离子2如何实现送货服务项目的方向

Question

在此代码中，我尝试添加direction：

public  directionsService : any; //= new google.maps.DirectionsService;
public directionsDisplay : any;// = new google.maps.DirectionsRenderer;
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initializeMap() {
  this.directionsService = new google.maps.DirectionsService;
  this.directionsDisplay = new google.maps.DirectionsRenderer;

  let minZoomLevel = 14;
  Geolocation.getCurrentPosition().then((position) => {
  this.map = new google.maps.Map(document.getElementById('map_canvas'), {
  zoom: minZoomLevel,
  center: new google.maps.LatLng(position.coords.latitude, position.coords.longitude),
  mapTypeControl: false,
  streetViewControl: false,
  disableDefaultUI: true,
  mapTypeId: google.maps.MapTypeId.ROADMAP
});
var trafficLayer = new google.maps.TrafficLayer();
        trafficLayer.setMap(this.map);
  });
  this.directionsDisplay.setMap(this.map);
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calculateAndDisplayRoute(directionsService, directionsDisplay) {
origin
   console.log('here Iam');
        directionsService.route({
          origin: ,
          destination: this.tLastLat+','+this.tLastLng,
          travelMode: 'DRIVING'
        }, function(response, status) {
          if (status === 'OK') {
            directionsDisplay.setDirections(response);
          } else {
            window.alert('Directions request failed due to ' + status);
          }
        });
}