我正在使用谷歌地图来显示源和目的地之间的显示路线。我无法在它们之间显示多条路线。只显示一条路线。请帮助显示多条路线
我的代码如下：
1）路由解析器
/** 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<>() ;
JSONArray jRoutes;
JSONArray jLegs;
JSONArray jSteps;
JSONObject jDistance = null;
JSONObject jDuration = null;
try {
jRoutes = jObject.getJSONArray("routes");
/** Traversing l routes */
for(int i=0;i<jRoutes.length();i++){
jLegs = ( (JSONObject)jRoutes.get(i)).getJSONArray("legs");
List<HashMap<String, String>> path = new ArrayList<HashMap<String, String>>();
/** Traversing all legs */
for(int j=0;j<jLegs.length();j++){
/** Getting distance from the json data */
jDistance = ((JSONObject) jLegs.get(j)).getJSONObject("distance");
HashMap<String, String> hmDistance = new HashMap<String, String>();
hmDistance.put("distance", jDistance.getString("text"));
/** Getting duration from the json data */
jDuration = ((JSONObject) jLegs.get(j)).getJSONObject("duration");
HashMap<String, String> hmDuration = new HashMap<String, String>();
hmDuration.put("duration", jDuration.getString("text"));
/** Adding distance object to the path */
path.add(hmDistance);
/** Adding duration object to the path */
path.add(hmDuration);
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("points");
List<LatLng> list = decodePoly(polyline);
/** Traversing all points */
for(int l=0;l<list.size();l++){
HashMap<String, String> hm = new HashMap<>();
hm.put("lat", Double.toString((list.get(l)).latitude) );
hm.put("lng", Double.toString((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<>();
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;
}
2）路径创建代码
@Override
protected void onPostExecute(List<List<HashMap<String, String>>> result) {
ArrayList<LatLng> points;
PolylineOptions lineOptions = null;
String distance = "";
String duration = "";
// Traversing through all the routes
for (int i = 0; i < result.size(); i++) {
points = new ArrayList<>();
lineOptions = new PolylineOptions();
// Fetching i-th route
List<HashMap<String, String>> path = result.get(i);
// 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){ // Get distance from the list
distance = (String)point.get("distance");
continue;
}else if(j==1){ // Get duration from the list
duration = (String)point.get("duration");
continue;
}
double lat = Double.parseDouble(point.get("lat"));
double lng = Double.parseDouble(point.get("lng"));
LatLng position = new LatLng(lat, lng);
points.add(position);
}
// Adding all the points in the route to LineOptions
lineOptions.clickable(true);
lineOptions.addAll(points);
lineOptions.width(6);
lineOptions.color(Color.BLUE);
Log.d("onPostExecute","onPostExecute lineoptions decoded");
}
distanceR.setText(" ("+distance+")");
timeRequired.setText(duration);
// String s="Distance:"+distance + ", Duration:"+duration;
// Toast.makeText(getActivity(),s,Toast.LENGTH_SHORT).show();
// Drawing polyline in the Google Map for the i-th route
mMap.addPolyline(lineOptions);
}
}
注意：如果我在遍历路线中给出i的值，它会显示另一个但仍然一次只显示一条路线。我需要用不同的颜色显示所有可能的路线
答案 0 :(得分：0)
不是使points和lineOptions全局化，而是将它们作为方法的本地化
for (int i = 0; i < result.size(); i++) {
Points points = new ArrayList<>();
PolylineOptions lineOptions = new PolylineOptions();
..............
}
当你将它们设为全局时，每次创建一个新实例时，它都会覆盖前一个实例。
答案 1 :(得分：0)
谢谢，如果有人调查..
错误是，我只需要包含mMap.addPolyline（lineOptions）;内循环