如何在异步中绘制地图中两点之间的路线任务

Question

嗨，我使用下面的代码链接来绘制地图中两点之间的路线。 http://code.google.com/p/j2memaprouteprovider/source/browse/#svn/trunk/J2MEMapRouteAndroidEx/src/org/ci/geo/route

此外，我正在使用计时器每隔30秒动态更新一次位置。它运作良好。但应用程序在20秒后会冻结。在2点之间绘制路线之后，在放大或缩小地图时，应用程序变得很慢。

是否有任何其他有效的方法来绘制2点之间的路线或在异步任务？ 任何帮助赞赏。

Answer 1

请参阅本LINK

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(); 
} 

}

MyOverLay.java

package com.agarwal.route; 

import android.content.Context; 
import android.graphics.Canvas; 
import android.graphics.Color; 
import android.graphics.Paint; 
import android.graphics.Point; 

import com.google.android.maps.GeoPoint; 
import com.google.android.maps.MapView; 
import com.google.android.maps.Overlay; 
import com.google.android.maps.Projection; 

public class MyOverLay extends Overlay 
{ 
    private GeoPoint gp1; 
    private GeoPoint gp2; 
    private int mode=0; 
    private int defaultColor; 
    Context mContext; 

    public MyOverLay(Context context,GeoPoint gp1,GeoPoint gp2,int mode) // GeoPoint is a int. (6E) 
    { 
     this.gp1 = gp1; 
     this.gp2 = gp2; 
     this.mode = mode; 
     this.mContext = context; 
     defaultColor = 999; // no defaultColor 

    } 

    public MyOverLay(GeoPoint gp1,GeoPoint gp2,int mode, int defaultColor) 
    { 
     this.gp1 = gp1; 
     this.gp2 = gp2; 
     this.mode = mode; 
     this.defaultColor = defaultColor; 
    } 
    public int getMode() 
    { 
     return mode; 
    } 

    @Override 
    public boolean draw 
    (Canvas canvas, MapView mapView, boolean shadow, long when) 
    { 
     Projection projection = mapView.getProjection(); 
     if (shadow == false) 
     { 
      Paint paint = new Paint(); 
      paint.setAntiAlias(true); 
      Point point = new Point(); 
      projection.toPixels(gp1, point); 
      // mode=1：start 
      if(mode==1) 
      { 
       if(defaultColor==999) 
        paint.setColor(Color.BLUE); 
       else 
        paint.setColor(defaultColor);     
       // start point 
      } 
      // mode=2：path 
      else if(mode==2) 
      { 
       if(defaultColor==999) 
        paint.setColor(Color.RED); 
       else 
        paint.setColor(defaultColor); 
       Point point2 = new Point(); 
       projection.toPixels(gp2, point2); 
       paint.setStrokeWidth(5); 
       paint.setAlpha(120); 
       canvas.drawLine(point.x, point.y, point2.x,point2.y, paint); 

      } 
      /* mode=3：end */ 
      else if(mode==3) 
      { 
       /* the last path */ 

       if(defaultColor==999) 
        paint.setColor(Color.GREEN); 
       else 
        paint.setColor(defaultColor); 
       Point point2 = new Point(); 
       projection.toPixels(gp2, point2); 
       paint.setStrokeWidth(5); 
       paint.setAlpha(120); 
       canvas.drawLine(point.x, point.y, point2.x,point2.y, paint); 
       /* end point */ 

      } 
     } 
     return super.draw(canvas, mapView, shadow, when); 
    } 

} 

RoutePath.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"); 
    } 
} 

您的活动，只要贴上下面几行得出的RouteMap：

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)); 

注::极品RoutePath活动和permssions在manifeast文件