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我試圖弄清楚如何顯示從當前位置到四個已知位置的行駛距離。我沒有在屏幕上顯示地圖，我只需要顯示用戶目前距離這些地點有多少英里。我以Here爲例做了一些修改。它正在帶回正確的距離，但我無法弄清楚如何通過每個4個終端位置，或者區分它們。谷歌地圖API v2 - 獲取從當前位置到已知位置的行車距離
我需要做些什麼才能獲得到4個位置的距離，並在不同的TextView中顯示每個距離？
更新問題：如何分別計算每個4個TextView的距離？
有了下面的代碼，我能夠做我想做的第一個TextView的
的Java
public class Locations extends Fragment {
private Location currentLocation = null;
private LocationManager locationManager;
private GeoPoint currentPoint;
TextView location1;
ArrayList<LatLng> markerPoints;
GoogleMap map;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getLastLocation();
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.activity_locations, container, false);
...some other stuff being done here...
// Return view
return view;
}
public void getLastLocation(){
String provider = getBestProvider();
currentLocation = locationManager.getLastKnownLocation(provider);
this.markerPoints = new ArrayList<LatLng>();
LatLng fromPosition = new LatLng(currentLocation.getLatitude(), currentLocation.getLongitude());
LatLng toPosition = new LatLng(29.633289, -82.305838);
// These are the other 3 end locations
LatLng toPosition1 = new LatLng(35.205374, -82.614587);
LatLng toPosition2 = new LatLng(35.405342, -82.316587);
LatLng toPosition3 = new LatLng(35.702354, -82.515837);
Locations.this.markerPoints.add(fromPosition);
Locations.this.markerPoints.add(toPosition);
// Getting URL to the Google Directions API
String url = Locations.this.getDirectionsUrl(fromPosition, toPosition);
DownloadTask downloadTask = new DownloadTask();
// Start downloading json data from Google Directions API
downloadTask.execute(url);
if(currentLocation != null) {
setCurrentLocation(currentLocation);
} else {
// do something
}
}
public String getBestProvider() {
locationManager = (LocationManager) getActivity().getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
criteria.setPowerRequirement(Criteria.NO_REQUIREMENT);
criteria.setAccuracy(Criteria.NO_REQUIREMENT);
String bestProvider = locationManager.getBestProvider(criteria, true);
return bestProvider;
}
public void setCurrentLocation(Location location){
// Get current location
int currLatitude = (int) (location.getLatitude()*1E6);
int currLongitude = (int) (location.getLongitude()*1E6);
currentPoint = new GeoPoint(currLatitude,currLongitude);
// Set current location
currentLocation = new Location("");
currentLocation.setLatitude(currentPoint.getLatitudeE6()/1e6);
currentLocation.setLongitude(currentPoint.getLongitudeE6()/1e6);
}
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;
}
// Fetches data from url passed
private class DownloadTask extends AsyncTask<String, Void, ArrayList<String>> {
@Override
protected ArrayList<String> doInBackground(String... urlList) {
try {
ArrayList<String> returnList = new ArrayList<String>();
for (String url : urlList) {
// Fetching the data from web service
String data = Locations.this.downloadUrl(url);
returnList.add(data);
}
return returnList;
} catch (Exception e) {
Log.d("Background Task", e.toString());
return null; // Failed, return null
}
}
// Executes in UI thread, after the execution of
// doInBackground()
@Override
protected void onPostExecute(ArrayList<String> results) {
super.onPostExecute(results);
ParserTask parserTask = new ParserTask();
for (String url : results) {
parserTask.execute(url);
}
// Invokes the thread for parsing the JSON data
// parserTask.execute(results);
}
}
/** A class to parse the Google Places in JSON format */
private class ParserTask extends AsyncTask<String, Integer, ArrayList<List<HashMap<String, String>>>> {
// Parsing the data in non-ui thread
@Override
protected ArrayList<List<HashMap<String, String>>> doInBackground(String... jsonData) {
try {
ArrayList<List<HashMap<String, String>>> routes = new ArrayList<List<HashMap<String, String>>>();
// for (String url : jsonData) {
for (int i = 0; i < jsonData.length; i++) {
JSONObject jObject = new JSONObject(jsonData[i]);
DirectionsJSONParser parser = new DirectionsJSONParser();
// Starts parsing data
routes = (ArrayList<List<HashMap<String, String>>>) parser.parse(jObject);
}
return routes;
} catch (Exception e) {
Log.d("Background task", e.toString());
return null; // Failed, return null
}
}
// Executes in UI thread, after the parsing process
@Override
protected void onPostExecute(ArrayList<List<HashMap<String, String>>> result) {
if (result.size() < 1) {
Toast.makeText(getActivity(), "No Points", Toast.LENGTH_LONG).show();
return;
}
TextView tv1 = (TextView) getActivity().findViewById(R.id.location1);
TextView tv2 = (TextView) getActivity().findViewById(R.id.location2);
TextView tv3 = (TextView) getActivity().findViewById(R.id.location3);
TextView tv4 = (TextView) getActivity().findViewById(R.id.location4);
TextView[] views = { tv1, tv2, tv3, tv4 };
// Traversing through all the routes
for (int i = 0; i < result.size(); i++) {
// Fetching i-th route
List<HashMap<String, String>> path = result.get(i);
String distance = "No distance";
// 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) {
distance = point.get("distance");
continue;
}
}
Log.d("Distance: ", distance);
// Set text
views[i].setText(distance);
}
}
}
XML
<?xml version="1.0" encoding="utf-8"?>
<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" >
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical" >
<TextView
android:id="@+id/location1"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<TextView
android:id="@+id/location2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="5dp"
android:text="TextView" />
<TextView
android:id="@+id/location3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="5dp"
android:text="TextView" />
<TextView
android:id="@+id/location4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="5dp"
android:text="TextView" />
</LinearLayout>
</RelativeLayout>
任何搞清楚了這幫助出來和/或建議，以更好的代碼將非常感激d。
您是否嘗試過單獨計算所有4條路徑，或者使用不同於'R.id.location1'的'TextView'？ – crocboy
我已經嘗試過每個人，例如，傳遞「toPosition1」並設置TextView在同一地點（非常最後一行在java文件中）和R.id.location2，它返回正確的距離，但我一次只能得到一個是正確的。如果我同時通過它們，它將爲每個4個TextView設置「距離」。 （希望是有道理的......） – Brian
所以你需要做的是創建一個'TextView'數組，並在最後你得到你通過該數組循環的距離，所以每個距離設置爲不同的'TextView' – crocboy