我想借助经度和纬度在Google地图上显示路线方向。我已经尝试了一些代码，但是它给了我有关API方向的错误消息
该API项目无权使用此API。
我无法通过免费试用启用Direction API
我的代码段
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
int permission = ContextCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_FINE_LOCATION);
if (permission == PackageManager.PERMISSION_GRANTED) {
//mMap.setMyLocationEnabled(true);
// Add a marker in Sydney and move the camera
//LatLng sydney = new LatLng(lat, lon);
LatLng sydney = new LatLng(lat, lon);
mMap.addMarker(new MarkerOptions().position(sydney).title("Current Location"));
mMap.moveCamera(CameraUpdateFactory.newLatLng(sydney));
// mMap.setMyLocationEnabled(true);
} else {
requestPermission(
Manifest.permission.ACCESS_FINE_LOCATION,
LOCATION_REQUEST_CODE);
}
mMap.setOnMapClickListener(new GoogleMap.OnMapClickListener() {
@Override
public void onMapClick(LatLng latLng) {
if (markerPoints.size() > 1) {
markerPoints.clear();
mMap.clear();
}
// Adding new item to the ArrayList
markerPoints.add(latLng);
// Creating MarkerOptions
MarkerOptions options = new MarkerOptions();
// Setting the position of the marker
options.position(latLng);
if (markerPoints.size() == 1) {
options.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_GREEN));
} else if (markerPoints.size() == 2) {
options.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED));
}
// Add new marker to the Google Map Android API V2
mMap.addMarker(options);
// Checks, whether start and end locations are captured
if (markerPoints.size() >= 2) {
LatLng origin = (LatLng) markerPoints.get(0);
LatLng dest = (LatLng) markerPoints.get(1);
// Getting URL to the Google Directions API
String url = getDirectionsUrl(origin, dest);
DownloadTask downloadTask = new DownloadTask();
// Start downloading json data from Google Directions API
downloadTask.execute(url);
}
}
});
}
private class DownloadTask extends AsyncTask<String, Void, String> {
@Override
protected String doInBackground(String... url) {
String data = "";
try {
data = downloadUrl(url[0]);
} catch (Exception e) {
Log.d("Background Task", e.toString());
}
return data;
}
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
ParserTask parserTask = new ParserTask();
parserTask.execute(result);
}
}
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]);
DirectionsJSONParser parser = new DirectionsJSONParser();
routes = parser.parse(jObject);
} catch (Exception e) {
e.printStackTrace();
}
return routes;
}
@Override
protected void onPostExecute(List<List<HashMap<String, String>>> result) {
ArrayList<LatLng> points = new ArrayList<LatLng>();;
PolylineOptions lineOptions = new PolylineOptions();;
lineOptions.width(2);
lineOptions.color(Color.RED);
MarkerOptions markerOptions = new MarkerOptions();
// Traversing through all the routes
for(int i=0;i<result.size();i++){
// 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);
}
// Drawing polyline in the Google Map for the i-th route
if(points.size()!=0)mMap.addPolyline(lineOptions);//to avoid crash
}
}
private String getDirectionsUrl(LatLng origin, LatLng dest) {
// Origin of route
String str_origin = "origin=" + origin.latitude + "," + origin.longitude;
// Destination of route
String str_dest = "destination=" + dest.latitude + "," + dest.longitude;
// Sensor enabled
String sensor = "sensor=false";
String mode = "mode=driving";
String key = "key=" + getResources().getString(R.string.google_maps_key);
// Building the parameters to the web service
String parameters = str_origin + "&" + str_dest + "&" + key + "&" + mode;
// 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;
}
private String downloadUrl(String strUrl) throws IOException {
String data = "";
InputStream iStream = null;
HttpURLConnection urlConnection = null;
try {
URL url = new URL(strUrl);
urlConnection = (HttpURLConnection) url.openConnection();
urlConnection.connect();
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", e.toString());
} finally {
iStream.close();
urlConnection.disconnect();
}
return data;
}
答案 0 :(得分：0)