2017-03-31 8 views
0

私のアプリは、現在の位置にピンを落とさないことを除いてすべてを完全に行います。私はまた、ピンが画面上にとどまり、その場所が変更されたときにその実行中および新しいピンがドロップされるようにする必要があります。私のコードは以下の通りです。Googleマップで位置が変更されたときにピン(マーカー)を落として新しいピンを落とす方法

public class MainActivity extends AppCompatActivity 
     implements OnMapReadyCallback, 
     GoogleApiClient.ConnectionCallbacks, 
     GoogleApiClient.OnConnectionFailedListener, 
     LocationListener { 

    GoogleMap mGoogleMap; 
    SupportMapFragment mapFrag; 
    LocationRequest mLocationRequest; 
    GoogleApiClient mGoogleApiClient; 
    Location mLastLocation; 
    Marker mCurrLocationMarker; 
    private ArrayList<Location> locations = new ArrayList<Location>(); 

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

     getSupportActionBar().setTitle("Map"); 

     mapFrag = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map); 
     mapFrag.getMapAsync(this); 
     TextView textView = (TextView) findViewById(R.id.textView); 
    } 

    @Override 
    public void onPause() { 
     super.onPause(); 

     //stop location updates when Activity is no longer active 
     if (mGoogleApiClient != null) { 
      LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this); 
     } 
    } 

    @Override 
    public void onMapReady(GoogleMap googleMap) 
    { 
     mGoogleMap=googleMap; 
     mGoogleMap.setMapType(GoogleMap.MAP_TYPE_HYBRID); 

     //Initialize Google Play Services 
     if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) { 
      if (ContextCompat.checkSelfPermission(this, 
        Manifest.permission.ACCESS_FINE_LOCATION) 
        == PackageManager.PERMISSION_GRANTED) { 
       //Location Permission already granted 
       buildGoogleApiClient(); 
       mGoogleMap.setMyLocationEnabled(true); 
      } else { 
       //Request Location Permission 
       checkLocationPermission(); 
      } 
     } 
     else { 
      buildGoogleApiClient(); 
      mGoogleMap.setMyLocationEnabled(true); 
     } 
    } 

    protected synchronized void buildGoogleApiClient() { 
     mGoogleApiClient = new GoogleApiClient.Builder(this) 
       .addConnectionCallbacks(this) 
       .addOnConnectionFailedListener(this) 
       .addApi(LocationServices.API) 
       .build(); 
     mGoogleApiClient.connect(); 
    } 

    @Override 
    public void onConnected(Bundle bundle) { 
     mLocationRequest = new LocationRequest(); 
     mLocationRequest.setInterval(1000); 
     mLocationRequest.setFastestInterval(1000); 
     mLocationRequest.setPriority(LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY); 
     if (ContextCompat.checkSelfPermission(this, 
       Manifest.permission.ACCESS_FINE_LOCATION) 
       == PackageManager.PERMISSION_GRANTED) { 
      LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this); 
     } 
    } 

    @Override 
    public void onConnectionSuspended(int i) {} 

    @Override 
    public void onConnectionFailed(ConnectionResult connectionResult) {} 

    @Override 
    public void onLocationChanged(Location location) 
    { 

     if (mCurrLocationMarker != null) { 
      mCurrLocationMarker.remove(); 
      LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude()); 
      MarkerOptions markerOptions = new MarkerOptions(); 
      markerOptions.position(latLng); 
      markerOptions.title("Current Position"); 
      markerOptions.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_MAGENTA)); 
      mGoogleMap.addMarker(new MarkerOptions() 
          .position(new LatLng(location.getLatitude(), location.getLongitude()))); 

      //move map camera 
      mGoogleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(latLng,11)); 

      //optionally, stop location updates if only current location is needed 
      if (mGoogleApiClient != null) { 
       LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this); 
      } 
     } 


     double latitude = location.getLatitude(); 
     double longitude = location.getLongitude(); 
     double speed = location.getSpeed(); 
     double distance = 0; 
     locations.add(location); 
     for(int i = 0; i < locations.size()-1; i++) { 
      distance += locations.get(i).distanceTo(locations.get(i +1)); 
     } 

     StringBuilder stBuilder = new StringBuilder(); 
     stBuilder.append(" Latitude: "); 
     stBuilder.append(latitude); 
     stBuilder.append("\n"); 
     stBuilder.append(" Logitude: "); 
     stBuilder.append(longitude); 
     stBuilder.append("\n"); 
     stBuilder.append(" Speed: "); 
     stBuilder.append(speed +"\t"); 

     stBuilder.append("Distance: "); 
     stBuilder.append(distance + " km"); 
     TextView textView = (TextView) findViewById(R.id.textView); 
     textView.setText(stBuilder); 


     //Place current location marker 

    } 

    public static final int MY_PERMISSIONS_REQUEST_LOCATION = 99; 
    private void checkLocationPermission() { 
     if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) 
       != PackageManager.PERMISSION_GRANTED) { 

      // Should we show an explanation? 
      if (ActivityCompat.shouldShowRequestPermissionRationale(this, 
        Manifest.permission.ACCESS_FINE_LOCATION)) { 

       // Show an explanation to the user *asynchronously* -- don't block 
       // this thread waiting for the user's response! After the user 
       // sees the explanation, try again to request the permission. 
       new AlertDialog.Builder(this) 
         .setTitle("Location Permission Needed") 
         .setMessage("This app needs the Location permission, please accept to use location functionality") 
         .setPositiveButton("OK", new DialogInterface.OnClickListener() { 
          @Override 
          public void onClick(DialogInterface dialogInterface, int i) { 
           //Prompt the user once explanation has been shown 
           ActivityCompat.requestPermissions(MainActivity.this, 
             new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 
             MY_PERMISSIONS_REQUEST_LOCATION); 
          } 
         }) 
         .create() 
         .show(); 


      } else { 
       // No explanation needed, we can request the permission. 
       ActivityCompat.requestPermissions(this, 
         new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, 
         MY_PERMISSIONS_REQUEST_LOCATION); 
      } 
     } 
    } 

    @Override 
    public void onRequestPermissionsResult(int requestCode, 
              String permissions[], int[] grantResults) { 
     switch (requestCode) { 
      case MY_PERMISSIONS_REQUEST_LOCATION: { 
       // If request is cancelled, the result arrays are empty. 
       if (grantResults.length > 0 
         && grantResults[0] == PackageManager.PERMISSION_GRANTED) { 

        // permission was granted, yay! Do the 
        // location-related task you need to do. 
        if (ContextCompat.checkSelfPermission(this, 
          Manifest.permission.ACCESS_FINE_LOCATION) 
          == PackageManager.PERMISSION_GRANTED) { 

         if (mGoogleApiClient == null) { 
          buildGoogleApiClient(); 
         } 
         mGoogleMap.setMyLocationEnabled(true); 
        } 

       } else { 

        // permission denied, boo! Disable the 
        // functionality that depends on this permission. 
        Toast.makeText(this, "permission denied", LENGTH_LONG).show(); 
       } 
       return; 
      } 

      // other 'case' lines to check for other 
      // permissions this app might request 
     } 
    } 

} 

答えて

0

はそこに既に存在した場合にのみマーカーを除去し、またaddMarker()メソッドの戻り値にマーカーの参照を割り当てます。

また、現在地の監視を継続したい場合は、場所の更新を削除しないでください。

また、あなたはすでにオブジェクトを設定MarkerOptionsを持っているので、そのいずれかを使用します。

@Override 
public void onLocationChanged(Location location) { 

    //Only remove previous marker here 
    if (mCurrLocationMarker != null) { 
     mCurrLocationMarker.remove(); 
    } 

    //This stuff is executed every time: 
    LatLng latLng = new LatLng(location.getLatitude(), location.getLongitude()); 
    MarkerOptions markerOptions = new MarkerOptions(); 
    markerOptions.position(latLng); 
    markerOptions.title("Current Position"); 
    markerOptions.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_MAGENTA)); 

    //Assign Marker reference here: 
    mCurrLocationMarker = mGoogleMap.addMarker(markerOptions); 

    //move map camera 
    mGoogleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(latLng,11)); 

    //optionally, stop location updates if only current location is needed 
    /* remove this: 
    if (mGoogleApiClient != null) { 
     LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this); 
    } 
    */ 

    //The rest can stay as is........ 

} 
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