工作概述..
我正在处理一个项目，其中我们计算用户当前位置和附近用户位置之间的行驶距离。
这可能是一个重复的问题，用于单点距离计算，但我想在自定义列表视图中计算多个位置的距离。
其他附近用户位置来自Web API，具有其名称和详细信息。
为了获取两点之间的行驶距离，我使用谷歌方向API。
它会给我结果，但会拖慢应用程序，并且如果有更多数据，则会挂起设备。
要求 :
我需要在自定义列表视图中准确、流畅地找到两个位置之间的行驶距离。
我已经完成的事情 :
我找到了这个链接异步加载，但它也没有正常工作。 当滚动ListView时，应用程序会崩溃。
这里是异步加载的代码。
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
viewHolder holder;
if (convertView == null) {
holder = new viewHolder();
} else {
holder = (viewHolder) convertView.getTag();
}
new getDistanceAsyncTask(position, holder, userLatt, userLong, sLatt1, sLong1).executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, null);
return convertView;
}
private static class getDistanceAsyncTask extends AsyncTask {
private int mPosition;
private viewHolder mHolder;
double Lat1, Lng1, Lat2, Lng2;
public getDistanceAsyncTask(int position, viewHolder holder, double lat1, double lng1, double lat2, double lng2) {
mPosition = position;
mHolder = holder;
this.Lat1 = lat1;
this.Lng1 = lng1;
this.Lat2 = lat2;
this.Lng2 = lng2;
}
@Override
protected Object doInBackground(Object... params) {
// TODO Auto-generated method stub
String distanceST = "";
Double dist = 0.0;
String uri = "http://maps.googleapis.com/maps/api/directions/json?origin=" + Lat1 + "," + Lng1 + "&destination=" + Lat2 + "," + Lng2 + "&mode=driving&sensor=false";
String result = GET(uri);
Log.d("result", "res=" + result);
JSONObject jsonObject = new JSONObject();
try {
jsonObject = new JSONObject(result.toString());
JSONArray array = jsonObject.getJSONArray("routes");
JSONObject routes = array.getJSONObject(0);
JSONArray legs = routes.getJSONArray("legs");
JSONObject steps = legs.getJSONObject(0);
JSONObject distance = steps.getJSONObject("distance");
distanceST = distance.getString("text");
dist = Double.parseDouble(distanceST.replaceAll("[^\\.0123456789]", ""));
// Utils.showToastMsg( HomeActivity.this, "Dist is :: " + dist );
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return distanceST;
}
@Override
protected void onPostExecute(Object result) {
// TODO Auto-generated method stub
mHolder.txtMerDistance1.setText(result.toString());
}
}
private static String GET(String url) {
InputStream inputStream = null;
String result = "";
try {
// create HttpClient
HttpClient httpclient = new DefaultHttpClient();
// make GET request to the given URL
HttpResponse httpResponse = httpclient.execute(new HttpGet(url));
// receive response as inputStream
inputStream = httpResponse.getEntity().getContent();
// convert inputstream to string
if (inputStream != null)
result = convertInputStreamToString(inputStream);
else
result = "not work!";
} catch (Exception e) {
Log.d("InputStream", "hello" + e);
}
return result;
}
private static String convertInputStreamToString(InputStream inputStream) throws IOException {
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
String line = "";
String result = "";
while ((line = bufferedReader.readLine()) != null)
result += line;
inputStream.close();
return result;
}
如果有最好的解决方案，请帮忙。