Android 如何在异步任务中绘制映射中两点之间的路由

嗨，我正在使用下面的代码链接绘制地图中两点之间的路线。

此外，我还使用计时器每30秒动态更新一次位置。它工作得很好。但应用程序在20秒后冻结。在两点之间绘制路线后，放大或缩小地图时，应用程序会变慢

在2点之间或异步任务中，是否有其他有效的方法绘制路由？？ 感谢您的帮助。

请参阅此

SharedData.java

package com.agarwal.route;



public class SharedData {

    // this is a singleton class that provides a global data share for all of the
    // activities and services in the MDWrapper application       
    private static SharedData instance = null;


    private SharedData() {
        //randomizeServers();
    }

    // data to be shared
    private String APIKEY = "";
    private double src_lat = -1;
    private double src_lng = -1;
    private double dest_lat = -1;
    private double dest_lng = -1;

    /**
     * @return the aPIKEY
     */
    public String getAPIKEY() {
        return APIKEY;
    }

    /**
     * @param aPIKEY the aPIKEY to set
     */
    public void setAPIKEY(String aPIKEY) {
        APIKEY = aPIKEY;
    }

    /**
     * @return the src_lat
     */
    public double getSrc_lat() {
        return src_lat;
    }

    /**
     * @param src_lat the src_lat to set
     */
    public void setSrc_lat(double src_lat) {
        this.src_lat = src_lat;
    }

    /**
     * @return the src_lng
     */
    public double getSrc_lng() {
        return src_lng;
    }

    /**
     * @param src_lng the src_lng to set
     */
    public void setSrc_lng(double src_lng) {
        this.src_lng = src_lng;
    }

    /**
     * @return the dest_lat
     */
    public double getDest_lat() {
        return dest_lat;
    }

    /**
     * @param dest_lat the dest_lat to set
     */
    public void setDest_lat(double dest_lat) {
        this.dest_lat = dest_lat;
    }

    /**
     * @return the dest_lng
     */
    public double getDest_lng() {
        return dest_lng;
    }

    /**
     * @param dest_lng the dest_lng to set
     */
    public void setDest_lng(double dest_lng) {
        this.dest_lng = dest_lng;
    }

    public static SharedData getInstance() {
        if (null == instance) {
            instance = new SharedData();
        }

        return instance;
    }

}

CustomItemizedOverlay.java

package com.agarwal.route;
import java.util.ArrayList;

import android.graphics.drawable.Drawable;

import com.google.android.maps.ItemizedOverlay;
import com.google.android.maps.OverlayItem;

public class CustomItemizedOverlay extends ItemizedOverlay<OverlayItem> {

private final ArrayList<OverlayItem> mapOverlays = new ArrayList<OverlayItem>();


public CustomItemizedOverlay(Drawable defaultMarker) {
    super(boundCenterBottom(defaultMarker));
}

@Override
protected OverlayItem createItem(int i) {
    return mapOverlays.get(i);
}

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

public void addOverlay(OverlayItem overlay) {
    mapOverlays.add(overlay);
    this.populate();
}

java

package com.agarwal.route;

import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

import android.app.AlertDialog;
import android.app.ProgressDialog;
import android.content.DialogInterface;
import android.graphics.Color;
import android.graphics.drawable.Drawable;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;

import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapView;
import com.google.android.maps.Overlay;
import com.google.android.maps.OverlayItem;


public class RoutePath extends MapActivity {
    /** Called when the activity is first created. */
    MapView mapView;
    private RoutePath _activity;
    GeoPoint srcGeoPoint,destGeoPoint;
    private static List<Overlay> mOverlays;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        SharedData data = SharedData.getInstance();
        mapView = new MapView(this,data.getAPIKEY());
        mapView.setClickable(true);       
        setContentView(mapView);
        _activity = this;
        double src_lat = data.getSrc_lat();
        double src_long = data.getSrc_lng();
        double dest_lat = data.getDest_lat();
        double dest_long = data.getDest_lng();

        if(src_lat == -1 || src_long == -1 || dest_lat == -1 || dest_long == -1){
            showAlert("Please enter source and destination points");
        }else{

            srcGeoPoint = new GeoPoint((int) (src_lat * 1E6),(int) (src_long * 1E6));
            destGeoPoint = new GeoPoint((int) (dest_lat * 1E6),(int) (dest_long * 1E6));

            List<Overlay> mapOverlays = mapView.getOverlays();
            Drawable srcdrawable = this.getResources().getDrawable(R.drawable.pin_green);
            //CustomItemizedOverlay srcitemizedOverlay = new CustomItemizedOverlay(getDrawable("com/agarwal/route/pin_green.png"));
            OverlayItem srcoverlayitem = new OverlayItem(srcGeoPoint, "Hello!", "This is your Location.");

            Drawable destdrawable = this.getResources().getDrawable(R.drawable.pin_red);
           // CustomItemizedOverlay destitemizedOverlay = new CustomItemizedOverlay(getDrawable("com/agarwal/route/pin_red.png"));
            OverlayItem destoverlayitem = new OverlayItem(destGeoPoint, "Hello!", "This is dest Location.");

            srcitemizedOverlay.addOverlay(srcoverlayitem);
            destitemizedOverlay.addOverlay(destoverlayitem);

            mapOverlays.add(srcitemizedOverlay);
            mapOverlays.add(destitemizedOverlay);

            connectAsyncTask _connectAsyncTask = new connectAsyncTask();
            _connectAsyncTask.execute();         
            mapView.setBuiltInZoomControls(true);
            mapView.displayZoomControls(true);
            mOverlays = mapView.getOverlays();
            mapView.getController().animateTo(srcGeoPoint);
            mapView.getController().setZoom(12);
        }
    }
    @Override
    protected boolean isRouteDisplayed() {
        // TODO Auto-generated method stub
        return false;
    }

    private class connectAsyncTask extends AsyncTask<Void, Void, Void>{
        private ProgressDialog progressDialog;
        @Override
        protected void onPreExecute() {
            // TODO Auto-generated method stub
            super.onPreExecute();
            progressDialog = new ProgressDialog(_activity);
            progressDialog.setMessage("Fetching route, Please wait...");
            progressDialog.setIndeterminate(true);
            progressDialog.show();
        }
        @Override
        protected Void doInBackground(Void... params) {
            // TODO Auto-generated method stub
            fetchData();
            return null;
        }
        @Override
        protected void onPostExecute(Void result) {
            // TODO Auto-generated method stub
            super.onPostExecute(result);           
            if(doc!=null){
                Overlay ol = new MyOverLay(_activity,srcGeoPoint,srcGeoPoint,1);
                mOverlays.add(ol);
                NodeList _nodelist = doc.getElementsByTagName("status");
                Node node1 = _nodelist.item(0);
                String _status1  = node1.getChildNodes().item(0).getNodeValue();
                if(_status1.equalsIgnoreCase("OK")){
                    NodeList _nodelist_path = doc.getElementsByTagName("overview_polyline");
                    Node node_path = _nodelist_path.item(0);
                    Element _status_path = (Element)node_path;
                    NodeList _nodelist_destination_path = _status_path.getElementsByTagName("points");
                    Node _nodelist_dest = _nodelist_destination_path.item(0);
                    String _path  = _nodelist_dest.getChildNodes().item(0).getNodeValue();
                    List<GeoPoint> _geopoints = decodePoly(_path);
                    GeoPoint gp1;
                    GeoPoint gp2;
                    gp2 = _geopoints.get(0);
                    Log.d("_geopoints","::"+_geopoints.size());
                    for(int i=1;i<_geopoints.size();i++) // the last one would be crash
                    {

                        gp1 = gp2;
                        gp2 = _geopoints.get(i);
                        Overlay ol1 = new MyOverLay(gp1,gp2,2,Color.BLUE);
                        mOverlays.add(ol1);
                    }
                    Overlay ol2 = new MyOverLay(_activity,destGeoPoint,destGeoPoint,3);
                    mOverlays.add(ol2);

                    progressDialog.dismiss();
                }else{
                    showAlert("Unable to find the route");
                }

                Overlay ol2 = new MyOverLay(_activity,destGeoPoint,destGeoPoint,3);
                mOverlays.add(ol2);
                progressDialog.dismiss();
                mapView.scrollBy(-1,-1);
                mapView.scrollBy(1,1);
            }else{
                showAlert("Unable to find the route");
            }

        }

    }
    Document doc = null;
    private void fetchData()
    {
        StringBuilder urlString = new StringBuilder();
        urlString.append("http://maps.google.com/maps/api/directions/xml?origin=");
        urlString.append( Double.toString((double)srcGeoPoint.getLatitudeE6()/1.0E6 ));
        urlString.append(",");
        urlString.append( Double.toString((double)srcGeoPoint.getLongitudeE6()/1.0E6 ));
        urlString.append("&destination=");//to
        urlString.append( Double.toString((double)destGeoPoint.getLatitudeE6()/1.0E6 ));
        urlString.append(",");
        urlString.append( Double.toString((double)destGeoPoint.getLongitudeE6()/1.0E6 ));
        urlString.append("&sensor=true&mode=driving");    
        Log.d("url","::"+urlString.toString());
        HttpURLConnection urlConnection= null;
        URL url = null;
        try
        {
            url = new URL(urlString.toString());
            urlConnection=(HttpURLConnection)url.openConnection();
            urlConnection.setRequestMethod("GET");
            urlConnection.setDoOutput(true);
            urlConnection.setDoInput(true);
            urlConnection.connect();
            DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
            DocumentBuilder db = dbf.newDocumentBuilder();
            doc = (Document) db.parse(urlConnection.getInputStream());//Util.XMLfromString(response);
        }catch (MalformedURLException e){
            e.printStackTrace();
        }catch (IOException e){
            e.printStackTrace();
        }catch (ParserConfigurationException e){
            e.printStackTrace();
        }
        catch (SAXException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    private List<GeoPoint> decodePoly(String encoded) {

        List<GeoPoint> poly = new ArrayList<GeoPoint>();
        int index = 0, len = encoded.length();
        int lat = 0, lng = 0;

        while (index < len) {
            int b, shift = 0, result = 0;
            do {
                b = encoded.charAt(index++) - 63;
                result |= (b & 0x1f) << shift;
                shift += 5;
            } while (b >= 0x20);
            int dlat = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
            lat += dlat;

            shift = 0;
            result = 0;
            do {
                b = encoded.charAt(index++) - 63;
                result |= (b & 0x1f) << shift;
                shift += 5;
            } while (b >= 0x20);
            int dlng = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
            lng += dlng;

            GeoPoint p = new GeoPoint((int) (((double) lat / 1E5) * 1E6),
                    (int) (((double) lng / 1E5) * 1E6));
            poly.add(p);
        }

        return poly;
    }
    private void showAlert(String message){
        AlertDialog.Builder alert = new AlertDialog.Builder(_activity);
        alert.setTitle("Error");
        alert.setCancelable(false);
        alert.setMessage(message);
        alert.setPositiveButton("Ok",new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                // TODO Auto-generated method stub

            }
        });
        alert.show();
    }
    private Drawable getDrawable(String fileName){
        return Drawable.createFromStream(_activity.getClass().getClassLoader().getResourceAsStream(fileName), "pin");
    }
}

---

注意：需要在Manifeat文件中设置路径活动和权限

您的目标是在两个地质点之间绘制路线图，并且我想显示两点之间的距离请参阅以下链接，[draw path][1][1]：java SharedData中的apikey与答案底部的data.setAPIKEY（）相同吗？。。。

package com.agarwal.route;

import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

import android.app.AlertDialog;
import android.app.ProgressDialog;
import android.content.DialogInterface;
import android.graphics.Color;
import android.graphics.drawable.Drawable;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;

import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapView;
import com.google.android.maps.Overlay;
import com.google.android.maps.OverlayItem;


public class RoutePath extends MapActivity {
    /** Called when the activity is first created. */
    MapView mapView;
    private RoutePath _activity;
    GeoPoint srcGeoPoint,destGeoPoint;
    private static List<Overlay> mOverlays;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        SharedData data = SharedData.getInstance();
        mapView = new MapView(this,data.getAPIKEY());
        mapView.setClickable(true);       
        setContentView(mapView);
        _activity = this;
        double src_lat = data.getSrc_lat();
        double src_long = data.getSrc_lng();
        double dest_lat = data.getDest_lat();
        double dest_long = data.getDest_lng();

        if(src_lat == -1 || src_long == -1 || dest_lat == -1 || dest_long == -1){
            showAlert("Please enter source and destination points");
        }else{

            srcGeoPoint = new GeoPoint((int) (src_lat * 1E6),(int) (src_long * 1E6));
            destGeoPoint = new GeoPoint((int) (dest_lat * 1E6),(int) (dest_long * 1E6));

            List<Overlay> mapOverlays = mapView.getOverlays();
            Drawable srcdrawable = this.getResources().getDrawable(R.drawable.pin_green);
            //CustomItemizedOverlay srcitemizedOverlay = new CustomItemizedOverlay(getDrawable("com/agarwal/route/pin_green.png"));
            OverlayItem srcoverlayitem = new OverlayItem(srcGeoPoint, "Hello!", "This is your Location.");

            Drawable destdrawable = this.getResources().getDrawable(R.drawable.pin_red);
           // CustomItemizedOverlay destitemizedOverlay = new CustomItemizedOverlay(getDrawable("com/agarwal/route/pin_red.png"));
            OverlayItem destoverlayitem = new OverlayItem(destGeoPoint, "Hello!", "This is dest Location.");

            srcitemizedOverlay.addOverlay(srcoverlayitem);
            destitemizedOverlay.addOverlay(destoverlayitem);

            mapOverlays.add(srcitemizedOverlay);
            mapOverlays.add(destitemizedOverlay);

            connectAsyncTask _connectAsyncTask = new connectAsyncTask();
            _connectAsyncTask.execute();         
            mapView.setBuiltInZoomControls(true);
            mapView.displayZoomControls(true);
            mOverlays = mapView.getOverlays();
            mapView.getController().animateTo(srcGeoPoint);
            mapView.getController().setZoom(12);
        }
    }
    @Override
    protected boolean isRouteDisplayed() {
        // TODO Auto-generated method stub
        return false;
    }

    private class connectAsyncTask extends AsyncTask<Void, Void, Void>{
        private ProgressDialog progressDialog;
        @Override
        protected void onPreExecute() {
            // TODO Auto-generated method stub
            super.onPreExecute();
            progressDialog = new ProgressDialog(_activity);
            progressDialog.setMessage("Fetching route, Please wait...");
            progressDialog.setIndeterminate(true);
            progressDialog.show();
        }
        @Override
        protected Void doInBackground(Void... params) {
            // TODO Auto-generated method stub
            fetchData();
            return null;
        }
        @Override
        protected void onPostExecute(Void result) {
            // TODO Auto-generated method stub
            super.onPostExecute(result);           
            if(doc!=null){
                Overlay ol = new MyOverLay(_activity,srcGeoPoint,srcGeoPoint,1);
                mOverlays.add(ol);
                NodeList _nodelist = doc.getElementsByTagName("status");
                Node node1 = _nodelist.item(0);
                String _status1  = node1.getChildNodes().item(0).getNodeValue();
                if(_status1.equalsIgnoreCase("OK")){
                    NodeList _nodelist_path = doc.getElementsByTagName("overview_polyline");
                    Node node_path = _nodelist_path.item(0);
                    Element _status_path = (Element)node_path;
                    NodeList _nodelist_destination_path = _status_path.getElementsByTagName("points");
                    Node _nodelist_dest = _nodelist_destination_path.item(0);
                    String _path  = _nodelist_dest.getChildNodes().item(0).getNodeValue();
                    List<GeoPoint> _geopoints = decodePoly(_path);
                    GeoPoint gp1;
                    GeoPoint gp2;
                    gp2 = _geopoints.get(0);
                    Log.d("_geopoints","::"+_geopoints.size());
                    for(int i=1;i<_geopoints.size();i++) // the last one would be crash
                    {

                        gp1 = gp2;
                        gp2 = _geopoints.get(i);
                        Overlay ol1 = new MyOverLay(gp1,gp2,2,Color.BLUE);
                        mOverlays.add(ol1);
                    }
                    Overlay ol2 = new MyOverLay(_activity,destGeoPoint,destGeoPoint,3);
                    mOverlays.add(ol2);

                    progressDialog.dismiss();
                }else{
                    showAlert("Unable to find the route");
                }

                Overlay ol2 = new MyOverLay(_activity,destGeoPoint,destGeoPoint,3);
                mOverlays.add(ol2);
                progressDialog.dismiss();
                mapView.scrollBy(-1,-1);
                mapView.scrollBy(1,1);
            }else{
                showAlert("Unable to find the route");
            }

        }

    }
    Document doc = null;
    private void fetchData()
    {
        StringBuilder urlString = new StringBuilder();
        urlString.append("http://maps.google.com/maps/api/directions/xml?origin=");
        urlString.append( Double.toString((double)srcGeoPoint.getLatitudeE6()/1.0E6 ));
        urlString.append(",");
        urlString.append( Double.toString((double)srcGeoPoint.getLongitudeE6()/1.0E6 ));
        urlString.append("&destination=");//to
        urlString.append( Double.toString((double)destGeoPoint.getLatitudeE6()/1.0E6 ));
        urlString.append(",");
        urlString.append( Double.toString((double)destGeoPoint.getLongitudeE6()/1.0E6 ));
        urlString.append("&sensor=true&mode=driving");    
        Log.d("url","::"+urlString.toString());
        HttpURLConnection urlConnection= null;
        URL url = null;
        try
        {
            url = new URL(urlString.toString());
            urlConnection=(HttpURLConnection)url.openConnection();
            urlConnection.setRequestMethod("GET");
            urlConnection.setDoOutput(true);
            urlConnection.setDoInput(true);
            urlConnection.connect();
            DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
            DocumentBuilder db = dbf.newDocumentBuilder();
            doc = (Document) db.parse(urlConnection.getInputStream());//Util.XMLfromString(response);
        }catch (MalformedURLException e){
            e.printStackTrace();
        }catch (IOException e){
            e.printStackTrace();
        }catch (ParserConfigurationException e){
            e.printStackTrace();
        }
        catch (SAXException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    private List<GeoPoint> decodePoly(String encoded) {

        List<GeoPoint> poly = new ArrayList<GeoPoint>();
        int index = 0, len = encoded.length();
        int lat = 0, lng = 0;

        while (index < len) {
            int b, shift = 0, result = 0;
            do {
                b = encoded.charAt(index++) - 63;
                result |= (b & 0x1f) << shift;
                shift += 5;
            } while (b >= 0x20);
            int dlat = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
            lat += dlat;

            shift = 0;
            result = 0;
            do {
                b = encoded.charAt(index++) - 63;
                result |= (b & 0x1f) << shift;
                shift += 5;
            } while (b >= 0x20);
            int dlng = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
            lng += dlng;

            GeoPoint p = new GeoPoint((int) (((double) lat / 1E5) * 1E6),
                    (int) (((double) lng / 1E5) * 1E6));
            poly.add(p);
        }

        return poly;
    }
    private void showAlert(String message){
        AlertDialog.Builder alert = new AlertDialog.Builder(_activity);
        alert.setTitle("Error");
        alert.setCancelable(false);
        alert.setMessage(message);
        alert.setPositiveButton("Ok",new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                // TODO Auto-generated method stub

            }
        });
        alert.show();
    }
    private Drawable getDrawable(String fileName){
        return Drawable.createFromStream(_activity.getClass().getClassLoader().getResourceAsStream(fileName), "pin");
    }
}

SharedData data = SharedData.getInstance();
data.setAPIKEY("0RUTLH7cqd6yrZ0FdS0NfQMO3lioiCbnH-BpNQQ");
data.setSrc_lat(17);
data.setSrc_lng(78);
data.setDest_lat(18);
data.setDest_lng(77);
startActivity(new Intent(YourActivity.this,RoutePath.class));