Android is the way to draw a route on a map _android

The example in this article describes the way Android implements a roadmap on a map. Share to everyone for your reference. Specifically as follows:

Recently in the map to draw a road map, after a period of exploration, finally understand, in fact, quite simple, write a class to inherit overlay, and rewrite the draw method, in the draw method to draw a path. For Overaly, mark a point on the map or draw lines and the like to use Overlay,overlay equivalent to a cover, covered on the map, this cover to their own implementation so to inherit overlay.

Mapactivity.java is as follows:

Package net.blogjava.mobile.map; 
Import java.util.List; 
Import Android.app.AlertDialog; 
Import Android.graphics.Bitmap; 
Import Android.graphics.BitmapFactory; 
Import Android.graphics.Canvas; 
Import Android.graphics.Color; 
Import Android.graphics.Paint; 
Import Android.graphics.Path; 
Import Android.graphics.Point; 
Import android.location.Address; 
Import Android.location.Geocoder; 
Import Android.os.Bundle; 
Import Android.view.Menu; 
Import Com.google.android.maps.GeoPoint; 
Import com.google.android.maps.MapActivity; 
Import Com.google.android.maps.MapController; 
Import Com.google.android.maps.MapView; 
Import Com.google.android.maps.Overlay; 
Import com.google.android.maps.Projection; public class Main extends Mapactivity {private Geopoint gpoint1, Gpoint2, gpoint3;//connection point @Override public void Oncrea 
 Te (Bundle savedinstancestate) {super.oncreate (savedinstancestate); 
 Setcontentview (R.layout.main); 
 Mapview Mapview = (mapview) Findviewbyid (R.id.mapview); Mapview. Setclickable (True); 
 Mapview.setbuiltinzoomcontrols (TRUE); 
 Mapcontroller Mapcontroller = Mapview.getcontroller (); Mapview.settraffic (TRUE);//traffic map//Mapview.setsatellite (TRUE);//satellite map//Mapview.setstreetview (TRUE)//Street View Myoverlay my 
 Overlay = new Myoverlay (); 
 Mapview.getoverlays (). Add (Myoverlay);  
 Mapcontroller.setzoom (15);//initial magnification gpoint1 = new Geopoint (int) (24.477384 * 1000000), (int) (118.158216 * 1000000)); 
 Gpoint2 = new Geopoint ((int) (24.488967 * 1000000), (int) (118.144277 * 1000000)); 
 Gpoint3 = new Geopoint ((int) (24.491091 * 1000000), (int) (118.136781 * 1000000)); 
Mapcontroller.animateto (GPOINT1); 
@Override protected Boolean isroutedisplayed () {//TODO auto-generated method stub return false;  Class Myoverlay extends Overlay {@Override public void Draw (Canvas Canvas, Mapview Mapview, Boolean shadow) {// 
 TODO auto-generated Method Stub Super.draw (canvas, Mapview, shadow); 
 Brush Paint Paint = new Paint (); Paint.setcolor (color.red); 
 Paint.setdither (TRUE); 
 Paint.setstyle (Paint.Style.STROKE); 
 Paint.setstrokejoin (Paint.Join.ROUND); 
 Paint.setstrokecap (Paint.Cap.ROUND); 
 Paint.setstrokewidth (2); 
 Projection projection = Mapview.getprojection (); 
 Point P1 = new Point (); 
 Point P2 = new Point (); 
 Point p3 = new Point (); 
 Projection.topixels (Gpoint1, p1); 
 Projection.topixels (Gpoint2, p2); 
 Projection.topixels (Gpoint3, p3); 
 Path PATH = new Path (); 
 Path.moveto (p1.x, P1.Y); 
 Path.lineto (p2.x, P2.Y); 
 Path.lineto (p3.x, P3.Y);

 Canvas.drawpath (path, paint);//Draw The path}}}

Main.xml is as follows:

<?xml version= "1.0" encoding= "Utf-8"?> <linearlayout xmlns:android= 
"http://schemas.android.com/apk/" Res/android " 
 android:orientation=" vertical "android:layout_width=" fill_parent " 
 android:layout_height=" Fill_parent "> 
 <com.google.android.maps.mapview 
 android:id=" @+id/mapview "android:layout_width=" Fill_parent " 
 android:layout_height=" fill_parent " 
 android:apikey=" 0ib7kn70qp1lt216hhb-jmhj8gltie4p63o77kq "/> 
</LinearLayout>

Finally, don't forget to add a privilege:

<uses-permission android:name= "Android.permission.INTERNET"/>

Between <applacation></applacation> add <uses-library android:name= "Com.google.android.maps"/>

To draw a road map:

/** * By parsing the XML returned by Google Map, draw the roadmap in map/public void Drawroute () {String URL = "Http://maps.google.com/maps/api/directi ons/xml?origin=23.055291,113.391802 "+" &destination=23.046604,113.397510&sensor=false&mode=walking " 
 ; 
 HttpGet get = new HttpGet (URL); 
 String strresult = ""; 
  try {httpparams httpparameters = new Basichttpparams (); 
  Httpconnectionparams.setconnectiontimeout (Httpparameters, 3000); 
  HttpClient httpclient = new Defaulthttpclient (httpparameters); 
  HttpResponse HttpResponse = null; 
  HttpResponse = Httpclient.execute (get); if (Httpresponse.getstatusline (). Getstatuscode () = = Strresult = entityutils.tostring (httpresponse.getentity ()) 
  ; 
 The catch (Exception e) {return; } if ( -1 = Strresult.indexof ("<status>OK</status>")) {Toast.maketext (this, "Get the navigation route failed!", Toast.length_sho 
  RT). Show (); 
  This.finish (); 
 Return 
 int pos = Strresult.indexof ("<overview_polyline>"); pos = Strresult.indexof ("<poiNts> ", POS + 1); 
 int pos2 = Strresult.indexof ("</points>", POS); 
 strresult = strresult.substring (pos + 8, POS2); 
 List<geopoint> points = Decodepoly (strresult); 
 Myoverlay moverlay = new Myoverlay (points); 
 list<overlay> overlays = Mmapview.getoverlays (); 
 Overlays.add (Moverlay); 
 if (Points.size () >= 2) {Mmapcontroller.animateto (points.get (0)); 
 } mmapview.invalidate (); /** * resolves overview_polyline route encoding in XML * * @param encoded * @return * * Private list<geopoint> Decodepoly (stri 
 NG 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;

 }

I hope this article will help you with your Android program.