通过在Google Map Android API V2中点击来计算用户位置与另一个位置之间的距离和时间

Question

我想通过在Google Map Android API V2中点击来计算用户位置与另一个位置之间的距离和时间。 现在，下面是在点击两个位置后获取并获取两点之间的距离和时间的代码。

使用此代码后，我将打开地图。

我无法标记两个位置，因此无法计算时间和距离

代码参考： -http : //wptrafficanalyzer.in/blog/driving-distance-and-travel-time-duration-between-two-locations-in-google-map-android-api-v2/

为什么我无法获得分数并无法计算时间和距离？

MainActivity.java

public class MainActivity extends FragmentActivity implements OnMapReadyCallback{

    GoogleMap map;
    ArrayList<LatLng> markerPoints;
    TextView tvDistanceDuration;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        tvDistanceDuration = (TextView) findViewById(R.id.tv_distance_time);

        // Initializing
        markerPoints = new ArrayList<LatLng>();

        // Getting reference to SupportMapFragment of the activity_main
        SupportMapFragment fm = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);

        // Getting Map for the SupportMapFragment
         fm.getMapAsync(this);


        // Enable MyLocation Button in the Map
        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;
        }
        map.setMyLocationEnabled(true);

        // Setting onclick event listener for the map
        map.setOnMapClickListener(new OnMapClickListener() {

            @Override
            public void onMapClick(LatLng point) {

                // Already two locations
                if(markerPoints.size()>1){
                    markerPoints.clear();
                    map.clear();
                }

                // Adding new item to the ArrayList
                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(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
                map.addMarker(options);

                // Checks, whether start and end locations are captured
                if(markerPoints.size() >= 2){
                    LatLng origin = markerPoints.get(0);
                    LatLng dest = 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 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";

        // Building the parameters to the web service
        String parameters = str_origin+"&"+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;
    }

    @Override
    public void onMapReady(GoogleMap googleMap) {
        GoogleMap map;
        map = googleMap;
        if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.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;
        }


        map.setMyLocationEnabled(true);
        map.getUiSettings().setMapToolbarEnabled(false);
        //  map.getUiSettings().setMyLocationButtonEnabled(false);
        //map.getUiSettings().setZoomControlsEnabled(false);
        //etc...
    }

    // 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 = 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]);
                DirectionsJSONParser parser = new DirectionsJSONParser();

                // 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(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 = (String)point.get("distance");
                        continue;
                    }else if(j==1){ // Get duration from the list
                        duration = (String)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(2);
                lineOptions.color(Color.RED);
            }

            tvDistanceDuration.setText("Distance:"+distance + ", Duration:"+duration);

            // Drawing polyline in the Google Map for the i-th route
            map.addPolyline(lineOptions);
        }
    }

   /* @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }*/
}

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >

    <TextView
        android:id="@+id/tv_distance_time"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world"
        android:layout_alignParentTop="true" />

    <fragment
        android:name="com.google.android.gms.maps.SupportMapFragment"
        xmlns:map="http://schemas.android.com/apk/res-auto"
        android:id="@+id/map"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/tv_distance_time" />

</RelativeLayout>

DirectionJsinParser.java

public class DirectionsJSONParser {

    /** Receives a JSONObject and returns a list of lists containing latitude and longitude */
    public List<List<HashMap<String,String>>> parse(JSONObject jObject){

        List<List<HashMap<String, String>>> routes = new ArrayList<List<HashMap<String,String>>>() ;
        JSONArray jRoutes = null;
        JSONArray jLegs = null;
        JSONArray jSteps = null;
        JSONObject jDistance = null;
        JSONObject jDuration = null;

        try {

            jRoutes = jObject.getJSONArray("routes");

            /** Traversing all routes */
            for(int i=0;i<jRoutes.length();i++){
                jLegs = ( (JSONObject)jRoutes.get(i)).getJSONArray("legs");

                List<HashMap<String, String>> path = new ArrayList<HashMap<String, String>>();

                /** Traversing all legs */
                for(int j=0;j<jLegs.length();j++){

                    /** Getting distance from the json data */
                    jDistance = ((JSONObject) jLegs.get(j)).getJSONObject("distance");
                    HashMap<String, String> hmDistance = new HashMap<String, String>();
                    hmDistance.put("distance", jDistance.getString("text"));

                    /** Getting duration from the json data */
                    jDuration = ((JSONObject) jLegs.get(j)).getJSONObject("duration");
                    HashMap<String, String> hmDuration = new HashMap<String, String>();
                    hmDuration.put("duration", jDuration.getString("text"));

                    /** Adding distance object to the path */
                    path.add(hmDistance);

                    /** Adding duration object to the path */
                    path.add(hmDuration);

                    jSteps = ( (JSONObject)jLegs.get(j)).getJSONArray("steps");

                    /** Traversing all steps */
                    for(int k=0;k<jSteps.length();k++){
                        String polyline = "";
                        polyline = (String)((JSONObject)((JSONObject)jSteps.get(k)).get("polyline")).get("points");
                        List<LatLng> list = decodePoly(polyline);

                        /** Traversing all points */
                        for(int l=0;l<list.size();l++){
                            HashMap<String, String> hm = new HashMap<String, String>();
                            hm.put("lat", Double.toString(((LatLng)list.get(l)).latitude) );
                            hm.put("lng", Double.toString(((LatLng)list.get(l)).longitude) );
                            path.add(hm);
                        }
                    }
                }
                routes.add(path);
            }
        } catch (JSONException e) {
            e.printStackTrace();
        }catch (Exception e){
        }
        return routes;
    }

    /**
     * Method to decode polyline points
     * Courtesy : jeffreysambells.com/2010/05/27/decoding-polylines-from-google-maps-direction-api-with-java
     * */
    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;
    }
}

从图中可以看到，我只得到这张地图。 无法标记和计算为教程，为什么？ 请帮我

Answer 1

要解决您的问题：

我无法标记两个位置，因此无法计算时间和距离
- 由于您更喜欢使用tap ，因此可以尝试使用onCameraMove() 。 如相机更改事件中所述
  
  在摄像机移动或用户与触摸屏交互时，会多次调用OnCameraMoveListener的onCameraMove()回调。
- 请检查问题4636中提供的解决方法-在gmaps-api-issues跟踪器中添加drag，dragStart，dragEnd处理程序。
计算用户位置与另一个位置之间的距离
- 您可以从“ 位置 ”中提供的公共方法列表中选择适合您的方法，以计算位置之间的距离和时间。
- 如上所述，
  - distanceBetween()计算两个位置之间的近似距离（以米为单位distanceBetween()计算两个位置之间最短路径的初始和最终方位。
  - distanceTo返回此位置和给定位置之间的近似距离（以米为单位）。
- 这篇SO帖子中的解决方案- 使用Google Map API V2查找地图上两个点之间的距离可能会有所帮助。
计算用户位置与另一个位置之间的时间
- 您可以使用Directions API中指定的traffic_model (defaults to best_guess)

最后，您还可以选择从Google Maps Android API实用程序库或Google Maps Directions API进行引用。

通过在Google Map Android API V2中点击来计算用户位置与另一个位置之间的距离和时间

问题描述

1 个解决方案

解决方案1
0 2016-08-23 08:32:14

通过在Google Map Android API V2中点击来计算用户位置与另一个位置之间的距离和时间

问题描述

1 个解决方案

解决方案1 0 2016-08-23 08:32:14

解决方案1
0 2016-08-23 08:32:14