Android - 在谷歌地图上显示方向

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如何获取并显示谷歌地图上的方向，如下图所示？ Screenshot Android - 在谷歌地图上显示方向

2015-10-21 Tam Le

试试这段代码，你需要google api pass key访问开发者的那个密钥试试这个代码这个工程。

import java.util.ArrayList; 
import java.util.HashMap; 
import java.util.List; 

import org.json.JSONObject; 

import android.graphics.Color; 
import android.os.AsyncTask; 
import android.os.Bundle; 
import android.support.v4.app.FragmentActivity; 
import android.util.Log; 

import com.google.android.gms.maps.CameraUpdateFactory; 
import com.google.android.gms.maps.GoogleMap; 
import com.google.android.gms.maps.SupportMapFragment; 
import com.google.android.gms.maps.model.LatLng; 
import com.google.android.gms.maps.model.MarkerOptions; 
import com.google.android.gms.maps.model.PolylineOptions; 

public class PathGoogleMapActivity extends FragmentActivity { 

    private static final LatLng LOWER_MANHATTAN = new LatLng(40.722543, 
      -73.998585); 
    private static final LatLng BROOKLYN_BRIDGE = new LatLng(40.7057, -73.9964); 
    private static final LatLng WALL_STREET = new LatLng(40.7064, -74.0094); 

    GoogleMap googleMap; 
    final String TAG = "PathGoogleMapActivity"; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_path_google_map); 
     SupportMapFragment fm = (SupportMapFragment) getSupportFragmentManager() 
       .findFragmentById(R.id.map); 
     googleMap = fm.getMap(); 

     MarkerOptions options = new MarkerOptions(); 
     options.position(LOWER_MANHATTAN); 
     options.position(BROOKLYN_BRIDGE); 
     options.position(WALL_STREET); 
     googleMap.addMarker(options); 
     String url = getMapsApiDirectionsUrl(); 
     ReadTask downloadTask = new ReadTask(); 
     downloadTask.execute(url); 

     googleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(BROOKLYN_BRIDGE, 
       13)); 
     addMarkers(); 

    } 

    private String getMapsApiDirectionsUrl() { 
     String waypoints = "waypoints=optimize:true|" 
       + LOWER_MANHATTAN.latitude + "," + LOWER_MANHATTAN.longitude 
       + "|" + "|" + BROOKLYN_BRIDGE.latitude + "," 
       + BROOKLYN_BRIDGE.longitude + "|" + WALL_STREET.latitude + "," 
       + WALL_STREET.longitude; 

     String sensor = "sensor=false"; 
     String params = waypoints + "&" + sensor; 
     String output = "json"; 
     String url = "https://maps.googleapis.com/maps/api/directions/" 
       + output + "?" + params; 
     return url; 
    } 

    private void addMarkers() { 
     if (googleMap != null) { 
      googleMap.addMarker(new MarkerOptions().position(BROOKLYN_BRIDGE) 
        .title("First Point")); 
      googleMap.addMarker(new MarkerOptions().position(LOWER_MANHATTAN) 
        .title("Second Point")); 
      googleMap.addMarker(new MarkerOptions().position(WALL_STREET) 
        .title("Third Point")); 
     } 
    } 

    private class ReadTask extends AsyncTask<String, Void, String> { 
     @Override 
     protected String doInBackground(String... url) { 
      String data = ""; 
      try { 
       HttpConnection http = new HttpConnection(); 
       data = http.readUrl(url[0]); 
      } catch (Exception e) { 
       Log.d("Background Task", e.toString()); 
      } 
      return data; 
     } 

     @Override 
     protected void onPostExecute(String result) { 
      super.onPostExecute(result); 
      new ParserTask().execute(result); 
     } 
    } 

    private class ParserTask extends 
      AsyncTask<String, Integer, List<List<HashMap<String, String>>>> { 

     @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]); 
       PathJSONParser parser = new PathJSONParser(); 
       routes = parser.parse(jObject); 
      } catch (Exception e) { 
       e.printStackTrace(); 
      } 
      return routes; 
     } 

     @Override 
     protected void onPostExecute(List<List<HashMap<String, String>>> routes) { 
      ArrayList<LatLng> points = null; 
      PolylineOptions polyLineOptions = null; 

      // traversing through routes 
      for (int i = 0; i < routes.size(); i++) { 
       points = new ArrayList<LatLng>(); 
       polyLineOptions = new PolylineOptions(); 
       List<HashMap<String, String>> path = routes.get(i); 

       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); 
       } 

       polyLineOptions.addAll(points); 
       polyLineOptions.width(2); 
       polyLineOptions.color(Color.BLUE); 
      } 

      googleMap.addPolyline(polyLineOptions); 
     } 
    } 
}

要得到指示路径的方向，我使用了Google Directions API。我们只需使用HTTP请求命中给定的URL并获得json响应。此Google服务会计算给定位置之间的方向。

import java.io.BufferedReader; 
import java.io.IOException; 
import java.io.InputStream; 
import java.io.InputStreamReader; 
import java.net.HttpURLConnection; 
import java.net.URL; 

import android.util.Log; 

public class HttpConnection { 
    public String readUrl(String mapsApiDirectionsUrl) throws IOException { 
     String data = ""; 
     InputStream iStream = null; 
     HttpURLConnection urlConnection = null; 
     try { 
      URL url = new URL(mapsApiDirectionsUrl); 
      urlConnection = (HttpURLConnection) url.openConnection(); 
      urlConnection.connect(); 
      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 reading url", e.toString()); 
     } finally { 
      iStream.close(); 
      urlConnection.disconnect(); 
     } 
     return data; 
    } 

}

这最后一堂课jasonparser西港岛线让你的方向

import java.util.ArrayList; 
import java.util.HashMap; 
import java.util.List; 

import org.json.JSONArray; 
import org.json.JSONException; 
import org.json.JSONObject; 

import com.google.android.gms.maps.model.LatLng; 

public class PathJSONParser { 

    public List<List<HashMap<String, String>>> parse(JSONObject jObject) { 
     List<List<HashMap<String, String>>> routes = new ArrayList<List<HashMap<String, String>>>(); 
     JSONArray jRoutes = null; 
     JSONArray jLegs = null; 
     JSONArray jSteps = null; 
     try { 
      jRoutes = jObject.getJSONArray("routes"); 
      /** Traversing all 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++) { 
        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<String, String>(); 
          hm.put("lat", 
            Double.toString(((LatLng) list.get(l)).latitude)); 
          hm.put("lng", 
            Double.toString(((LatLng) list.get(l)).longitude)); 
          path.add(hm); 
         } 
        } 
        routes.add(path); 
       } 
      } 

     } catch (JSONException e) { 
      e.printStackTrace(); 
     } catch (Exception e) { 
     } 
     return routes; 
    } 

    /** 
    * Method Courtesy : 
    * 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<LatLng>(); 
     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; 
    } 
}

XmaI和manifestfiles是否有以下

activity_path_google_map.xml 
<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" 
    tools:context=".TaskRoadMap" > 

    <fragment 
     android:id="@+id/map" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     class="com.google.android.gms.maps.SupportMapFragment"/> 

</RelativeLayout>

您有权限manifest资源配置文件

AndroidManifest.xml 

<?xml version="1.0" encoding="utf-8"?> 
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
    package="com.javapapers.android.maps.path" 
    android:versionCode="1" 
    android:versionName="1.0" > 

    <uses-sdk 
     android:minSdkVersion="8" 
     android:targetSdkVersion="18" /> 

    <permission 
     android:name="com.javapapers.android.maps.path.permission.MAPS_RECEIVE" 
     android:protectionLevel="signature" /> 

    <uses-permission android:name="com.javapapers.android.maps.path.permission.MAPS_RECEIVE" /> 
    <uses-permission android:name="android.permission.INTERNET" /> 
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /> 
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /> 
    <uses-permission android:name="com.google.android.providers.gsf.permission.READ_GSERVICES" /> 
    <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" /> 
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" /> 

    <uses-feature 
     android:glEsVersion="0x00020000" 
     android:required="true" /> 

    <application 
     android:allowBackup="true" 
     android:icon="@drawable/ic_launcher" 
     android:label="@string/app_name" 
     android:theme="@style/AppTheme" > 
     <activity 
      android:name="com.javapapers.android.maps.path.PathGoogleMapActivity" 
      android:label="@string/title_activity_path_google_map" > 
      <intent-filter> 
       <action android:name="android.intent.action.MAIN" /> 

       <category android:name="android.intent.category.LAUNCHER" /> 
      </intent-filter> 
     </activity> 

     <meta-data 
      android:name="com.google.android.maps.v2.API_KEY" 
      android:value="AIzaSyARCTcX8bABCDE_ohscNcALAak-HnjTO5s" /> 

     <meta-data 
      android:name="com.google.android.gms.version" 
      android:value="@integer/google_play_services_version" /> 

    </application> 

</manifest>

来源

2015-10-21 04:34:54

Android - 在谷歌地图上显示方向

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