问题
Can i mark two points on the google maps in my application and then calculate the direction on the map as well as turn by turn navigation ?
回答1:
No the Map Activity doesn't provide such a feature. You have to request it via the Google Maps Web API.
回答2:
I am create an application which are used to get the driving direction between two points in the map
Step be step
step1 First create a class MyOverlay.java which are used to draw a path
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Point;
import android.graphics.RectF;
import android.util.Log;
//import android.util.Log;
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 mRadius=6;
private int mode=0;
private int defaultColor;
private String text="";
private Bitmap img = null;
public MyOverLay(GeoPoint gp1,GeoPoint gp2,int mode) // GeoPoint is a int. (6E)
{
this.gp1 = gp1;
this.gp2 = gp2;
this.mode = mode;
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 void setText(String t)
{
this.text = t;
}
public void setBitmap(Bitmap bitmap)
{
this.img = bitmap;
}
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¡Gstart
if(mode==1)
{
if(defaultColor==999)
paint.setColor(Color.BLUE);
else
paint.setColor(defaultColor);
RectF oval=new RectF(point.x - mRadius, point.y - mRadius,
point.x + mRadius, point.y + mRadius);
// start point
canvas.drawOval(oval, paint);
}
// mode=2¡Gpath
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¡Gend */
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);
RectF oval=new RectF(point2.x - mRadius,point2.y - mRadius,
point2.x + mRadius,point2.y + mRadius);
/* end point */
paint.setAlpha(255);
canvas.drawOval(oval, paint);
}
/* mode=4¡Gcar */
else if(mode==4)
{
if(defaultColor==999)
paint.setColor(Color.GREEN);
else
paint.setColor(defaultColor);
Point point2 = new Point();
projection.toPixels(gp2, point2);
paint.setTextSize(20);
paint.setAntiAlias(true);
canvas.drawBitmap(img, point2.x, point2.y,paint);
canvas.drawText(this.text, point2.x, point2.y, paint);
// Log.d(TAG, "Draw the text="+this.text+ " at point="+point2.x + "," + point2.y);
}
else if(mode==5)
{
if(defaultColor==999)
paint.setColor(Color.GREEN);
else
paint.setColor(defaultColor);
Point point2 = new Point();
projection.toPixels(gp2, point2);
paint.setTextSize(20);
paint.setAntiAlias(true);
canvas.drawBitmap(img, point2.x, point2.y,paint);
// Log.d(TAG, "Draw the text="+this.text+ " at point="+point2.x + "," + point2.y);
}
}
return super.draw(canvas, mapView, shadow, when);
}
}
step 2: Create a class name DrivingDirectionActivity.java
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.w3c.dom.Document;
import org.xml.sax.SAXException;
import android.graphics.Color;
import android.os.Bundle;
import android.util.Log;
import com.android.code.R;
import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapActivity;
import com.google.android.maps.MapView;
/**
* @author ashish
*
*
*
*/
public class DrivingDirectionActivity extends MapActivity {
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.google_map_driving_direction_view);
MapView mapView = (MapView) findViewById(R.id.myMapView1);
double src_lat = 28.632808;
double src_long = 77.218276;
double dest_lat = 28.588535;
double dest_long = 77.255130;
GeoPoint srcGeoPoint = new GeoPoint((int) (src_lat * 1E6),
(int) (src_long * 1E6));
GeoPoint destGeoPoint = new GeoPoint((int) (dest_lat * 1E6),
(int) (dest_long * 1E6));
DrawPath(srcGeoPoint, destGeoPoint, Color.GREEN, mapView);
mapView.getController().animateTo(srcGeoPoint);
mapView.getController().setZoom(15);
}
/* (non-Javadoc)
* @see com.google.android.maps.MapActivity#isRouteDisplayed()
*/
protected boolean isRouteDisplayed() {
// TODO Auto-generated method stub
return false;
}
private void DrawPath(GeoPoint src, GeoPoint dest, int color,MapView mMapView01) {
// connect to map web service
Document doc = getDocument(makeUrl(src,dest));
System.out.println(doc.toString());
try {
if (doc.getElementsByTagName("GeometryCollection").getLength() > 0) {
// String path =
// doc.getElementsByTagName("GeometryCollection").item(0).getFirstChild().getFirstChild().getNodeName();
String path = doc.getElementsByTagName("GeometryCollection")
.item(0).getFirstChild().getFirstChild()
.getFirstChild().getNodeValue();
Log.d("xxx", "path=" + path);
String[] pairs = path.split(" ");
String[] lngLat = pairs[0].split(","); // lngLat[0]=longitude
// lngLat[1]=latitude
// lngLat[2]=height
// src
GeoPoint startGP = new GeoPoint((int) (Double.parseDouble(lngLat[1]) * 1E6),
(int) (Double.parseDouble(lngLat[0]) * 1E6));
mMapView01.getOverlays().add(new MyOverLay(startGP, startGP, 1));
GeoPoint gp1;
GeoPoint gp2 = startGP;
for (int i = 1; i < pairs.length; i++) {
// the last one would be crash
lngLat = pairs[i].split(",");
gp1 = gp2;
// watch out! For GeoPoint, first:latitude, second:longitude
gp2 = new GeoPoint((int) (Double.parseDouble(lngLat[1]) * 1E6),
(int) (Double.parseDouble(lngLat[0]) * 1E6));
mMapView01.getOverlays().add(new MyOverLay(gp1, gp2, 2, color));
Log.d("xxx", "pair:" + pairs[i]);
}
mMapView01.getOverlays().add(new MyOverLay(dest, dest, 3)); // use
// the
// default
// color
}
} catch ( Exception e) {
e.printStackTrace();
}
}
private Document getDocument(String urlString) {
// TODO Auto-generated method stub
Document doc = null;
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 = db.parse(urlConnection.getInputStream());
} catch (Exception e) {
// TODO: handle exception
}
return doc;
}
private String makeUrl(GeoPoint src, GeoPoint dest) {
// TODO Auto-generated method stub
// get the kml (XML) doc. And parse it to get the coordinates(direction
// route).
StringBuilder urlString = new StringBuilder();
urlString.append("http://maps.google.com/maps?f=d&hl=en");
urlString.append("&saddr=");// from
urlString.append(Double.toString((double) src.getLatitudeE6() / 1.0E6));
urlString.append(",");
urlString.append(Double.toString((double) src.getLongitudeE6() / 1.0E6));
urlString.append("&daddr=");// to
urlString.append(Double.toString((double) dest.getLatitudeE6() / 1.0E6));
urlString.append(",");
urlString.append(Double.toString((double) dest.getLongitudeE6() / 1.0E6));
urlString.append("&ie=UTF8&0&om=0&output=kml");
Log.d("xxx", "URL=" + urlString.toString());
return urlString.toString();
}
}
now execute..
If this is not good then you can pass the your current location as source loaction
来源：https://stackoverflow.com/questions/6070968/google-maps-api-directions