0

我正在努力将谷歌地图集成到我的应用程序中。我以某种方式设法显示带有用户位置和附近位置的地图，但位置没有更新......我已经多次查看代码但没有找到一个不正确的命令..请帮我解决它..

NearbyPlaces活动 -

package com.example.travelplanner;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.StatusLine;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.MapFragment;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
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 android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.util.Log;
import android.view.Menu;
import android.widget.Toast;

/*
 * MyMapActivity class forms part of Map application
 * in Mobiletuts+ tutorial series:
 * Using Google Maps and Google Places in Android Apps
 * 
 * This version of the class is for the final part of the series.
 * 
 * Sue Smith
 * March/ April 2013
 */
public class NearbyPlacesActivity extends Activity implements LocationListener {

    //instance variables for Marker icon drawable resources
    private int userIcon, foodIcon, drinkIcon, shopIcon, otherIcon;

    //the map
    private GoogleMap theMap;

    //location manager
    private LocationManager locMan;

    //user marker
    private Marker userMarker;

    //places of interest
    private Marker[] placeMarkers;
    //max
    private final int MAX_PLACES = 20;//most returned from google
    //marker options
    private MarkerOptions[] places;

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

        //get drawable IDs
        userIcon = R.drawable.yellow_point;
        foodIcon = R.drawable.red_point;
        drinkIcon = R.drawable.blue_point;
        shopIcon = R.drawable.green_point;
        otherIcon = R.drawable.purple_point;

        //find out if we already have it
        if(theMap==null){
            //get the map
            theMap = ((MapFragment)getFragmentManager().findFragmentById(R.id.the_map)).getMap();
            //check in case map/ Google Play services not available
            if(theMap!=null){
                //ok - proceed
                theMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);
                //create marker array
                placeMarkers = new Marker[MAX_PLACES];
                //update location
                updatePlaces();
            }

        }
    }

    //location listener functions

    @Override
    public void onLocationChanged(Location location) {
        Log.v("MyMapActivity", "location changed");
        updatePlaces();
    }
    @Override
    public void onProviderDisabled(String provider){
        Log.v("MyMapActivity", "provider disabled");
    }
    @Override
    public void onProviderEnabled(String provider) {
        Log.v("MyMapActivity", "provider enabled");
    }
    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {
        Log.v("MyMapActivity", "status changed");
    }

    /*
     * update the place markers
     */
    private void updatePlaces(){
        //get location manager
        locMan = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
        //get last location
        Location lastLoc = locMan.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
        double lat = lastLoc.getLatitude();
        double lng = lastLoc.getLongitude();
        Toast.makeText(getApplicationContext(), lat+","+lng, Toast.LENGTH_LONG).show();
        //create LatLng
        LatLng lastLatLng = new LatLng(lat, lng);

        //remove any existing marker
        if(userMarker!=null) userMarker.remove();
        //create and set marker properties
        userMarker = theMap.addMarker(new MarkerOptions()
        .position(lastLatLng)
        .title("You are here")
        .icon(BitmapDescriptorFactory.fromResource(userIcon))
        .snippet("Your last recorded location"));
        //move to location
        theMap.animateCamera(CameraUpdateFactory.newLatLng(lastLatLng), 3000, null);

        //build places query string
        String placesSearchStr = "https://maps.googleapis.com/maps/api/place/nearbysearch/" +
                "json?location="+lat+","+lng+
                "&radius=7000&sensor=true" +
                "&types=food|bar|movie_theater|museum|bank"+
                "&key=AIzaSyBqDgqbxFenOtooTivY5YSsJ2JrwBK42hw";//ADD KEY

        //execute query
        new GetPlaces().execute(placesSearchStr);       
        locMan.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 30000, 100, this);
    }

    private class GetPlaces extends AsyncTask<String, Void, String> {
        @Override
        protected String doInBackground(String... placesURL) {
            //fetch places

            //build result as string
            StringBuilder placesBuilder = new StringBuilder();
            //process search parameter string(s)
            for (String placeSearchURL : placesURL) {
                HttpClient placesClient = new DefaultHttpClient();
                try {
                    //try to fetch the data

                    //HTTP Get receives URL string
                    HttpGet placesGet = new HttpGet(placeSearchURL);
                    //execute GET with Client - return response
                    HttpResponse placesResponse = placesClient.execute(placesGet);
                    //check response status
                    StatusLine placeSearchStatus = placesResponse.getStatusLine();
                    //only carry on if response is OK
                    if (placeSearchStatus.getStatusCode() == 200) {
                        //get response entity
                        HttpEntity placesEntity = placesResponse.getEntity();
                        //get input stream setup
                        InputStream placesContent = placesEntity.getContent();
                        //create reader
                        InputStreamReader placesInput = new InputStreamReader(placesContent);
                        //use buffered reader to process
                        BufferedReader placesReader = new BufferedReader(placesInput);
                        //read a line at a time, append to string builder
                        String lineIn;
                        while ((lineIn = placesReader.readLine()) != null) {
                            placesBuilder.append(lineIn);
                        }
                    }
                }
                catch(Exception e){ 
                    e.printStackTrace(); 
                }
            }
            return placesBuilder.toString();
        }
        //process data retrieved from doInBackground
        protected void onPostExecute(String result) {
            //parse place data returned from Google Places
            //remove existing markers
            if(placeMarkers!=null){
                for(int pm=0; pm<placeMarkers.length; pm++){
                    if(placeMarkers[pm]!=null)
                        placeMarkers[pm].remove();
                }
            }
            try {
                //parse JSON

                //create JSONObject, pass stinrg returned from doInBackground
                JSONObject resultObject = new JSONObject(result);
                //get "results" array
                JSONArray placesArray = resultObject.getJSONArray("results");
                //marker options for each place returned
                places = new MarkerOptions[placesArray.length()];
                //loop through places
                for (int p=0; p<placesArray.length(); p++) {
                    //parse each place
                    //if any values are missing we won't show the marker
                    boolean missingValue=false;
                    LatLng placeLL=null;
                    String placeName="";
                    String vicinity="";
                    int currIcon = otherIcon;
                    try{
                        //attempt to retrieve place data values
                        missingValue=false;
                        //get place at this index
                        JSONObject placeObject = placesArray.getJSONObject(p);
                        //get location section
                        JSONObject loc = placeObject.getJSONObject("geometry")
                                .getJSONObject("location");
                        //read lat lng
                        placeLL = new LatLng(Double.valueOf(loc.getString("lat")), 
                                Double.valueOf(loc.getString("lng")));  
                        //get types
                        JSONArray types = placeObject.getJSONArray("types");
                        //loop through types
                        for(int t=0; t<types.length(); t++){
                            //what type is it
                            String thisType=types.get(t).toString();
                            //check for particular types - set icons
                            if(thisType.contains("food")){
                                currIcon = foodIcon;
                                break;
                            }
                            else if(thisType.contains("bar")){
                                currIcon = drinkIcon;
                                break;
                            }
                            else if(thisType.contains("movie_theater")){
                                currIcon = shopIcon;
                                break;
                            }
                        }
                        //vicinity
                        vicinity = placeObject.getString("vicinity");
                        //name
                        placeName = placeObject.getString("name");
                    }
                    catch(JSONException jse){
                        Log.v("PLACES", "missing value");
                        missingValue=true;
                        jse.printStackTrace();
                    }
                    //if values missing we don't display
                    if(missingValue)    places[p]=null;
                    else
                        places[p]=new MarkerOptions()
                    .position(placeLL)
                    .title(placeName)
                    .icon(BitmapDescriptorFactory.fromResource(currIcon))
                    .snippet(vicinity);
                }
            }
            catch (Exception e) {
                e.printStackTrace();
            }
            if(places!=null && placeMarkers!=null){
                for(int p=0; p<places.length && p<placeMarkers.length; p++){
                    //will be null if a value was missing
                    if(places[p]!=null)
                        placeMarkers[p]=theMap.addMarker(places[p]);

            }

        }
    }   
}
    @Override
    protected void onResume() {
        super.onResume();
        if(theMap!=null){
            locMan.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 30000, 100, this);
        }
    }

    @Override
    protected void onPause() {
        super.onPause();
        if(theMap!=null){
            locMan.removeUpdates(this);
        }
    }
}

logcat中没有错误。根据我的担心，清单是准确的……API 密钥也是正确的……

我还想知道一件事....如何通过单击先前活动的按钮来显示特定城市的地图..例如：在活动一中，我在edittext中键入了纽约并单击了按钮并打开了活动两个包含地图并指向纽约市...我还想用不同的标记显示纽约的旅游景点....有人可以告诉我一个方法或 tut 吗...提前谢谢

这是根据您的指导修改后的代码..

package com.example.travelplanner;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URLEncoder;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.StatusLine;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.MapFragment;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
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 android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.util.Log;
import android.view.Menu;
import android.widget.Toast;

/*
 * MyMapActivity class forms part of Map application
 * in Mobiletuts+ tutorial series:
 * Using Google Maps and Google Places in Android Apps
 * 
 * This version of the class is for the final part of the series.
 * 
 * Sue Smith
 * March/ April 2013
 */
public class NearbyPlacesActivity extends Activity implements LocationListener {

    //instance variables for Marker icon drawable resources
    private int userIcon, foodIcon, drinkIcon, shopIcon, otherIcon;

    //the map
    private GoogleMap theMap;

    //location manager
    private LocationManager locMan;

    //user marker
    private Marker userMarker;

    //places of interest
    private Marker[] placeMarkers;
    //max
    private final int MAX_PLACES = 20;//most returned from google
    //marker options
    private MarkerOptions[] places;

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

        //get drawable IDs
        userIcon = R.drawable.yellow_point;
        foodIcon = R.drawable.red_point;
        drinkIcon = R.drawable.blue_point;
        shopIcon = R.drawable.green_point;
        otherIcon = R.drawable.purple_point;

        //find out if we already have it
        if(theMap==null){
            //get the map
            theMap = ((MapFragment)getFragmentManager().findFragmentById(R.id.the_map)).getMap();
            //check in case map/ Google Play services not available
            if(theMap!=null){
                //ok - proceed
                theMap.setMapType(GoogleMap.MAP_TYPE_NORMAL);
                //create marker array
                placeMarkers = new Marker[MAX_PLACES];

            }

        }
    }

    //location listener functions

    @Override
    public void onLocationChanged(Location location) {
        Log.v("MyMapActivity", "location changed");
        updatePlaces(location);
    }
    @Override
    public void onProviderDisabled(String provider){
        Log.v("MyMapActivity", "provider disabled");
    }
    @Override
    public void onProviderEnabled(String provider) {
        Log.v("MyMapActivity", "provider enabled");
    }
    @Override
    public void onStatusChanged(String provider, int status, Bundle extras) {
        Log.v("MyMapActivity", "status changed");
    }

    /*
     * update the place markers
     */
    private void updatePlaces(Location givenlocation){
        //get location manager
        double lat = givenlocation.getLatitude();
        double lng = givenlocation.getLongitude();
        Toast.makeText(getApplicationContext(), lat+","+lng, Toast.LENGTH_LONG).show();
        //create LatLng
        LatLng lastLatLng = new LatLng(lat, lng);

        //remove any existing marker
        if(userMarker!=null) userMarker.remove();
        //create and set marker properties
        userMarker = theMap.addMarker(new MarkerOptions()
        .position(lastLatLng)
        .title("You are here")
        .icon(BitmapDescriptorFactory.fromResource(userIcon))
        .snippet("Your last recorded location"));
        //move to location
        theMap.animateCamera(CameraUpdateFactory.newLatLng(lastLatLng), 3000, null);

        //build places query string
        @SuppressWarnings("deprecation")
        String encodedstr = URLEncoder.encode("food|bar|movie_theater|museum|bank");
        String placesSearchStr = "https://maps.googleapis.com/maps/api/place/nearbysearch/" +
                "json?location="+lat+","+lng+
                "&radius=7000&sensor=true"+
                "&types="+encodedstr+
                "&key=AIzaSyBqDgqbxFenOtooTivY5YSsJ2JrwBK42hw";//ADD KEY

        //execute query
        new GetPlaces().execute(placesSearchStr);       
        locMan.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 30000, 100, this);
    }

    private class GetPlaces extends AsyncTask<String, Void, String> {
        @Override
        protected String doInBackground(String... placesURL) {
            //fetch places

            //build result as string
            StringBuilder placesBuilder = new StringBuilder();
            //process search parameter string(s)
            for (String placeSearchURL : placesURL) {
                HttpClient placesClient = new DefaultHttpClient();
                try {
                    //try to fetch the data

                    //HTTP Get receives URL string
                    HttpGet placesGet = new HttpGet(placeSearchURL);
                    //execute GET with Client - return response
                    HttpResponse placesResponse = placesClient.execute(placesGet);
                    //check response status
                    StatusLine placeSearchStatus = placesResponse.getStatusLine();
                    //only carry on if response is OK
                    if (placeSearchStatus.getStatusCode() == 200) {
                        //get response entity
                        HttpEntity placesEntity = placesResponse.getEntity();
                        //get input stream setup
                        InputStream placesContent = placesEntity.getContent();
                        //create reader
                        InputStreamReader placesInput = new InputStreamReader(placesContent);
                        //use buffered reader to process
                        BufferedReader placesReader = new BufferedReader(placesInput);
                        //read a line at a time, append to string builder
                        String lineIn;
                        while ((lineIn = placesReader.readLine()) != null) {
                            placesBuilder.append(lineIn);
                        }
                    }
                }
                catch(Exception e){ 
                    e.printStackTrace(); 
                }
            }
            return placesBuilder.toString();
        }
        //process data retrieved from doInBackground
        protected void onPostExecute(String result) {
            //parse place data returned from Google Places
            //remove existing markers
            if(placeMarkers!=null){
                for(int pm=0; pm<placeMarkers.length; pm++){
                    if(placeMarkers[pm]!=null)
                        placeMarkers[pm].remove();
                }
            }
            try {
                //parse JSON

                //create JSONObject, pass stinrg returned from doInBackground
                JSONObject resultObject = new JSONObject(result);
                //get "results" array
                JSONArray placesArray = resultObject.getJSONArray("results");
                //marker options for each place returned
                places = new MarkerOptions[placesArray.length()];
                //loop through places
                for (int p=0; p<placesArray.length(); p++) {
                    //parse each place
                    //if any values are missing we won't show the marker
                    boolean missingValue=false;
                    LatLng placeLL=null;
                    String placeName="";
                    String vicinity="";
                    int currIcon = otherIcon;
                    try{
                        //attempt to retrieve place data values
                        missingValue=false;
                        //get place at this index
                        JSONObject placeObject = placesArray.getJSONObject(p);
                        //get location section
                        JSONObject loc = placeObject.getJSONObject("geometry")
                                .getJSONObject("location");
                        //read lat lng
                        placeLL = new LatLng(Double.valueOf(loc.getString("lat")), 
                                Double.valueOf(loc.getString("lng")));  
                        //get types
                        JSONArray types = placeObject.getJSONArray("types");
                        //loop through types
                        for(int t=0; t<types.length(); t++){
                            //what type is it
                            String thisType=types.get(t).toString();
                            //check for particular types - set icons
                            if(thisType.contains("food")){
                                currIcon = foodIcon;
                                break;
                            }
                            else if(thisType.contains("bar")){
                                currIcon = drinkIcon;
                                break;
                            }
                            else if(thisType.contains("movie_theater")){
                                currIcon = shopIcon;
                                break;
                            }
                        }
                        //vicinity
                        vicinity = placeObject.getString("vicinity");
                        //name
                        placeName = placeObject.getString("name");
                    }
                    catch(JSONException jse){
                        Log.v("PLACES", "missing value");
                        missingValue=true;
                        jse.printStackTrace();
                    }
                    //if values missing we don't display
                    if(missingValue)    places[p]=null;
                    else
                        places[p]=new MarkerOptions()
                    .position(placeLL)
                    .title(placeName)
                    .icon(BitmapDescriptorFactory.fromResource(currIcon))
                    .snippet(vicinity);
                }
            }
            catch (Exception e) {
                e.printStackTrace();
            }
            if(places!=null && placeMarkers!=null){
                for(int p=0; p<places.length && p<placeMarkers.length; p++){
                    //will be null if a value was missing
                    if(places[p]!=null)
                        placeMarkers[p]=theMap.addMarker(places[p]);

            }

        }
    }   
}
    @Override
    protected void onResume() {
        super.onResume();
        if(theMap!=null){
            //get location manager
        locMan = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
        //get last location
        Location lastLoc = locMan.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
        locMan.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 30000, 100, this);
        updatePlaces(lastLoc);
        }
    }

    @Override
    protected void onPause() {
        super.onPause();
        if(theMap!=null){
            locMan.removeUpdates(this);
        }
    }
}

请检查一下...它没有更新我的位置...虽然它显示附近的位置..提前谢谢

4

1 回答 1

0

问题似乎是，每当您接到电话时onLocationChanged()，您都在调用updatePlaces()重新初始化位置管理器的方法。该行将locMan = (LocationManager)getSystemService(Context.LOCATION_SERVICE);返回位置管理器的新实例，然后您正在调用getLastKnownLocation这个新的位置管理器。您getLastKnownLocation必须返回过时的位置信息，因此您可能看不到任何更新。您最终使用此位置而不是更改侦听器返回的新位置。您可以初始化这些并在 onResume 中调用 updatePlaces，如下所示：

@Override
    protected void onResume() {
        super.onResume();
        if(theMap!=null){
            //get location manager
        locMan = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
        //get last location
        Location lastLoc = locMan.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
        locMan.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 30000, 100, this);
        updatePlaces(lastLoc)
        }
    }

修改位置已更改：

@Override
    public void onLocationChanged(Location location) {
        Log.v("MyMapActivity", "location changed");
        updatePlaces(location);
    }

修改更新地点：

private void updatePlaces(Location givenlocation){

        double lat = givenlocation.getLatitude();
        double lng = givenlocation.getLongitude();
        Toast.makeText(getApplicationContext(), lat+","+lng, Toast.LENGTH_LONG).show();
        //create LatLng
        LatLng lastLatLng = new LatLng(lat, lng);

    *****Call further steps using the above location ******

目前您正在使用作为 android 平台一部分的位置 API。我还建议您可以迁移到新的 Google 位置服务 API，它是 Google Play 服务的一部分，因为它以改进的方式处理位置更新和电池节省。

于 2013-07-04T08:24:16.257 回答