Android Google Direction API未显示多个路径
我想显示从源到目标的多个路径,并且在我的URL中为方向API使用了参数Android Google Direction API未显示多个路径,android,google-maps,google-directions-api,Android,Google Maps,Google Directions Api,我想显示从源到目标的多个路径,并且在我的URL中为方向API使用了参数“alternatives=true”。但我无法显示多条路线。我想我的onPostExecute()方法的显示部分有问题。请解决我的问题 public void MapPoints(double SourceOne, double DestinationOne, double SourceTwo, double DestinationTwo){ //LatLng origin = points.get(
“alternatives=true”
。但我无法显示多条路线。我想我的onPostExecute()
方法的显示部分有问题。请解决我的问题
public void MapPoints(double SourceOne, double DestinationOne, double SourceTwo, double DestinationTwo){
//LatLng origin = points.get(0);
//LatLng dest = points.get(1);
double SourceOneDraw = SourceOne;
double DestinationOneDraw = DestinationOne;
double SourceTwoDraw = SourceTwo;
double DestinationTwoDraw = DestinationTwo;
LatLng origin = new LatLng(SourceOneDraw,DestinationOneDraw);
LatLng dest = new LatLng(SourceTwoDraw,DestinationTwoDraw);
// Getting URL to the Google Directions API
String url = getDirectionsUrl(origin, dest);
DownloadTask downloadTask = new DownloadTask();
// Start downloading json data from Google Directions API
downloadTask.execute(url);
}
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";
//Adding Alternative parameter
String alternative = "alternatives=true";
// Building the parameters to the web service
String parameters = str_origin+"&"+str_dest+"&"+sensor+"&"+alternative;
// 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());
Toast.makeText(getApplicationContext(),"Error",Toast.LENGTH_LONG).show();
}finally{
iStream.close();
urlConnection.disconnect();
}
return data;
}
// Fetches data from url passed
private class DownloadTask extends AsyncTask<String, Void, String> {
// Downloading data in non-ui thread
@Override
protected String doInBackground(String... url) {
// For storing data from web service
String data = "";
try{
// Fetching the data from web service
data = downloadUrl(url[0]);
}catch(Exception e){
Log.d("Background Task",e.toString());
}
return data;
}
// Executes in UI thread, after the execution of
// doInBackground()
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
ParserTask parserTask = new ParserTask();
// Invokes the thread for parsing the JSON data
parserTask.execute(result);
}
}
// A class to parse the Google Places in JSON format
private class ParserTask extends AsyncTask<String, Integer, List<List<HashMap<String,String>>> >{
// Parsing the data in non-ui thread
@Override
protected List<List<HashMap<String, String>>> doInBackground(String... jsonData) {
JSONObject jObject;
List<List<HashMap<String, String>>> routes = null;
try{
jObject = new JSONObject(jsonData[0]);
DirectionsJSONParser parser = new DirectionsJSONParser();
// Starts parsing data
routes = parser.parse(jObject);
}catch(Exception e){
e.printStackTrace();
}
return routes;
}
// Executes in UI thread, after the parsing process
@Override
protected void onPostExecute(List<List<HashMap<String, String>>> result) {
ArrayList<LatLng> points = null;
PolylineOptions lineOptions = null;
MarkerOptions markerOptions = new MarkerOptions();
// Traversing through all the routes
for(int i=0;i<result.size();i++){
points = new ArrayList<LatLng>();
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);
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.addAll(points);
lineOptions.width(5);
lineOptions.color(Color.RED);
}
// Drawing polyline in the Google Map for the i-th route
mMap.addPolyline(lineOptions);
}
}
public void映射点(双源一、双目的一、双源二、双目的二){
//车床原点=点。获取(0);
//LatLng dest=点。获取(1);
double SourceOneDraw=SourceOne;
double DestinationOneDraw=DestinationOne;
double SourceTwoDraw=SourceTwo;
双DestinationTwoDraw=DestinationTwo;
LatLng origin=新LatLng(SourceOneDraw,DestinationOneDraw);
LatLng dest=新的LatLng(源TwoDraw、目标TwoDraw);
//获取Google Directions API的URL
字符串url=getDirectionsUrl(源、目标);
DownloadTask DownloadTask=新的DownloadTask();
//开始从Google Directions API下载json数据
downloadTask.execute(url);
}
私有字符串getDirectionsUrl(LatLng来源,LatLng目的地){
//路线起点
字符串str_origin=“origin=“+origin.latitude+”,“+origin.longitude;
//路线目的地
字符串str_dest=“destination=”+dest.latitude+”,“+dest.longitude;
//传感器启用
字符串sensor=“sensor=false”;
//添加替代参数
String alternative=“alternatives=true”;
//为web服务构建参数
字符串参数=str_origin+“&”+str_dest+“&”+传感器+“&”+备选方案;
//输出格式
字符串输出=“json”;
//构建web服务的url
字符串url=”https://maps.googleapis.com/maps/api/directions/“+输出+”?“+参数;
返回url;
}
//从url下载json数据的方法
私有字符串下载URL(字符串strUrl)引发IOException{
字符串数据=”;
InputStream iStream=null;
HttpURLConnection-urlConnection=null;
试一试{
URL=新URL(strUrl);
//创建http连接以与url通信
urlConnection=(HttpURLConnection)url.openConnection();
//连接到url
urlConnection.connect();
//从url读取数据
iStream=urlConnection.getInputStream();
BufferedReader br=新的BufferedReader(新的InputStreamReader(iStream));
StringBuffer sb=新的StringBuffer();
字符串行=”;
而((line=br.readLine())!=null){
某人附加(行);
}
data=sb.toString();
br.close();
}捕获(例外e){
//Log.d(“下载url时出现异常”,例如toString());
Toast.makeText(getApplicationContext(),“Error”,Toast.LENGTH_LONG.show();
}最后{
iStream.close();
urlConnection.disconnect();
}
返回数据;
}
//从传递的url获取数据
私有类DownloadTask扩展了AsyncTask{
//在非ui线程中下载数据
@凌驾
受保护的字符串doInBackground(字符串…url){
//用于存储来自web服务的数据
字符串数据=”;
试一试{
//从web服务获取数据
数据=下载url(url[0]);
}捕获(例外e){
Log.d(“后台任务”,例如toString());
}
返回数据;
}
//在UI线程中执行,在
//doInBackground()
@凌驾
受保护的void onPostExecute(字符串结果){
super.onPostExecute(结果);
ParserTask ParserTask=新的ParserTask();
//调用线程以解析JSON数据
执行(结果);
}
}
//以JSON格式解析GooglePlaces的类
私有类ParserTask扩展了AsyncTask{
//解析非ui线程中的数据
@凌驾
受保护列表doInBackground(字符串…jsonData){
JSONObject jObject;
列表路由=空;
试一试{
jObject=新的JSONObject(jsonData[0]);
DirectionsJSONParser=新的DirectionsJSONParser();
//开始解析数据
routes=parser.parse(jObject);
}捕获(例外e){
e、 printStackTrace();
}
返回路线;
}
//解析过程后,在UI线程中执行
@凌驾
受保护的void onPostExecute(列表结果){
ArrayList points=null;
PolylineOptions lineOptions=null;
MarkerOptions MarkerOptions=新MarkerOptions();
//穿越所有路线
for(int i=0;i查看您的代码,我相信我看到了问题所在。您有一个for循环,在其中循环遍历结果:
for(int i=0;i<result.size();i++)
如果我错了,请纠正我,但上面的代码行似乎只执行一次,因为它不在循环中。这将导致在映射上只绘制一条路径。如果尝试将这行代码移动到for循环中,是否会在映射上获得多条路径?整个函数将如下所示:
@Override
protected void onPostExecute(List<List<HashMap<String, String>>> result) {
ArrayList<LatLng> points = null;
PolylineOptions lineOptions = null;
MarkerOptions markerOptions = new MarkerOptions();
// Traversing through all the routes
for(int i=0;i<result.size();i++){
points = new ArrayList<LatLng>();
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);
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.addAll(points);
lineOptions.width(5);
lineOptions.color(Color.RED);
// Drawing polyline in the Google Map for the i-th route
mMap.addPolyline(lineOptions);
}
}
@覆盖
受保护的void onPostExecute(列表结果){
ArrayList points=null;
PolylineOptions lineOptions=null;
MarkerOptions MarkerOptions=新MarkerOptions();
//穿越所有路线
对于(int i=0;我相信这非常有效:D现在我得到了显示的备选路线。
@Override
protected void onPostExecute(List<List<HashMap<String, String>>> result) {
ArrayList<LatLng> points = null;
PolylineOptions lineOptions = null;
MarkerOptions markerOptions = new MarkerOptions();
// Traversing through all the routes
for(int i=0;i<result.size();i++){
points = new ArrayList<LatLng>();
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);
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.addAll(points);
lineOptions.width(5);
lineOptions.color(Color.RED);
// Drawing polyline in the Google Map for the i-th route
mMap.addPolyline(lineOptions);
}
}