在这里，我发布了用于在当前位置和谷歌地图上的另一个地方之间绘制路线的完整代码。
更多详情：Visit draw route on google map with current location
PointParser 类
import android.content.Context;
import android.graphics.Color;
import android.os.AsyncTask;
import android.util.Log;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.PolylineOptions;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
public class PointsParser extends AsyncTask<String, Integer, List<List<HashMap<String, String>>>> {
TaskLoadedCallback taskCallback;
String directionMode = "driving";
public PointsParser(Context mContext, String directionMode) {
this.taskCallback = (TaskLoadedCallback) mContext;
this.directionMode = directionMode;
}
// 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]);
Log.d("mylog", jsonData[0].toString());
DataParser parser = new DataParser();
Log.d("mylog", parser.toString());
// Starts parsing data
routes = parser.parse(jObject);
Log.d("mylog", "Executing routes");
Log.d("mylog", routes.toString());
} catch (Exception e) {
Log.d("mylog", e.toString());
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;
PolylineOptions lineOptions = null;
// Traversing through all the routes
for (int i = 0; i < result.size(); i++) {
points = new ArrayList<>();
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);
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);
if (directionMode.equalsIgnoreCase("walking")) {
lineOptions.width(10);
lineOptions.color(Color.MAGENTA);
} else {
lineOptions.width(20);
lineOptions.color(Color.RED);
}
Log.d("mylog", "onPostExecute lineoptions decoded");
}
// Drawing polyline in the Google Map for the i-th route
if (lineOptions != null) {
//mMap.addPolyline(lineOptions);
taskCallback.onTaskDone(lineOptions);
} else {
Log.d("mylog", "without Polylines drawn");
}
}
}
FetchURL 类
import android.content.Context;
import android.os.AsyncTask;
import android.util.Log;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
public class FetchURL extends AsyncTask<String, Void, String> {
Context mContext;
String directionMode = "driving";
public FetchURL(Context mContext) {
this.mContext = mContext;
}
@Override
protected String doInBackground(String... strings) {
// For storing data from web service
String data = "";
directionMode = strings[1];
try {
// Fetching the data from web service
data = downloadUrl(strings[0]);
Log.d("mylog", "Background task data " + data.toString());
} catch (Exception e) {
Log.d("Background Task", e.toString());
}
return data;
}
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
PointsParser parserTask = new PointsParser(mContext, directionMode);
// Invokes the thread for parsing the JSON data
parserTask.execute(s);
}
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();
Log.d("mylog", "Downloaded URL: " + data.toString());
br.close();
} catch (Exception e) {
Log.d("mylog", "Exception downloading URL: " + e.toString());
} finally {
iStream.close();
urlConnection.disconnect();
}
return data;
}
}
主要活动
public class MainActivity extends AppCompatActivity implements GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener, com.google.android.gms.location.LocationListener , OnMapReadyCallback, TaskLoadedCallback{
//variables for map and route
private GoogleMap mMap;
private MarkerOptions place1, place2;
Button getDirection;
private Polyline currentPolyline;
private MapFragment mapFragment;
private boolean isFirstTime = true;
//variables for current location
private static final String TAG = "MainActivity";
private TextView tvLocation;
private GoogleApiClient mGoogleApiClient;
private Location mLocation;
private LocationRequest mLocationRequest;
private com.google.android.gms.location.LocationListener listener;
private long UPDATE_INTERVAL = 2 * 1000; /* 10 secs */
private long FASTEST_INTERVAL = 2000; /* 2 sec */
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//code for getting current location
requestMultiplePermissions();
tvLocation = (TextView) findViewById((R.id.tv));
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
}
//code for drawing route
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
mMap.clear();
Log.d("mylog", "Added Markers");
mMap.addMarker(place1);
mMap.addMarker(place2);
CameraPosition googlePlex = CameraPosition.builder()
.target(new LatLng(22.7739,71.6673))
.zoom(7)
.bearing(0)
.tilt(45)
.build();
mMap.animateCamera(CameraUpdateFactory.newCameraPosition(googlePlex), 5000, null);
}
private String getUrl(LatLng origin, LatLng dest, String directionMode) {
// Origin of route
String str_origin = "origin=" + origin.latitude + "," + origin.longitude;
// Destination of route
String str_dest = "destination=" + dest.latitude + "," + dest.longitude;
// Mode
String mode = "mode=" + directionMode;
// Building the parameters to the web service
String parameters = str_origin + "&" + str_dest + "&" + mode;
// Output format
String output = "json";
// Building the url to the web service
String url = "https://maps.googleapis.com/maps/api/directions/" + output + "?" + parameters + "&key=" + getString(R.string.google_maps_key);
return url;
}
@Override
public void onTaskDone(Object... values) {
if (currentPolyline != null)
currentPolyline.remove();
currentPolyline = mMap.addPolyline((PolylineOptions) values[0]);
}
//runtime permission method
private void requestMultiplePermissions(){
Dexter.withActivity(this)
.withPermissions(
Manifest.permission.ACCESS_FINE_LOCATION,
Manifest.permission.ACCESS_COARSE_LOCATION )
.withListener(new MultiplePermissionsListener() {
@Override
public void onPermissionsChecked(MultiplePermissionsReport report) {
// check if all permissions are granted
if (report.areAllPermissionsGranted()) {
Toast.makeText(getApplicationContext(), "All permissions are granted by user!", Toast.LENGTH_SHORT).show();
}
// check for permanent denial of any permission
if (report.isAnyPermissionPermanentlyDenied()) {
// show alert dialog navigating to Settings
openSettingsDialog();
}
}
@Override
public void onPermissionRationaleShouldBeShown(List<PermissionRequest> permissions, PermissionToken token) {
token.continuePermissionRequest();
}
}).
withErrorListener(new PermissionRequestErrorListener() {
@Override
public void onError(DexterError error) {
Toast.makeText(getApplicationContext(), "Some Error! ", Toast.LENGTH_SHORT).show();
}
})
.onSameThread()
.check();
}
private void openSettingsDialog() {
AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
builder.setTitle("Required Permissions");
builder.setMessage("This app require permission to use awesome feature. Grant them in app settings.");
builder.setPositiveButton("Take Me To SETTINGS", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
Uri uri = Uri.fromParts("package", getPackageName(), null);
intent.setData(uri);
startActivityForResult(intent, 101);
}
});
builder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
builder.show();
}
//methods for getting current location
@Override
public void onConnected(Bundle bundle) {
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// ActivityCompat#requestPermissions
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for ActivityCompat#requestPermissions for more details.
return;
}
startLocationUpdates();
mLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
if(mLocation == null){
startLocationUpdates();
}
if (mLocation != null) {
// mLatitudeTextView.setText(String.valueOf(mLocation.getLatitude()));
//mLongitudeTextView.setText(String.valueOf(mLocation.getLongitude()));
} else {
Toast.makeText(this, "Location not Detected", Toast.LENGTH_SHORT).show();
}
}
@Override
public void onConnectionSuspended(int i) {
Log.i(TAG, "Connection Suspended");
mGoogleApiClient.connect();
}
@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
Log.i(TAG, "Connection failed. Error: " + connectionResult.getErrorCode());
}
@Override
protected void onStart() {
super.onStart();
if (mGoogleApiClient != null) {
mGoogleApiClient.connect();
}
}
@Override
protected void onStop() {
super.onStop();
if (mGoogleApiClient.isConnected()) {
mGoogleApiClient.disconnect();
}
}
protected void startLocationUpdates() {
// Create the location request
mLocationRequest = LocationRequest.create()
.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY)
.setInterval(UPDATE_INTERVAL)
.setFastestInterval(FASTEST_INTERVAL);
// Request location updates
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
// TODO: Consider calling
// ActivityCompat#requestPermissions
// here to request the missing permissions, and then overriding
// public void onRequestPermissionsResult(int requestCode, String[] permissions,
// int[] grantResults)
// to handle the case where the user grants the permission. See the documentation
// for ActivityCompat#requestPermissions for more details.
return;
}
LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient,
mLocationRequest, this);
Log.d("reque", "--->>>>");
}
@Override
public void onLocationChanged(Location location) {
String msg = "Updated Location: " +
Double.toString(location.getLatitude()) + "," +
Double.toString(location.getLongitude());
tvLocation.setText(String.valueOf(location.getLatitude() +" "+String.valueOf(location.getLongitude())));
Toast.makeText(this, msg, Toast.LENGTH_SHORT).show();
if(isFirstTime){
//code to draw path on map
getDirection = findViewById(R.id.btnGetDirection);
getDirection.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
new FetchURL(MainActivity.this).execute(getUrl(place1.getPosition(), place2.getPosition(), "driving"), "driving");
}
});
place1 = new MarkerOptions().position(new LatLng(location.getLatitude(), location.getLongitude())).title("Location 1");
place2 = new MarkerOptions().position(new LatLng(20.8880, 70.4012)).title("Location 2");
mapFragment = (MapFragment) getFragmentManager().findFragmentById(R.id.mapNearBy);
mapFragment.getMapAsync(this);
isFirstTime = false;
}
}
}
如果您有任何错误，请查看此答案开头给出的原始教程。