我正在尝试显示Android中两个MarkerOptions点之间的行车路线。我找到了this tutorial here，这对我很有用，但我正在尝试调整它，以便MarkerOptions是我当前的位置和固定的LatLng对象，而不是你得到的两点你触摸地图。所以我的当前位置为LatLng = updatedLatLng，固定位置为LatLng = wcbcLatLng。在本教程中，onMapClick方法如下所示：
public void onTouchMap(){
// Setting onclick event listener for the map
this.mapG3.setOnMapClickListener(new OnMapClickListener() {
@Override
public void onMapClick(LatLng point) {
// Already two locations
if (Geo4.this.markerPoints.size() > 1) {
Geo4.this.markerPoints.clear();
Geo4.this.mapG3.clear();
}
// Adding new item to the ArrayList
Geo4.this.markerPoints.add(point);
// Creating MarkerOptions
MarkerOptions options = new MarkerOptions();
// Setting the position of the marker
options.position(point);
/**
* For the start location, the color of marker is GREEN and for
* the end location, the color of marker is RED.
*/
if (Geo4.this.markerPoints.size() == 1) {
options.icon(BitmapDescriptorFactory
.defaultMarker
(BitmapDescriptorFactory.HUE_GREEN));
} else if (Geo4.this.markerPoints.size() == 2) {
options.icon(BitmapDescriptorFactory
.defaultMarker
(BitmapDescriptorFactory.HUE_RED));
}
// Add new marker to the Google Map Android API V2
Geo4.this.mapG3.addMarker(options);
// Checks, whether start and end locations are captured
if (Geo4.this.markerPoints.size() >= 2) {
LatLng origin = Geo4.this.markerPoints.get(0);
LatLng dest = Geo4.this.markerPoints.get(1);
// Getting URL to the Google Directions API
String url = Geo4.this.getDirectionsUrl(origin, dest);
DownloadTask downloadTask = new DownloadTask();
// Start downloading json data from Google Directions API
downloadTask.execute(url);
}
}
});
}//-- END Method
这是我要修改的方法，以便查找我的updatedLatLng＆amp; wcbcLatLng代替LatLng origin＆amp;该方法当前正在使用的LatLng dest。任何帮助，将不胜感激！这是我的完整活动：
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import org.json.JSONObject;
import android.app.AlertDialog;
import android.content.Intent;
import android.graphics.Color;
import android.location.LocationManager;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import com.google.android.gms.common.GooglePlayServicesUtil;
import com.google.android.gms.maps.CameraUpdate;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.GoogleMap.OnMapClickListener;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.LatLngBounds;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.android.gms.maps.model.PolylineOptions;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.provider.Settings;
public class Geo4 extends FragmentActivity implements LocationListener {
GoogleMap mapG3;
ArrayList<LatLng> markerPoints;
TextView mapInfo_TV;
LocationManager locMan;
SupportMapFragment sMf;
Button back_btn, zoom_btn;
MarkerOptions startMO, wcbcMO, broncoMO;
MarkerOptions markers;
Marker currentMarker, wcbcMarker, broncoMarker;
LatLng updatedLatLng, directionsLatLng;
LatLng wcbcLatLng = new LatLng(30.393903, -97.682871);
LatLng oskiLatLng = new LatLng(30.474570, -97.973889);
LatLng point, point3t, point4t;
CameraUpdate cameraUpdate;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.geo3);
back_btn = (Button) findViewById(R.id.backMap_g3_btn);
zoom_btn = (Button) findViewById(R.id.marker_g3_btn);
this.mapInfo_TV = (TextView) this.findViewById(R.id.map_g3Info_TV);
// Initializing
this.markerPoints = new ArrayList<LatLng>();
// Getting reference to SupportMapFragment of the activity_main
sMf = (SupportMapFragment) this.getSupportFragmentManager()
.findFragmentById(R.id.map_g3_FRAG);
// Getting Map for the SupportMapFragment
this.mapG3 = sMf.getMap();
// --- fire Methods
googlePlay();
getCurrentLocation();
onTouchMap();
// --- END fire Methods
// --- Back button
back_btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
// mapG3.clear();
Intent backmapI = new Intent(
"com.my.package.BUTTON_INTERFACE");
startActivity(backmapI);
}
});
// --- end Back button
// --- Zoom button
zoom_btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
getDirections4T(point4t);
}
});
// --- end Zoom button
}// --- END onCreate
// --- Methods ----
public void googlePlay() {
// ---- Google Play
// Getting Google Play availability status
int status = GooglePlayServicesUtil
.isGooglePlayServicesAvailable(getBaseContext());
if (status != ConnectionResult.SUCCESS) { // Google Play Services are
// not available
int requestCode = 10;
Dialog dialog = GooglePlayServicesUtil.getErrorDialog(status, this,
requestCode);
dialog.show();
} else { // Google Play Services are available
//Toast.makeText(getApplicationContext(),"Services Launched Fo Sho'",Toast.LENGTH_SHORT).show();
}
}
// ---- END Method
public void getCurrentLocation(){
// Getting LocationManager object from System Service LOCATION_SERVICE
locMan = (LocationManager) getSystemService(LOCATION_SERVICE);
boolean enabledGPS = locMan
.isProviderEnabled(LocationManager.GPS_PROVIDER);
boolean enabledWiFi = locMan
.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
// Check if enabled and if not send user to the GPS settings
if (!enabledGPS && !enabledWiFi) {
Toast.makeText(getApplicationContext(), "GPS signal not found",
Toast.LENGTH_LONG).show();
Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
startActivity(intent);
}
// Creating a criteria object to retrieve provider
Criteria criteria = new Criteria();
// Getting the name of the best provider
String provider = locMan.getBestProvider(criteria, true);
// Getting Current Location From GPS
Location oLc = locMan.getLastKnownLocation(provider);
if (oLc != null) {
onLocationChanged(oLc);
}
locMan.requestLocationUpdates(provider, 20000, 0, this);
}//--- END Method
public void zoomToFit() {
// --- zoom to fit
LatLngBounds.Builder builder = new LatLngBounds.Builder();
builder.include(wcbcLatLng);
builder.include(updatedLatLng);
LatLngBounds bounds = builder.build();
int padding = 50; // offset from edges of the map in pixels
cameraUpdate = CameraUpdateFactory.newLatLngBounds(bounds, padding);
mapG3.animateCamera(cameraUpdate);
// --- END zoom to fit
}// --- END Method
public void addwcbcMarkerOption() {
wcbcMO = new MarkerOptions().position(wcbcLatLng).title(
"Destination");
wcbcMO.icon(BitmapDescriptorFactory
.defaultMarker(BitmapDescriptorFactory.HUE_VIOLET));
mapG3.addMarker(wcbcMO);
cameraUpdate = CameraUpdateFactory.newLatLngZoom(wcbcLatLng, 15);
mapG3.animateCamera(cameraUpdate);
}// --- END Method
public void getDirections4T(LatLng point4t) {
Geo4.this.markerPoints.add(point4t);
markers = new MarkerOptions();
markers.position(wcbcLatLng);
markers.position(oskiLatLng);
if (Geo4.this.markerPoints.size() == 1) {
markers.icon(BitmapDescriptorFactory
.defaultMarker(BitmapDescriptorFactory.HUE_GREEN));
} else if (Geo4.this.markerPoints.size() == 2) {
markers.icon(BitmapDescriptorFactory
.defaultMarker(BitmapDescriptorFactory.HUE_RED));
}
Geo4.this.mapG3.addMarker(markers);
}//--- END Method
public void onTouchMap(){
// Setting onclick event listener for the map
this.mapG3.setOnMapClickListener(new OnMapClickListener() {
@Override
public void onMapClick(LatLng point) {
// Already two locations
if (Geo4.this.markerPoints.size() > 1) {
Geo4.this.markerPoints.clear();
Geo4.this.mapG3.clear();
}
// Adding new item to the ArrayList
Geo4.this.markerPoints.add(point);
// Creating MarkerOptions
MarkerOptions options = new MarkerOptions();
// Setting the position of the marker
options.position(point);
/**
* For the start location, the color of marker is GREEN and for
* the end location, the color of marker is RED.
*/
if (Geo4.this.markerPoints.size() == 1) {
options.icon(BitmapDescriptorFactory
.defaultMarker
(BitmapDescriptorFactory.HUE_GREEN));
} else if (Geo4.this.markerPoints.size() == 2) {
options.icon(BitmapDescriptorFactory
.defaultMarker
(BitmapDescriptorFactory.HUE_RED));
}
// Add new marker to the Google Map Android API V2
Geo4.this.mapG3.addMarker(options);
// Checks, whether start and end locations are captured
if (Geo4.this.markerPoints.size() >= 2) {
LatLng origin = Geo4.this.markerPoints.get(0);
LatLng dest = Geo4.this.markerPoints.get(1);
// Getting URL to the Google Directions API
String url = Geo4.this.getDirectionsUrl(origin, dest);
DownloadTask downloadTask = new DownloadTask();
// Start downloading json data from Google Directions API
downloadTask.execute(url);
}
}
});
}//-- END Method
private String getDirectionsUrl(LatLng updatedLatLng, LatLng dest) {
// Origin of route
String str_updatedLatLng = "origin=" + updatedLatLng.latitude + ","
+ updatedLatLng.longitude;
// Destination of route
String str_dest = "destination=" + dest.latitude + "," + dest.longitude;
// Sensor enabled
String sensor = "sensor=false";
// Building the parameters to the web service
String parameters = str_updatedLatLng + "&" + str_dest + "&" + sensor;
// Output format
String output = "json";
// Building the url to the web service
String url = "https://maps.googleapis.com/maps/api/directions/"
+ output + "?" + parameters;
return url;
}
/** A method to download json data from url */
private String downloadUrl(String strUrl) throws IOException {
String data = "";
InputStream iStream = null;
HttpURLConnection urlConnection = null;
try {
URL url = new URL(strUrl);
// Creating an http connection to communicate with url
urlConnection = (HttpURLConnection) url.openConnection();
// Connecting to url
urlConnection.connect();
// Reading data from url
iStream = urlConnection.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(
iStream));
StringBuffer sb = new StringBuffer();
String line = "";
while ((line = br.readLine()) != null) {
sb.append(line);
}
data = sb.toString();
br.close();
} catch (Exception e) {
Log.d("Exception while downloading url", e.toString());
} finally {
iStream.close();
urlConnection.disconnect();
}
return data;
}
// Fetches data from url passed
private class DownloadTask extends AsyncTask<String, Void, String> {
// Downloading data in non-ui thread
@Override
protected String doInBackground(String... url) {
// For storing data from web service
String data = "";
try {
// Fetching the data from web service
data = Geo4.this.downloadUrl(url[0]);
} catch (Exception e) {
Log.d("Background Task", e.toString());
}
return data;
}
// Executes in UI thread, after the execution of
// doInBackground()
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
ParserTask parserTask = new ParserTask();
// Invokes the thread for parsing the JSON data
parserTask.execute(result);
}
}
/** A class to parse the Google Places in JSON format */
private class ParserTask extends
AsyncTask<String, Integer, List<List<HashMap<String, String>>>> {
// Parsing the data in non-ui thread
@Override
protected List<List<HashMap<String, String>>> doInBackground(
String... jsonData) {
JSONObject jObject;
List<List<HashMap<String, String>>> routes = null;
try {
jObject = new JSONObject(jsonData[0]);
Geo3JSON parser = new Geo3JSON();
// Starts parsing data
routes = parser.parse(jObject);
} catch (Exception e) {
e.printStackTrace();
}
return routes;
}
// Executes in UI thread, after the parsing process
@Override
protected void onPostExecute(List<List<HashMap<String, String>>> result) {
ArrayList<LatLng> points = null;
PolylineOptions lineOptions = null;
MarkerOptions markerOptions = new MarkerOptions();
String distance = "";
String duration = "";
if (result.size() < 1) {
Toast.makeText(Geo4.this.getBaseContext(), "No Points",
Toast.LENGTH_SHORT).show();
return;
}
// Traversing through all the routes
for (int i = 0; i < result.size(); i++) {
points = new ArrayList<LatLng>();
lineOptions = new PolylineOptions();
// Fetching i-th route
List<HashMap<String, String>> path = result.get(i);
// Fetching all the points in i-th route
for (int j = 0; j < path.size(); j++) {
HashMap<String, String> point = path.get(j);
if (j == 0) { // Get distance from the list
distance = point.get("distance");
continue;
} else if (j == 1) { // Get duration from the list
duration = point.get("duration");
continue;
}
double lat = Double.parseDouble(point.get("lat"));
double lng = Double.parseDouble(point.get("lng"));
LatLng position = new LatLng(lat, lng);
points.add(position);
}
// Adding all the points in the route to LineOptions
lineOptions.addAll(points);
lineOptions.width(4);
lineOptions.color(Color.RED);
}
Geo4.this.mapInfo_TV.setText("Distance: " + distance + "les");
// Drawing polyline in the Google Map for the route
Geo4.this.mapG3.addPolyline(lineOptions);
}
}
// --- END Methods
// --- onLocationListener
@Override
public void onLocationChanged(Location oLc) {
updatedLatLng = new LatLng(oLc.getLatitude(), oLc.getLongitude());
startMO = new MarkerOptions().position(updatedLatLng)
.title("You Are Here")
.icon(BitmapDescriptorFactory
.defaultMarker(BitmapDescriptorFactory.HUE_ORANGE));
mapG3.addMarker(startMO);
addwcbcMarkerOption();
locMan.removeUpdates(this);
}
@Override
public void onProviderDisabled(String provider) {
//
}
@Override
public void onProviderEnabled(String provider) {
//
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
//
}
// --- END onLocationListener
@Override
protected void onPause() {
super.onPause();
overridePendingTransition(R.anim.fadein, R.anim.fadeout);
finish();
}
// --- inflated menu
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.wcbcv, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.menu_legalnotices:
String LicenseInfo = GooglePlayServicesUtil
.getOpenSourceSoftwareLicenseInfo(getApplicationContext
());
AlertDialog.Builder LicenseDialog = new AlertDialog.Builder(
Geo4.this);
LicenseDialog.setTitle("Legal Notices");
LicenseDialog.setMessage(LicenseInfo);
LicenseDialog.show();
return true;
}
return super.onOptionsItemSelected(item);
}
// --- END inflated menu
}
答案 0 :(得分：3)
我明白了。我onTouchMap()的大部分内容都是获取onTouch信息并将这些整数转换为LatLng值。由于我已经有LatLng个值，因此我只需要方法的最后三行来获取LatLng并从中获取JSON数据。所以我重写了首先添加MarkerOptions和LatLng值的方法，然后我添加了旧方法的最后3行。所以这就是我的新方法的样子，它可以正常工作（通过调用其他3种方法）并绘制折线并以TextView显示英里距离。
public void addMarkers(){
wcbcMO = new MarkerOptions().position(wcbcLatLng)
.title("Destination")
.icon(BitmapDescriptorFactory
.defaultMarker(BitmapDescriptorFactory.HUE_VIOLET));
mapG3.addMarker(wcbcMO);
startMO = new MarkerOptions().position(updatedLatLng)
.title("You Are Here")
.icon(BitmapDescriptorFactory
.defaultMarker(BitmapDescriptorFactory.HUE_ORANGE));
mapG3.addMarker(startMO);
// Getting URL to the Google Directions API
String url = Geo4.this.getDirectionsUrl(updatedLatLng, wcbcLatLng);
DownloadTask downloadTask = new DownloadTask();
// Start downloading json data from Google Directions API
downloadTask.execute(url);
}//--- END Method
答案 1 :(得分：0)
public class MainActivity extends Activity {
static final LatLng HAMBURG = new LatLng(53.558, 9.927);
static final LatLng KIEL = new LatLng(53.551, 9.993);
private GoogleMap map;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
map = ((MapFragment) getFragmentManager().findFragmentById(R.id.map))
.getMap();
Marker hamburg = map.addMarker(new MarkerOptions().position(HAMBURG)
.title("Hamburg"));
Marker kiel = map.addMarker(new MarkerOptions()
.position(KIEL)
.title("Kiel")
.snippet("Kiel is cool")
.icon(BitmapDescriptorFactory
.fromResource(R.drawable.ic_launcher)));
map.moveCamera(CameraUpdateFactory.newLatLngZoom(HAMBURG, 15));
map.setMyLocationEnabled(true);
map.animateCamera(CameraUpdateFactory.zoomTo(10), 2000, null);
map.setOnMapClickListener(new OnMapClickListener() {
private double latitude;
private double longitude;
@Override
public void onMapClick(LatLng arg0) {
latitude = arg0.latitude;
longitude = arg0.longitude;
StringBuilder result = new StringBuilder();
try {
Geocoder geocoder = new Geocoder(MainActivity.this, Locale
.getDefault());
List<Address> addresses = geocoder.getFromLocation(
latitude, longitude, 1);
if (addresses.size() > 0) {
Address address = addresses.get(0);
result.append(address.getLocality()).append("\n");
result.append(address.getCountryName());
Toast.makeText(getApplicationContext(), result, 3000)
.show();
}
} catch (IOException e) {
Log.e("tag", e.getMessage());
}
}
});
}
public String makeURL (double sourcelat, double sourcelog, double destlat, double destlog ){
StringBuilder urlString = new StringBuilder();
urlString.append("http://maps.googleapis.com/maps/api/directions/json");
urlString.append("?origin=");// from
urlString.append(Double.toString(sourcelat));
urlString.append(",");
urlString
.append(Double.toString( sourcelog));
urlString.append("&destination=");// to
urlString
.append(Double.toString( destlat));
urlString.append(",");
urlString.append(Double.toString( destlog));
urlString.append("&sensor=false&mode=driving&alternatives=true");
return urlString.toString();
}
public class JSONParser {
InputStream is = null;
JSONObject jObj = null;
String json = "";
public JSONParser() {
}
public String getJSONFromUrl(String url) {
try {
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
json = sb.toString();
is.close();
} catch (Exception e) {
Log.e("Buffer Error", "Error converting result " + e.toString());
}
return json;
}
}
private String url;
JSONParser jParser = new JSONParser();
String json = jParser.getJSONFromUrl(url);
public void drawPath(String result) {
try {
final JSONObject json = new JSONObject(result);
JSONArray routeArray = json.getJSONArray("routes");
JSONObject routes = routeArray.getJSONObject(0);
JSONObject overviewPolylines = routes.getJSONObject("overview_polyline");
String encodedString = overviewPolylines.getString("points");
List<LatLng> list = decodePoly(encodedString);
for(int z = 0; z<list.size()-1;z++){
LatLng src= list.get(z);
LatLng dest= list.get(z+1);
Polyline line = map.addPolyline(new PolylineOptions()
.add(new LatLng(src.latitude, src.longitude), new LatLng(dest.latitude, dest.longitude))
.width(2)
.color(Color.BLUE).geodesic(true));
}
}
catch (JSONException e) {
}
}
private List<LatLng> decodePoly(String encoded) {
List<LatLng> poly = new ArrayList<LatLng>();
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;
LatLng p = new LatLng( (((double) lat / 1E5)),
(((double) lng / 1E5) ));
poly.add(p);
}
return poly;
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
} }