Android 在map上画出路线

addison_lin

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;// 连线的点   
@Override  
public void onCreate(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);// 交通图   
    // mapView.setSatellite(true);//卫星图   
    // mapView.setStreetView(true);//街景   
    MyOverlay myOverlay = new MyOverlay();   
    mapView.getOverlays().add(myOverlay);   
    mapController.setZoom(15);// 初始放大倍数   
    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);   
// 画笔   
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);// 画出路径   
    }   
}   
}  
[代码] main.xml<?xml version="1.0" encoding="utf-8"?>  
<LinearLayout xmlns:Android="http://schemas.android.com/apk/res/android"  
androidrientation="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>  
[代码] [其他]代码最后别忘了加权限 ：
<uses-permission Android:name="android.permission.INTERNET"/>
在<applacation></applacation>之间加<uses-library Android:name="com.google.android.maps" />
[代码] 绘制路线图   /**  
* 通过解析google map返回的xml，在map中画路线图  
*/  
public void drawRoute(){   
   
String url = "http://maps.google.com/maps/api/directions/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() == 200){   
   strResult = EntityUtils.toString(httpResponse.getEntity());   
  }   
} catch (Exception e) {   
  return;   
}   
   
if (-1 == strResult.indexOf("<status>OK</status>")){   
  Toast.makeText(this, "获取导航路线失败!", Toast.LENGTH_SHORT).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();   
}   


/**  
* 解析返回xml中overview_polyline的路线编码  
*   
* @param encoded  
* @return  
*/  
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;   
}