java - 我们如何获取该Google Map v2中所有路线节点的音轨

在我的项目中，我需要制作一个导航应用程序以向盲人用户提供指导，因此我需要获取该Google地图中所有路线节点的音轨。我已经在网络上引用了许多导航教程，但是我没有得到所需的东西。对于任何帮助，我感谢您。

这是我的jsonparser类

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;

    try {
        jRoutes = jObject.getJSONArray("routes");

        /** Traversing all routes */
        for(int i=0;i<jRoutes.length();i++){
            jLegs = ( (JSONObject)jRoutes.get(i)).getJSONArray("legs");
            List path = new ArrayList<HashMap<String, String>>();

            /** Traversing all legs */
            for(int j=0;j<jLegs.length();j++){
                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("formatted_address");
                    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 : http://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;
}

}

最佳答案

没有用于指示方向的音轨，但是看起来您正在使用Google Directions API，如果您查看documentation，则会发现该路线的说明在JSON中以html_instructions的形式返回给您。

然后您将使用说明进行操作，并使用Text To Speech (TTS)引擎进行说明。

然而

如forbidden所述，将Directions API依次导航使用TOS

Google Maps/Google Earth APIs Terms of Service

Last updated: May 27, 2009
...
10. License Restrictions. Except as expressly permitted under the Terms, or unless you
have received prior written authorization from Google (or, as applicable, from the
provider of particular Content), Google's licenses above are subject to your adherence
to all of the restrictions below. Except as explicitly permitted in Section 7 or the
Maps APIs Documentation, you must not (nor may you permit anyone else to):
...
10.9 use the Service or Content with any products, systems, or applications for or in
connection with:

(a) real time navigation or route guidance, including but not limited to turn-by-turn
route guidance that is synchronized to the position of a user's sensor-enabled device;

and may be disabled for certain apps (somehow, at least on Android)... FromGeocode
scraping in .NET conversation:
This is not allowed by the API terms of use. You should not scrape Google Maps to
generate geocodes. We will block services that do automated queries of our servers.

Bret Taylor
Product Manager, Google Maps