我想要的： 我的应用程序需要绘制从源到目的地的行车路线，这已经完成。我的问题是我需要一个从源到目的地的方向箭头。
我做了什么： 我能够绘制一个箭头，我也计算了角度，但不知道如何将该角度应用于代码，以便箭头旋转...我已经尝试了所有代码..没有任何作用，箭头在源头绘制但指向错误的方向。
PS：我试过这个Direction between two GeoPoints in Google map in android
没有找到解决方案
我不想显示谷歌地图服务..我的意思是我不想使用URI.parse()的东西。
以下是我正在使用的代码：
public class MapRouteActivity extends MapActivity {
LinearLayout linearLayout;
MapView mapView;
private Road mRoad;
public final double fromLat = 17.40531527709,
fromLon = 78.46830368042, toLat = 17.42091669870207,
toLon = 78.4507942199707;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mapView = (MapView) findViewById(R.id.mapview);
mapView.setBuiltInZoomControls(true);
new Thread() {
@Override
public void run() {
String url = RoadProvider
.getUrl(fromLat, fromLon, toLat, toLon);
InputStream is = getConnection(url);
mRoad = RoadProvider.getRoute(is);
mHandler.sendEmptyMessage(0);
}
}.start();
}
Handler mHandler = new Handler() {
public void handleMessage(android.os.Message msg) {
TextView textView = (TextView) findViewById(R.id.description);
textView.setText(mRoad.mName + " " + mRoad.mDescription);
MapOverlay mapOverlay = new MapOverlay(mRoad, mapView);
List<Overlay> listOfOverlays = mapView.getOverlays();
listOfOverlays.clear();
listOfOverlays.add(mapOverlay);
mapView.getController().setZoom(14);
mapView.invalidate();
};
};
private InputStream getConnection(String url) {
InputStream is = null;
try {
URLConnection conn = new URL(url).openConnection();
is = conn.getInputStream();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return is;
}
@Override
protected boolean isRouteDisplayed() {
return true;
}
class MapOverlay extends com.google.android.maps.Overlay {
Road mRoad;
ArrayList<GeoPoint> mPoints;
public MapOverlay(Road road, MapView mv) {
mRoad = road;
if (road.mRoute.length > 0) {
mPoints = new ArrayList<GeoPoint>();
for (int i = 0; i < road.mRoute.length; i++) {
mPoints.add(new GeoPoint(
(int) (road.mRoute[i][1] * 1000000),
(int) (road.mRoute[i][0] * 1000000)));
}
int moveToLat = (mPoints.get(0).getLatitudeE6() + (mPoints.get(
mPoints.size() - 1).getLatitudeE6() - mPoints.get(0)
.getLatitudeE6()) / 2);
int moveToLong = (mPoints.get(0).getLongitudeE6() + (mPoints
.get(mPoints.size() - 1).getLongitudeE6() - mPoints
.get(0).getLongitudeE6()) / 2);
GeoPoint moveTo = new GeoPoint(moveToLat, moveToLong);
MapController mapController = mv.getController();
mapController.animateTo(moveTo);
mapController.setZoom(7);
}
}
@Override
public boolean draw(Canvas canvas, MapView mv, boolean shadow, long when) {
super.draw(canvas, mv, shadow);
drawPath(mv, canvas);
return true;
}
public void drawPath(MapView mv, Canvas canvas) {
int x1 = -1, y1 = -1, x2 = -1, y2 = -1;
Paint paint = new Paint();
paint.setColor(Color.GREEN);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeWidth(3);
for (int i = 0; i < mPoints.size(); i++) {
Point point = new Point();
mv.getProjection().toPixels(mPoints.get(i), point);
x2 = point.x;
y2 = point.y;
if (i > 0) {
canvas.drawLine(x1, y1, x2, y2, paint);
}
x1 = x2;
y1 = y2;
}
Point pointFrom = new Point();
GeoPoint gp1 = new GeoPoint((int) (fromLat * 1E6),
(int) (fromLon * 1E6));
Point pointTo = new Point();
GeoPoint gp2 = new GeoPoint((int) (toLat * 1E6),
(int) (toLon * 1E6));
Projection projection = mapView.getProjection();
projection.toPixels(gp1, pointFrom);
projection.toPixels(gp2, pointTo);
Bitmap bmp = BitmapFactory.decodeResource(getResources(),R.drawable.arrow1);
double dlon = gp2.getLongitudeE6() - gp1.getLongitudeE6();
double dlat = gp2.getLatitudeE6() - gp1.getLatitudeE6();
double angle = getDegrees(fromLat, fromLon, toLat, toLon, 15);
Matrix matrix = new Matrix();
matrix.postTranslate(-25, -25);
matrix.postRotate((float)Math.toRadians(angle));
matrix.postTranslate(pointFrom.x, pointFrom.y);
paint.setAntiAlias(true);
paint.setFilterBitmap(true);
canvas.drawBitmap(bmp, matrix, paint);
}
}
double getDegrees(double lat1, double long1, double lat2, double long2, double headX) {
double dLat = Math.toRadians(lat2-lat1);
double dLon = Math.toRadians(long2-long1);
lat1 = Math.toRadians(lat1);
lat2 = Math.toRadians(lat2);
double y = Math.sin(dLon) * Math.cos(lat2);
double x = Math.cos(lat1)*Math.sin(lat2) -
Math.sin(lat1)*Math.cos(lat2)*Math.cos(dLon);
double brng = Math.toDegrees(Math.atan2(y, x));
// fix negative degrees
if(brng<0) {
brng=360-Math.abs(brng);
}
return brng - headX;
}
}
Road.java中的代码
public class Road {
public String mName;
public String mDescription;
public int mColor;
public int mWidth;
public double[][] mRoute = new double[][] {};
public Point[] mPoints = new Point[] {};
}
Point.java中的代码
包com.abhi.maproute;
public class Point {
String mName;
String mDescription;
String mIconUrl;
double mLatitude;
double mLongitude;
}
RoadProvider.java中的代码
package com.abhi.maproute;
/**
* @author asadafale
*
*/
import java.io.IOException;
import java.io.InputStream;
import java.util.Stack;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;
public class RoadProvider {
public static Road getRoute(InputStream is) {
KMLHandler handler = new KMLHandler();
try {
SAXParser parser = SAXParserFactory.newInstance().newSAXParser();
parser.parse(is, handler);
} catch (ParserConfigurationException e) {
e.printStackTrace();
} catch (SAXException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return handler.mRoad;
}
public static String getUrl(double fromLat, double fromLon, double toLat,
double toLon) {// connect to map web service
StringBuffer urlString = new StringBuffer();
urlString.append("http://maps.google.com/maps?f=d&hl=en");
urlString.append("&saddr=");// from
urlString.append(Double.toString(fromLat));
urlString.append(",");
urlString.append(Double.toString(fromLon));
urlString.append("&daddr=");// to
urlString.append(Double.toString(toLat));
urlString.append(",");
urlString.append(Double.toString(toLon));
urlString.append("&ie=UTF8&0&om=0&output=kml");
System.out.println("url..."+urlString.toString());
return urlString.toString();
}
}
class KMLHandler extends DefaultHandler {
Road mRoad;
boolean isPlacemark;
boolean isRoute;
boolean isItemIcon;
private Stack<String> mCurrentElement = new Stack<String>();
private String mString;
public KMLHandler() {
mRoad = new Road();
}
public void startElement(String uri, String localName, String name,
Attributes attributes) throws SAXException {
mCurrentElement.push(localName);
if (localName.equalsIgnoreCase("Placemark")) {
isPlacemark = true;
mRoad.mPoints = addPoint(mRoad.mPoints);
} else if (localName.equalsIgnoreCase("ItemIcon")) {
if (isPlacemark)
isItemIcon = true;
}
mString = new String();
}
public void characters(char[] ch, int start, int length)
throws SAXException {
String chars = new String(ch, start, length).trim();
mString = mString.concat(chars);
}
public void endElement(String uri, String localName, String name)
throws SAXException {
if (mString.length() > 0) {
if (localName.equalsIgnoreCase("name")) {
if (isPlacemark) {
isRoute = mString.equalsIgnoreCase("Route");
if (!isRoute) {
mRoad.mPoints[mRoad.mPoints.length - 1].mName = mString;
}
} else {
mRoad.mName = mString;
}
} else if (localName.equalsIgnoreCase("color") && !isPlacemark) {
mRoad.mColor = Integer.parseInt(mString, 16);
} else if (localName.equalsIgnoreCase("width") && !isPlacemark) {
mRoad.mWidth = Integer.parseInt(mString);
} else if (localName.equalsIgnoreCase("description")) {
if (isPlacemark) {
String description = cleanup(mString);
if (!isRoute)
mRoad.mPoints[mRoad.mPoints.length - 1].mDescription = description;
else
mRoad.mDescription = description;
}
} else if (localName.equalsIgnoreCase("href")) {
if (isItemIcon) {
mRoad.mPoints[mRoad.mPoints.length - 1].mIconUrl = mString;
}
} else if (localName.equalsIgnoreCase("coordinates")) {
if (isPlacemark) {
if (!isRoute) {
String[] xyParsed = split(mString, ",");
double lon = Double.parseDouble(xyParsed[0]);
double lat = Double.parseDouble(xyParsed[1]);
mRoad.mPoints[mRoad.mPoints.length - 1].mLatitude = lat;
mRoad.mPoints[mRoad.mPoints.length - 1].mLongitude = lon;
} else {
String[] coodrinatesParsed = split(mString, " ");
int lenNew = coodrinatesParsed.length;
int lenOld = mRoad.mRoute.length;
double[][] temp = new double[lenOld + lenNew][2];
for (int i = 0; i < lenOld; i++) {
temp[i] = mRoad.mRoute[i];
}
for (int i = 0; i < lenNew; i++) {
String[] xyParsed = split(coodrinatesParsed[i], ",");
for (int j = 0; j < 2 && j < xyParsed.length; j++)
temp[lenOld + i][j] = Double
.parseDouble(xyParsed[j]);
}
mRoad.mRoute = temp;
}
}
}
}
mCurrentElement.pop();
if (localName.equalsIgnoreCase("Placemark")) {
isPlacemark = false;
if (isRoute)
isRoute = false;
} else if (localName.equalsIgnoreCase("ItemIcon")) {
if (isItemIcon)
isItemIcon = false;
}
}
private String cleanup(String value) {
String remove = "<br/>";
int index = value.indexOf(remove);
if (index != -1)
value = value.substring(0, index);
remove = " ";
index = value.indexOf(remove);
int len = remove.length();
while (index != -1) {
value = value.substring(0, index).concat(
value.substring(index + len, value.length()));
index = value.indexOf(remove);
}
return value;
}
public Point[] addPoint(Point[] points) {
Point[] result = new Point[points.length + 1];
for (int i = 0; i < points.length; i++)
result[i] = points[i];
result[points.length] = new Point();
return result;
}
private static String[] split(String strString, String strDelimiter) {
String[] strArray;
int iOccurrences = 0;
int iIndexOfInnerString = 0;
int iIndexOfDelimiter = 0;
int iCounter = 0;
if (strString == null) {
throw new IllegalArgumentException("Input string cannot be null.");
}
if (strDelimiter.length() <= 0 || strDelimiter == null) {
throw new IllegalArgumentException(
"Delimeter cannot be null or empty.");
}
if (strString.startsWith(strDelimiter)) {
strString = strString.substring(strDelimiter.length());
}
if (!strString.endsWith(strDelimiter)) {
strString += strDelimiter;
}
while ((iIndexOfDelimiter = strString.indexOf(strDelimiter,
iIndexOfInnerString)) != -1) {
iOccurrences += 1;
iIndexOfInnerString = iIndexOfDelimiter + strDelimiter.length();
}
strArray = new String[iOccurrences];
iIndexOfInnerString = 0;
iIndexOfDelimiter = 0;
while ((iIndexOfDelimiter = strString.indexOf(strDelimiter,
iIndexOfInnerString)) != -1) {
strArray[iCounter] = strString.substring(iIndexOfInnerString,
iIndexOfDelimiter);
iIndexOfInnerString = iIndexOfDelimiter + strDelimiter.length();
iCounter += 1;
}
return strArray;
}
}