android谷歌地图寻找距离

Question

我想找到两个地点之间的距离.我有经度和纬度,我可以计算欧氏距离.但我想找到道路距离.我的意思是,我想计算从源头到目的地时我正在进行的道路距离.在这种情况下如何计算？

Answer 1

最简单的方法是使用Google Directions API获取路线,这会为您提供路线上所有点(以及总距离)的列表.

请访问:http://code.google.com/apis/maps/documentation/directions/

如果你不确定如何做到这一点让我知道,我会为你发布一些代码,它将从谷歌获取方向并提取你需要的数据.

更新 - 要求的代码

private void GetDistance(GeoPoint src, GeoPoint dest) {

    StringBuilder urlString = new StringBuilder();
    urlString.append("http://maps.googleapis.com/maps/api/directions/json?");
    urlString.append("origin=");//from
    urlString.append( Double.toString((double)src.getLatitudeE6() / 1E6));
    urlString.append(",");
    urlString.append( Double.toString((double)src.getLongitudeE6() / 1E6));
    urlString.append("&destination=");//to
    urlString.append( Double.toString((double)dest.getLatitudeE6() / 1E6));
    urlString.append(",");
    urlString.append( Double.toString((double)dest.getLongitudeE6() / 1E6));
    urlString.append("&mode=walking&sensor=true");
    Log.d("xxx","URL="+urlString.toString());

    // get the JSON And parse it to get the directions data.
    HttpURLConnection urlConnection= null;
    URL url = null;

    url = new URL(urlString.toString());
    urlConnection=(HttpURLConnection)url.openConnection();
    urlConnection.setRequestMethod("GET");
    urlConnection.setDoOutput(true);
    urlConnection.setDoInput(true);
    urlConnection.connect();

    InputStream inStream = urlConnection.getInputStream();
    BufferedReader bReader = new BufferedReader(new InputStreamReader(inStream));

    String temp, response = "";
    while((temp = bReader.readLine()) != null){
        //Parse data
        response += temp;
    }
    //Close the reader, stream & connection
    bReader.close();
    inStream.close();
    urlConnection.disconnect();

    //Sortout JSONresponse 
    JSONObject object = (JSONObject) new JSONTokener(response).nextValue();
    JSONArray array = object.getJSONArray("routes");
        //Log.d("JSON","array: "+array.toString());

    //Routes is a combination of objects and arrays
    JSONObject routes = array.getJSONObject(0);
        //Log.d("JSON","routes: "+routes.toString());

    String summary = routes.getString("summary");
        //Log.d("JSON","summary: "+summary);

    JSONArray legs = routes.getJSONArray("legs");
        //Log.d("JSON","legs: "+legs.toString());

    JSONObject steps = legs.getJSONObject(0);
            //Log.d("JSON","steps: "+steps.toString());

    JSONObject distance = steps.getJSONObject("distance");
        //Log.d("JSON","distance: "+distance.toString());

            String sDistance = distance.getString("text");
            int iDistance = distance.getInt("value");

}

这将返回两点之间的距离,您可以更改函数以将其作为字符串或整数返回,只返回sDistance或iDistance.

希望这对您有所帮助,请告诉我您是否需要更多帮助.

Answer 2

使用Google地图距离矩阵API http://code.google.com/apis/maps/documentation/distancematrix/.