在我的 android 应用程序中，我有一个 MapView，我要显示路线黑白两点，我实现了代码，但它只显示一半路线。我尝试了很多方法但无法解决它请帮助我在哪里做错了。这里是两个红点和蓝色路线的屏幕截图http://www.flickr.com/photos/77093196@N03/7117948377/
以下是代码：
MapdirectionsActivity.java
public class MapdirectionsActivity extends MapActivity {
/** Called when the activity is first created. */
MapView mapView;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mapView = (MapView) findViewById(R.id.mapview);
double src_lat = 17.3667; // the source
double src_long = 78.4667;
double dest_lat = 18.9647; // the destination
double dest_long = 72.8258;
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, mapView);
mapView.getController().animateTo(srcGeoPoint);
mapView.getController().setZoom(7);
}
@Override
protected boolean isRouteDisplayed() {
return false;
}
private void DrawPath(GeoPoint src, GeoPoint dest, MapView mMapView) {
// connect to map web service
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&om=1&output=kml");
Log.d("Map directions", "URL= " + urlString.toString());
// get the kml (XML) doc. And parse it to get the coordinates(direction route).
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());
if (doc.getElementsByTagName("GeometryCollection").getLength() > 0) {
String path = doc.getElementsByTagName("GeometryCollection").item(0).getFirstChild().getFirstChild().getFirstChild().getNodeValue();
Log.d("Map directions", "path= " + path);
String[] pairs = path.split(" ");
String[] lngLat = pairs[0].split(","); // lngLat[0]=longitude
// lngLat[1]=latitude
// lngLat[2]=height
GeoPoint startGP = new GeoPoint(
(int) (Double.parseDouble(lngLat[1]) * 1E6),
(int) (Double.parseDouble(lngLat[0]) * 1E6));
mMapView.getOverlays().add(new MyOverLay(startGP, startGP, 1));//starting point
GeoPoint gp1 = null;
GeoPoint gp2 = startGP;
for (int i = 1; i <pairs.length; i++)
{
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));
mMapView.getOverlays().add(new MyOverLay(gp1, gp2, 2));//route
}
mMapView.getOverlays().add(new MyOverLay(dest, dest, 3)); //last point
}
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (ParserConfigurationException e) {
e.printStackTrace();
} catch (SAXException e) {
e.printStackTrace();
}
}
}
MyOverLay.java
public class MyOverLay extends Overlay {
private GeoPoint gp1;
private GeoPoint gp2;
private int mRadius = 6;
private int mode = 0;
public MyOverLay(GeoPoint gp1, GeoPoint gp2, int mode) // Constructor
{
this.gp1 = gp1;
this.gp2 = gp2;
this.mode = mode;
}
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);
// start
if (mode == 1) {
paint.setColor(Color.RED);
RectF oval = new RectF(point.x - mRadius, point.y - mRadius,
point.x + mRadius, point.y + mRadius);
canvas.drawOval(oval, paint);// start point
}
// mode=2：path
else if (mode == 2) {
paint.setColor(Color.BLUE);
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=2：path
}
/* mode=3：end */
else if (mode == 3) {
/* the last path */
paint.setColor(Color.RED);
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);
paint.setAlpha(255);
canvas.drawOval(oval, paint);/* end point */
}
}
return super.draw(canvas, mapView, shadow, when);
}
}
主要的.xml
<?xml version="1.0" encoding="utf-8"?>
<com.google.android.maps.MapView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/mapview"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:apiKey="0E2QBBM0fi1TSN6J0hCLbETO8oscApDt5CDqgbQ"
android:clickable="true"
android:enabled="true" />