機器人：如何繪製航線方向谷歌地圖API V2從當前位置到目的地

Question

如何從當前的位置繪製航線方向到目的地，其中（緯度和經度），我有代碼如下：

import android.os.Bundle; 
import com.actionbarsherlock.app.SherlockActivity; 

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

public class DetailMapActivity extends SherlockActivity { 
    private GoogleMap map; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main_detail_map); 

     LatLng TO_DESTINATION = new LatLng(-6.33438, 106.74316); 

     map = ((MapFragment) getFragmentManager().findFragmentById(R.id.map)) 
       .getMap(); 
     map.setMyLocationEnabled(true); 

     map.addMarker(new MarkerOptions().position(TO_DESTINATION).title("Destination Title") 
       .snippet("Destination Description")); 

     map.moveCamera(CameraUpdateFactory.newLatLngZoom(TO_LOCATION, 40)); 

     map.animateCamera(CameraUpdateFactory.zoomTo(10), 2000, null); 
    } 
} 

我想通過提供商網絡或gps從當前位置提取，然後通過開車到目的地來繪製路線。

我正在使用android google apis V2。

感謝您的幫助。

Answer 1

這對我的偉大工程：
這不是我的代碼，我把它從計算器一個偉大的答案，但現在我不能找到這個答案，所以這裏是代碼：

這個類添加到項目中：

package ...; 

import java.io.InputStream; 
import java.util.ArrayList; 

import javax.xml.parsers.DocumentBuilder; 
import javax.xml.parsers.DocumentBuilderFactory; 

import org.apache.http.HttpResponse; 
import org.apache.http.client.HttpClient; 
import org.apache.http.client.methods.HttpPost; 
import org.apache.http.impl.client.DefaultHttpClient; 
import org.apache.http.protocol.BasicHttpContext; 
import org.apache.http.protocol.HttpContext; 
import org.w3c.dom.Document; 
import org.w3c.dom.Node; 
import org.w3c.dom.NodeList; 

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

import android.content.Context; 
import android.util.Log; 

public class GMapV2Direction { 
    public final static String MODE_DRIVING = "driving"; 
    public final static String MODE_WALKING = "walking"; 

    public GMapV2Direction() { 
    } 

    public Document getDocument(LatLng start, LatLng end, String mode) { 
     String url = "http://maps.googleapis.com/maps/api/directions/xml?" 
       + "origin=" + start.latitude + "," + start.longitude 
       + "&destination=" + end.latitude + "," + end.longitude 
       + "&sensor=false&units=metric&mode=driving"; 
     Log.d("url", url); 
     try { 
      HttpClient httpClient = new DefaultHttpClient(); 
      HttpContext localContext = new BasicHttpContext(); 
      HttpPost httpPost = new HttpPost(url); 
      HttpResponse response = httpClient.execute(httpPost, localContext); 
      InputStream in = response.getEntity().getContent(); 
      DocumentBuilder builder = DocumentBuilderFactory.newInstance() 
        .newDocumentBuilder(); 
      Document doc = builder.parse(in); 
      return doc; 
     } catch (Exception e) { 
      e.printStackTrace(); 
     } 
     return null; 
    } 

    public String getDurationText(Document doc) { 
     try { 

      NodeList nl1 = doc.getElementsByTagName("duration"); 
      Node node1 = nl1.item(0); 
      NodeList nl2 = node1.getChildNodes(); 
      Node node2 = nl2.item(getNodeIndex(nl2, "text")); 
      Log.i("DurationText", node2.getTextContent()); 
      return node2.getTextContent(); 
     } catch (Exception e) { 
      return "0"; 
     } 
    } 

    public int getDurationValue(Document doc) { 
     try { 
      NodeList nl1 = doc.getElementsByTagName("duration"); 
      Node node1 = nl1.item(0); 
      NodeList nl2 = node1.getChildNodes(); 
      Node node2 = nl2.item(getNodeIndex(nl2, "value")); 
      Log.i("DurationValue", node2.getTextContent()); 
      return Integer.parseInt(node2.getTextContent()); 
     } catch (Exception e) { 
      return -1; 
     } 
    } 

    public String getDistanceText(Document doc) { 
     /* 
     * while (en.hasMoreElements()) { type type = (type) en.nextElement(); 
     * 
     * } 
     */ 

     try { 
      NodeList nl1; 
      nl1 = doc.getElementsByTagName("distance"); 

      Node node1 = nl1.item(nl1.getLength() - 1); 
      NodeList nl2 = null; 
      nl2 = node1.getChildNodes(); 
      Node node2 = nl2.item(getNodeIndex(nl2, "value")); 
      Log.d("DistanceText", node2.getTextContent()); 
      return node2.getTextContent(); 
     } catch (Exception e) { 
      return "-1"; 
     } 

     /* 
     * NodeList nl1; if(doc.getElementsByTagName("distance")!=null){ nl1= 
     * doc.getElementsByTagName("distance"); 
     * 
     * Node node1 = nl1.item(nl1.getLength() - 1); NodeList nl2 = null; if 
     * (node1.getChildNodes() != null) { nl2 = node1.getChildNodes(); Node 
     * node2 = nl2.item(getNodeIndex(nl2, "value")); Log.d("DistanceText", 
     * node2.getTextContent()); return node2.getTextContent(); } else return 
     * "-1";} else return "-1"; 
     */ 
    } 

    public int getDistanceValue(Document doc) { 
     try { 
      NodeList nl1 = doc.getElementsByTagName("distance"); 
      Node node1 = null; 
      node1 = nl1.item(nl1.getLength() - 1); 
      NodeList nl2 = node1.getChildNodes(); 
      Node node2 = nl2.item(getNodeIndex(nl2, "value")); 
      Log.i("DistanceValue", node2.getTextContent()); 
      return Integer.parseInt(node2.getTextContent()); 
     } catch (Exception e) { 
      return -1; 
     } 
     /* 
     * NodeList nl1 = doc.getElementsByTagName("distance"); Node node1 = 
     * null; if (nl1.getLength() > 0) node1 = nl1.item(nl1.getLength() - 1); 
     * if (node1 != null) { NodeList nl2 = node1.getChildNodes(); Node node2 
     * = nl2.item(getNodeIndex(nl2, "value")); Log.i("DistanceValue", 
     * node2.getTextContent()); return 
     * Integer.parseInt(node2.getTextContent()); } else return 0; 
     */ 
    } 

    public String getStartAddress(Document doc) { 
     try { 
      NodeList nl1 = doc.getElementsByTagName("start_address"); 
      Node node1 = nl1.item(0); 
      Log.i("StartAddress", node1.getTextContent()); 
      return node1.getTextContent(); 
     } catch (Exception e) { 
      return "-1"; 
     } 

    } 

    public String getEndAddress(Document doc) { 
     try { 
      NodeList nl1 = doc.getElementsByTagName("end_address"); 
      Node node1 = nl1.item(0); 
      Log.i("StartAddress", node1.getTextContent()); 
      return node1.getTextContent(); 
     } catch (Exception e) { 
      return "-1";   
    } 
    } 
    public String getCopyRights(Document doc) { 
     try { 
      NodeList nl1 = doc.getElementsByTagName("copyrights"); 
      Node node1 = nl1.item(0); 
      Log.i("CopyRights", node1.getTextContent()); 
      return node1.getTextContent(); 
     } catch (Exception e) { 
     return "-1"; 
     } 

    } 

    public ArrayList<LatLng> getDirection(Document doc) { 
     NodeList nl1, nl2, nl3; 
     ArrayList<LatLng> listGeopoints = new ArrayList<LatLng>(); 
     nl1 = doc.getElementsByTagName("step"); 
     if (nl1.getLength() > 0) { 
      for (int i = 0; i < nl1.getLength(); i++) { 
       Node node1 = nl1.item(i); 
       nl2 = node1.getChildNodes(); 

       Node locationNode = nl2 
         .item(getNodeIndex(nl2, "start_location")); 
       nl3 = locationNode.getChildNodes(); 
       Node latNode = nl3.item(getNodeIndex(nl3, "lat")); 
       double lat = Double.parseDouble(latNode.getTextContent()); 
       Node lngNode = nl3.item(getNodeIndex(nl3, "lng")); 
       double lng = Double.parseDouble(lngNode.getTextContent()); 
       listGeopoints.add(new LatLng(lat, lng)); 

       locationNode = nl2.item(getNodeIndex(nl2, "polyline")); 
       nl3 = locationNode.getChildNodes(); 
       latNode = nl3.item(getNodeIndex(nl3, "points")); 
       ArrayList<LatLng> arr = decodePoly(latNode.getTextContent()); 
       for (int j = 0; j < arr.size(); j++) { 
        listGeopoints.add(new LatLng(arr.get(j).latitude, arr 
          .get(j).longitude)); 
       } 

       locationNode = nl2.item(getNodeIndex(nl2, "end_location")); 
       nl3 = locationNode.getChildNodes(); 
       latNode = nl3.item(getNodeIndex(nl3, "lat")); 
       lat = Double.parseDouble(latNode.getTextContent()); 
       lngNode = nl3.item(getNodeIndex(nl3, "lng")); 
       lng = Double.parseDouble(lngNode.getTextContent()); 
       listGeopoints.add(new LatLng(lat, lng)); 
      } 
     } 

     return listGeopoints; 
    } 

    private int getNodeIndex(NodeList nl, String nodename) { 
     for (int i = 0; i < nl.getLength(); i++) { 
      if (nl.item(i).getNodeName().equals(nodename)) 
       return i; 
     } 
     return -1; 
    } 

    private ArrayList<LatLng> decodePoly(String encoded) { 
     ArrayList<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 position = new LatLng((double) lat/1E5, (double) lng/1E5); 
      poly.add(position); 
     } 
     return poly; 
    } 
} 

然後使用這個類爲您的需求。
比如要繪製方向：

GMapV2Direction md = new GMapV2Direction(); 
mMap = ((SupportMapFragment) getSupportFragmentManager() 
        .findFragmentById(R.id.map)).getMap(); 
Document doc = md.getDocument(sourcePosition, destPosition, 
        GMapV2Direction.MODE_DRIVING); 

ArrayList<LatLng> directionPoint = md.getDirection(doc); 
      PolylineOptions rectLine = new PolylineOptions().width(3).color(
        Color.RED); 

      for (int i = 0; i < directionPoint.size(); i++) { 
       rectLine.add(directionPoint.get(i)); 
      } 
      Polyline polylin = mMap.addPolyline(rectLine); 

的sourcePosition, destPosition是從經緯度類型，你給他們想要的點。

我在這裏寫了我的代碼的部分，我認爲可以幫助，任何問題都歡迎。

Answer 2

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.main_detail_map); 
    ..... 
    ..... 

    /* Use the LocationManager class to obtain GPS locations */ 
    LocationManager mlocManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE); 

    LocationListener mlocListener = new MyLocationListener(); 
    mlocManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, mlocListener); 
} 

/* Class My Location Listener */ 
public class MyLocationListener implements LocationListener 
{ 

    @Override 
    public void onLocationChanged(Location loc) 
    { 
    CURRENT_LAT = loc.getLatitude(); 
    CURRENT_LNG = loc.getLongitude(); 
    } 

    @Override 
    public void onProviderDisabled(String provider) 
    { 
    Toast.makeText(getApplicationContext(), "Gps Disabled", Toast.LENGTH_SHORT).show(); 
    } 

    @Override 
    public void onProviderEnabled(String provider) 
    { 
    Toast.makeText(getApplicationContext(), "Gps Enabled", Toast.LENGTH_SHORT).show(); 
    } 

    @Override 
    public void onStatusChanged(String provider, int status, Bundle extras) 
    { 

    } 
} 

Answer 3

使用dvrm解決方案GMapV2Direction類，這是一個很好的解決方案，它仍然在工作，但現在您需要在新線程中實現getDocument方法以允許網絡連接。這是這個方法的AsyncTask的例子，其餘的類都是一樣的。您可以使用Handle處理它，或者實現自己的界面回調來獲得Docmuent xml響應。

public class GMapV2DirectionAsyncTask extends AsyncTask<String, Void, Document> { 

private final static String TAG = GMapV2DirectionAsyncTask.class.getSimpleName(); 
private Handler handler; 
private LatLng start, end; 
private String mode; 

public GMapV2DirectionAsyncTask(Handler handler, LatLng start, LatLng end, String mode) { 
    this.start = start; 
    this.end = end; 
    this.mode = mode; 
    this.handler = handler; 
} 

@Override 
protected Document doInBackground(String... params) { 

    String url = "http://maps.googleapis.com/maps/api/directions/xml?" 
      + "origin=" + start.latitude + "," + start.longitude 
      + "&destination=" + end.latitude + "," + end.longitude 
      + "&sensor=false&units=metric&mode=" + mode; 
    Log.d("url", url); 
    try { 
     HttpClient httpClient = new DefaultHttpClient(); 
     HttpContext localContext = new BasicHttpContext(); 
     HttpPost httpPost = new HttpPost(url); 
     HttpResponse response = httpClient.execute(httpPost, localContext); 
     InputStream in = response.getEntity().getContent(); 
     DocumentBuilder builder = DocumentBuilderFactory.newInstance() 
       .newDocumentBuilder(); 
     Document doc = builder.parse(in); 
     return doc; 
    } catch (Exception e) { 
     e.printStackTrace(); 
    } 
    return null; 
} 

@Override 
protected void onPostExecute(Document result) { 
    if (result != null) { 
     Log.d(TAG, "---- GMapV2DirectionAsyncTask OK ----"); 
     Message message = new Message(); 
     message.obj = result; 
     handler.dispatchMessage(message); 
    } else { 
     Log.d(TAG, "---- GMapV2DirectionAsyncTask ERROR ----"); 
    } 
} 

@Override 
protected void onPreExecute() { 
} 

@Override 
protected void onProgressUpdate(Void... values) { 
} 

}

這是該活動的異步處理方法：

protected void route(LatLng sourcePosition, LatLng destPosition, String mode) { 
    final Handler handler = new Handler() { 
     public void handleMessage(Message msg) { 
      try { 
       Document doc = (Document) msg.obj; 
       GMapV2Direction md = new GMapV2Direction(); 
       ArrayList<LatLng> directionPoint = md.getDirection(doc); 
       PolylineOptions rectLine = new PolylineOptions().width(15).color(getActivity().getResources().getColor(R.color.magoo_user_base_color)); 

       for (int i = 0; i < directionPoint.size(); i++) { 
        rectLine.add(directionPoint.get(i)); 
       } 
       Polyline polylin = googleMap.addPolyline(rectLine); 
       md.getDurationText(doc); 
      } catch (Exception e) { 
       e.printStackTrace(); 
      } 
     } 

    }; 

    new GMapV2DirectionAsyncTask(handler, sourcePosition, destPosition, GMapV2Direction.MODE_DRIVING).execute(); 
} 

還有一兩件事，如果持續時間值是錯誤的，因爲它的解決辦法是改變的一行GMapV2Direction類代碼：

Node node1 = nl1.item(nl1.getLength() - 1); 

代替：

Node node1 = nl1.item(0);