问如何在Google Maps API中沿原点和目的地之间的路线获取地点(例如加油站)

EN

var directionsDisplay;
var directionsService = new google.maps.DirectionsService();
var map;
var haight = new google.maps.LatLng(49.216364,-122.811897);
var oceanBeach = new google.maps.LatLng(50.131446,-119.506838);

function initialize() {
  directionsDisplay = new google.maps.DirectionsRenderer();
  var mapOptions = {
  zoom: 14,
  mapTypeId: google.maps.MapTypeId.ROADMAP,
  center: haight
}
  map = new google.maps.Map(document.getElementById('map-canvas'), mapOptions);
  directionsDisplay.setMap(map);

    calcRoute();
 }

function calcRoute() {
  var request = {
  origin: haight,
  destination: oceanBeach,
  travelMode: google.maps.TravelMode.DRIVING
  };
  directionsService.route(request, function(response, status) {
   if (status == google.maps.DirectionsStatus.OK) {
       directionsDisplay.setDirections(response);
      }
 });
}

google.maps.event.addDomListener(window, 'load', initialize);

// Make the directions request
  directionService.route(request, function(result, status) {
    if (status == google.maps.DirectionsStatus.OK) {
      directionsRenderer.setDirections(result);

      // Box around the overview path of the first route
      var path = result.routes[0].overview_path;
      var boxes = routeBoxer.box(path, distance);
      drawBoxes(boxes);
    } else {
      alert("Directions query failed: " + status);
    }

      for (var i = 0; i < boxes.length; i++) {
  var bounds = box[i];
  // Perform search over this bounds 
}



  });
}