我希望能够使用Google Maps API for Android在两个用户定义的地理点之间显示路线。我还想让用户选择要显示的路线类型,如步行、骑车、开车等。此外,我还想计算使用此路线需要的时间和距离。我已经尝试在网上搜索和查看其他stackoverflow问题,但都没有结果。我该怎么做?我应该如何编写代码?
//----编辑----//
我还想获取交通信息,如拥挤路线、拥堵等。
这是一些帮助你的代码。
String url=
"http://maps.googleapis.com/maps/api/directions/json?origin="
+ origin.latitude + "," + origin.longitude +"&destination="
+ destination.latitude + "," + destination.longitude + "&sensor=false";
要使用androidhttpclient获取数据,可以像这样操作:
HttpResponse response;
HttpGet request;
AndroidHttpClient client = AndroidHttpClient.newInstance("somename");
request = new HttpGet(url);
response = client.execute(request);
InputStream source = response.getEntity().getContent();
String returnValue = buildStringIOutils(source);
return returnValue;
buildStringIOUtils是什么:
private String buildStringIOutils(InputStream is) {
try {
return IOUtils.toString(is, "UTF-8");
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
JSONObject result = new JSONObject(returnValue);
JSONArray routes = result.getJSONArray("routes");
long distanceForSegment = routes.getJSONObject(0).getJSONArray("legs").getJSONObject(0).getJSONObject("distance").getInt("value");
JSONArray steps = routes.getJSONObject(0).getJSONArray("legs")
.getJSONObject(0).getJSONArray("steps");
List<LatLng> lines = new ArrayList<LatLng>();
for(int i=0; i < steps.length(); i++) {
String polyline = steps.getJSONObject(i).getJSONObject("polyline").getString("points");
for(LatLng p : decodePolyline(polyline)) {
lines.add(p);
}
}
其中 decodePolyline 方法如下:
/** POLYLINE DECODER - http://jeffreysambells.com/2010/05/27/decoding-polylines-from-google-maps-direction-api-with-java **/
private List<LatLng> decodePolyline(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;
}
Polyline polylineToAdd = mMap.addPolyline(new PolylineOptions().addAll(lines).width(3).color(Color.RED));
要更改模式,请将以下内容添加到URL中(参见https://developers.google.com/maps/documentation/directions/):&mode=YOUR_MODE
driving(默认)表示使用道路网络的标准驾驶方向。
walking请求通过行人路径和人行道(如有)获取步行路线。
bicycling请求通过自行车路径和首选街道(如有)获取自行车路线。
transit请求通过公共交通路线(如有)获取路线。
编辑: 关于“我也想获得交通信息,例如繁忙的路线、拥堵等。”我还没有研究过这个,但我的代码应该可以让您开始得很好。
编辑2: 在谷歌方向API中找到了这个: “对于驾驶路线:商业地图客户可以指定出发时间以考虑当前交通状况的行程持续时间。出发时间必须设置为距离当前时间几分钟之内。”
使用Wrapper库的Android Google Maps路由示例代码
使用Android Studio Gradle条目:
compile 'com.github.jd-alexander:library:1.1.0'
MainActivity.java
import android.Manifest;
import android.content.pm.PackageManager;
import android.graphics.Color;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v4.app.ActivityCompat;
import android.support.v4.app.FragmentActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;
import android.widget.Toast;
import com.directions.route.Route;
import com.directions.route.RouteException;
import com.directions.route.Routing;
import com.directions.route.RoutingListener;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
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.Polyline;
import com.google.android.gms.maps.model.PolylineOptions;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
public class MainActivity extends FragmentActivity implements OnMapReadyCallback, LocationListener, GoogleMap.OnMarkerClickListener, RoutingListener {
private GoogleMap mMap = null;
private LocationManager locationManager = null;
private FloatingActionButton fab = null;
private TextView txtDistance, txtTime;
//Global UI Map markers
private Marker currentMarker = null;
private Marker destMarker = null;
private LatLng currentLatLng = null;
private Polyline line = null;
//Global flags
private boolean firstRefresh = true;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_map);
Constants.POINT_DEST = new LatLng(18.758663, 73.382025); //Lonavala destination.
//Load the map fragment on UI
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
txtDistance = (TextView)findViewById(R.id.txt_distance);
txtTime = (TextView)findViewById(R.id.txt_time);
fab = (FloatingActionButton)findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
MainActivity.this.getRoutingPath();
Snackbar.make(v, "Fetching Route", Snackbar.LENGTH_SHORT).show();
}
});
}
@Override
protected void onResume() {
super.onResume();
firstRefresh = true;
//Ensure the GPS is ON and location permission enabled for the application.
locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
if (!PermissionCheck.getInstance().checkGPSPermission(this, locationManager)) {
//GPS not enabled for the application.
} else if (!PermissionCheck.getInstance().checkLocationPermission(this)) {
//Location permission not given.
} else {
Toast.makeText(MainActivity.this, "Fetching Location", Toast.LENGTH_SHORT).show();
try {
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 5000, 0, this);
} catch(Exception e)
{
Toast.makeText(MainActivity.this, "ERROR: Cannot start location listener", Toast.LENGTH_SHORT).show();
}
}
}
@Override
protected void onPause() {
if (locationManager != null) {
//Check needed in case of API level 23.
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
}
try {
locationManager.removeUpdates(this);
} catch (Exception e) {
}
}
locationManager = null;
super.onPause();
}
@Override
protected void onStop() {
super.onStop();
}
@Override
public void onMapReady(GoogleMap googleMap)
{
mMap = googleMap;
//mMap.getUiSettings().setZoomControlsEnabled(true);
mMap.getUiSettings().setCompassEnabled(true);
mMap.getUiSettings().setAllGesturesEnabled(true);
mMap.setOnMarkerClickListener(this);
}
/**
* @desc LocationListener Interface Methods implemented.
*/
@Override
public void onLocationChanged(Location location)
{
double lat = location.getLatitude();
double lng = location.getLongitude();
currentLatLng = new LatLng(lat, lng);
if(firstRefresh)
{
//Add Start Marker.
currentMarker = mMap.addMarker(new MarkerOptions().position(currentLatLng).title("Current Position"));//.icon(BitmapDescriptorFactory.fromResource(R.drawable.location)));
firstRefresh = false;
destMarker = mMap.addMarker(new MarkerOptions().position(Constants.POINT_DEST).title("Destination"));//.icon(BitmapDescriptorFactory.fromResource(R.drawable.location)));
mMap.moveCamera(CameraUpdateFactory.newLatLng(Constants.POINT_DEST));
mMap.animateCamera(CameraUpdateFactory.zoomTo(15));
getRoutingPath();
}
else
{
currentMarker.setPosition(currentLatLng);
}
}
@Override
public void onStatusChanged(String provider, int status, Bundle extras) {}
@Override
public void onProviderEnabled(String provider) {}
@Override
public void onProviderDisabled(String provider) {}
/**
* @desc MapMarker Interface Methods Implemented.
*/
@Override
public boolean onMarkerClick(Marker marker)
{
if(marker.getTitle().contains("Destination"))
{
//Do some task on dest pin click
}
else if(marker.getTitle().contains("Current"))
{
//Do some task on current pin click
}
return false;
}
/**
*@desc Routing Listener interface methods implemented.
**/
@Override
public void onRoutingFailure(RouteException e)
{
Toast.makeText(MainActivity.this, "Routing Failed", Toast.LENGTH_SHORT).show();
}
@Override
public void onRoutingStart() { }
@Override
public void onRoutingSuccess(ArrayList<Route> list, int i)
{
try
{
//Get all points and plot the polyLine route.
List<LatLng> listPoints = list.get(0).getPoints();
PolylineOptions options = new PolylineOptions().width(5).color(Color.BLUE).geodesic(true);
Iterator<LatLng> iterator = listPoints.iterator();
while(iterator.hasNext())
{
LatLng data = iterator.next();
options.add(data);
}
//If line not null then remove old polyline routing.
if(line != null)
{
line.remove();
}
line = mMap.addPolyline(options);
//Show distance and duration.
txtDistance.setText("Distance: " + list.get(0).getDistanceText());
txtTime.setText("Duration: " + list.get(0).getDurationText());
//Focus on map bounds
mMap.moveCamera(CameraUpdateFactory.newLatLng(list.get(0).getLatLgnBounds().getCenter()));
LatLngBounds.Builder builder = new LatLngBounds.Builder();
builder.include(currentLatLng);
builder.include(Constants.POINT_DEST);
LatLngBounds bounds = builder.build();
mMap.animateCamera(CameraUpdateFactory.newLatLngBounds(bounds, 50));
}
catch (Exception e)
{
Toast.makeText(MainActivity.this, "EXCEPTION: Cannot parse routing response", Toast.LENGTH_SHORT).show();
}
}
@Override
public void onRoutingCancelled()
{
Toast.makeText(MainActivity.this, "Routing Cancelled", Toast.LENGTH_SHORT).show();
}
/**
* @method getRoutingPath
* @desc Method to draw the google routed path.
*/
private void getRoutingPath()
{
try
{
//Do Routing
Routing routing = new Routing.Builder()
.travelMode(Routing.TravelMode.DRIVING)
.withListener(this)
.waypoints(currentLatLng, Constants.POINT_DEST)
.build();
routing.execute();
}
catch (Exception e)
{
Toast.makeText(MainActivity.this, "Unable to Route", Toast.LENGTH_SHORT).show();
}
}
}
Constants.java
/**
* @class Constants
* @desc Constant class for holding values at runtime.
*/
public class Constants
{
//Map LatLong points
public static LatLng POINT_DEST = null;
}
activity_map.xml
<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:map="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<LinearLayout
android:id="@+id/viewA"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="0.1"
android:orientation="horizontal">
<fragment
android:id="@+id/map"
android:name="com.google.android.gms.maps.SupportMapFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.packagename.MainActivity" />
</LinearLayout>
<LinearLayout
android:id="@+id/viewB"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="0.9"
android:gravity="center|left"
android:paddingLeft="20dp"
android:background="#FFFFFF"
android:orientation="vertical" >
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="16dp"
android:text="Distance ?"
android:paddingTop="3dp"
android:paddingLeft="3dp"
android:paddingBottom="3dp"
android:id="@+id/txt_distance" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="17dp"
android:paddingLeft="3dp"
android:text="Duration ?"
android:id="@+id/txt_time" />
</LinearLayout>
</LinearLayout>
<android.support.design.widget.FloatingActionButton
android:id="@+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="16dp"
android:clickable="true"
android:src="@android:drawable/ic_dialog_map"
app:layout_anchor="@id/viewA"
app:layout_anchorGravity="bottom|right|end"/>
</android.support.design.widget.CoordinatorLayout>
尝试使用Google Directions API。它是一个网络服务,提供JSON格式的逐步指南和所有信息,可通过汽车、公共交通或步行从A点到达B点。
要编写代码,请按照Stochastically评论中的链接进行操作。