlaces.length();
        List<HashMap<String, String>> placesList = new ArrayList<HashMap<String,String>>();
        HashMap<String, String> place = null;   

        /** Taking each place, parses and adds to list object */
        for(int i=0; i<placesCount;i++){
            try {
                /** Call getPlace with place JSON object to parse the place */
                place = getPlace((JSONObject)jPlaces.get(i));
                placesList.add(place);

            } catch (JSONException e) {
                e.printStackTrace();
            }
        }

        return placesList;
    }

    /** Parsing the Place JSON object */
    private HashMap<String, String> getPlace(JSONObject jPlace){

        HashMap<String, String> place = new HashMap<String, String>();
        String formatted_address = "-NA-";      
        String lat="";
        String lng="";


        try {
            // Extracting formatted address, if available
            if(!jPlace.isNull("formatted_address")){
                formatted_address = jPlace.getString("formatted_address");
            }           

            lat = jPlace.getJSONObject("geometry").getJSONObject("location").getString("lat");
            lng = jPlace.getJSONObject("geometry").getJSONObject("location").getString("lng");          


            place.put("formatted_address", formatted_address);          
            place.put("lat", lat);
            place.put("lng", lng);


        } catch (JSONException e) {         
            e.printStackTrace();
        }       
        return place;
    }
}

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent" 

    tools:context=".MainActivity" >

    <Button 
        android:id="@+id/btn_show"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/find"
        android:layout_alignParentRight="true"                
        android:layout_alignParentTop="true" />

    <EditText 
        android:id="@+id/et_place"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:hint="@string/hint"
        android:inputType="text" 
        android:layout_toLeftOf="@id/btn_show" />

    <fragment 
        android:id="@+id/map"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_below="@id/et_place"
        class="com.google.android.gms.maps.SupportMapFragment" />


</RelativeLayout>

AndroidManifest.XML

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.googlemaps"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="17" />

    <permission
          android:name="com.example.googlemaps.permission.MAPS_RECEIVE"
          android:protectionLevel="signature"/>

    <uses-permission android:name="com.example.googlemaps.permission.MAPS_RECEIVE"/>

    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
    <uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES"/>
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>

    <uses-feature
        android:glEsVersion="0x00020000"
        android:required="true"/>    

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.googlemaps.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <meta-data
            android:name="com.google.android.maps.v2.API_KEY"
            android:value="XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"/>    


    </application>

</manifest>

我收到一个错误

Caused by: java.lang.IllegalStateException: The meta-data tag in your app's AndroidManifest.xml does not have the right value.  Expected 6111000 but found 0.  You must have the following declaration within the <application> element:     <meta-data android:name="com.google.android.gms.version" android:value="@integer/google_play_services_version" />

请帮助。

提前致谢。

Answer 1

将此添加到 list 的应用程序标签中:

<meta-data android:name="com.google.android.gms.version"
           android:value="@integer/google_play_services_version" />

下次仔细阅读错误日志。它用人类语言说出了你必须做的一切。

编辑:

使用这个 list 文件:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.googlemaps"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="17" />

    <permission
          android:name="com.example.googlemaps.permission.MAPS_RECEIVE"
          android:protectionLevel="signature"/>

    <uses-permission android:name="com.example.googlemaps.permission.MAPS_RECEIVE"/>

    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
    <uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES"/>
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>

    <uses-feature
        android:glEsVersion="0x00020000"
        android:required="true"/>    

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.googlemaps.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <meta-data
            android:name="com.google.android.gms.version"
            android:value="@integer/google_play_services_version" />

        <meta-data
            android:name="com.google.android.maps.v2.API_KEY"
            android:value="XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"/>    


    </application>

</manifest>