android谷歌地图寻找距离 [英] android google map finding distance

问题描述

我正在尝试找出两个位置之间的距离.我有经度和纬度，我可以计算欧几里得距离.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行驶的道路的距离.在这种情况下如何计算?

I am trying to find distance between two locations. I have longitudes and latitudes and I can calculate Euclidean distance. But I want to find road distance. I mean, , I want to calculate the distance of the road that I am going on while going to destination from source. In this case how to calculate this?

推荐答案

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

The easiest way would be to use the Google Directions API to get the directions, this gives you a list of all the points along the route (and the total distance).

查看:http://code.google.com/apis/maps/文档/说明/

如果您不确定如何执行此操作，请告诉我，我会为您发布一些代码，这些代码将从谷歌获取路线并提取您需要的数据.

If your not sure how to do this let me know and i'll post some code for you which will get the directions from google and extract the data you need.

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，只需返回 sDistance 或 iDistance.

This will return the distance between the two points, you can change the function to return it as a string or as an integer, just return either sDistance or iDistance.

希望这对您有所帮助，如果您需要更多帮助，请告诉我.

Hope this helps you, let me know if you need any more help.

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