Flex 3 Mobile- Basic Map Enhanced GPS error

MikeDahm — Sun, 12 Dec 2021 16:00:04 GMT

I am just starting out on my first mobile application and upgraded from Flex 2.5 to 3. I was using some of the code from the Basic Map Enhanced GPS made by TOVernon to show current location reprojected to the map coordinates. The code worked great in Flex 2.5. When upgrading from Flex 2.5 to 3 I get an error in the geolocation event listener.

I get the following errors:
Multiple markers at this line:
-1067: Implicit coercion of a value of type Array to an unrelated type com.esri.ags.tasks.supportClasses:ProjectParameters.
-1067: Implicit coercion of a value of type com.esri.ags:SpatialReference to an unrelated type mx.rpc:IResponder.

   <fx:Script>
  <![CDATA[
   import com.esri.ags.Graphic;
   import com.esri.ags.events.ExtentEvent;
   import com.esri.ags.events.GeometryServiceEvent;
   import com.esri.ags.events.MapEvent;
   import com.esri.ags.geometry.Geometry;
   import com.esri.ags.geometry.MapPoint;
   import com.esri.ags.geometry.Polygon;
   import com.esri.ags.symbols.PictureMarkerSymbol;
   import com.esri.ags.tasks.supportClasses.BufferParameters;
   import com.esri.ags.utils.WebMercatorUtil;
      
   import flash.sensors.Geolocation;
   
   [Embed(source="/assets/gpsA.png")]
   private var m_gpsA:Class;
   [Embed(source="/assets/gpsB.png")]
   private var m_gpsB:Class;
   
   private var GPSPoint:MapPoint;  
   private var pt:MapPoint;
   private var geo:Geolocation;
   
   //Load GPS icon if GPS is present
   protected function myMap_loadHandler(event:MapEvent):void
   {
    if (Geolocation.isSupported==true)
    {
     //Initialize the location sensor.
     geo = new Geolocation;
     //set update interval
     geo.setRequestedUpdateInterval(5000);
     //add GPS toggle button
     zoomToCurrentLocationImg.source = m_gpsA;
     zoomToCurrentLocationImg.visible = true;
    }
    else
    {
     //do not show a GPS Icon
    }
   }
   //activate the GPS
   protected function locateGPS(event:MouseEvent):void
   {
    if (myGraphicsLayer.numGraphics > 0)
    {
     myGraphicsLayer.clear();
     GPSGraphicsLayer.clear();
     accBorder.visible = false;
     zoomToCurrentLocationImg.source = m_gpsA;
     geo.removeEventListener(GeolocationEvent.UPDATE, onUpdate);
    }
    else
    {
     zoomToCurrentLocationImg.source = m_gpsB;
     geo.addEventListener(GeolocationEvent.UPDATE, onUpdate);
    }
   }
   
   //geolocation event listener  
   private function onUpdate(event:GeolocationEvent):void 
   { 
    var long:String = event.longitude.toString();
    var lat:String = event.latitude.toString();
    var ha:Number = event.horizontalAccuracy;
    accText.text = ha.toString();
    var longnew:Number = Number(long);
    var latnew:Number = Number(lat);
    var GPSPoint:MapPoint = new MapPoint(longnew, latnew);
    GPSPoint.spatialReference = new SpatialReference(4326); 
    var outSR:SpatialReference = myMap.spatialReference;    
    geometryService.project([GPSPoint as Geometry], outSR); 
   } 
   
   //reproject event 
   private function projectCompleteHandler(event:GeometryServiceEvent):void
   { 
    try
    {
     // Note: As of version 2.0, GeometryService returns geometries (instead of graphics)      
     var pt:MapPoint = (event.result as Array)[0]as MapPoint;
     var ptGraphic:Graphic = new Graphic(null,GPSicon);
     ptGraphic.geometry = pt; 
     myGraphicsLayer.clear()
     GPSGraphicsLayer.clear()
     accBorder.visible = true;
     myGraphicsLayer.add(ptGraphic);
     //add buffer code for GPS horizontal accuracy
     var bufferParameters:BufferParameters = new BufferParameters();
     bufferParameters.geometries = [ pt ];
     bufferParameters.distances = [ accText.text ];
     bufferParameters.unit = GeometryService.UNIT_FOOT;
     bufferParameters.bufferSpatialReference = myMap.spatialReference;
     bufferParameters.outSpatialReference = myMap.spatialReference;     
     geometryService.addEventListener(GeometryServiceEvent.BUFFER_COMPLETE, bufferCompleteHandler);
     geometryService.buffer(bufferParameters);     
     function bufferCompleteHandler(event:GeometryServiceEvent):void
     {
      geometryService.removeEventListener(GeometryServiceEvent.BUFFER_COMPLETE, bufferCompleteHandler);
      // Note: As of version 2.0, GeometryService returns geometries (instead of graphics)
      for each (var geometry:Polygon in event.result)
      {
       var graphic:Graphic = new Graphic();
       graphic.geometry = geometry;
       graphic.symbol = fillSymbol;
       GPSGraphicsLayer.add(graphic);
      }
     }
     if (zoomToCurrentLocationImg.source == m_gpsB)
     {
      myMap.centerAt(pt)
     }     
     else
     {
      //  geo.removeEventListener(GeolocationEvent.UPDATE, onUpdate);
      //  myGraphicsLayer.clear();
      GPSGraphicsLayer.clear();
     }      
    }
    catch (error:Error)
    {
     //Alert.show(error.toString());
    }
   } 
  ]]>
 </fx:Script>
 
 <fx:Declarations>
  <!--GPS accuracy Polygon-->
  <esri:SimpleFillSymbol id="fillSymbol" color="0x81BEF7"  alpha=".5">
   <esri:outline>
    <esri:SimpleLineSymbol width="2" color="0x0040FF"/>
   </esri:outline>
  </esri:SimpleFillSymbol>
  <!--GPS icon-->
  <esri:PictureMarkerSymbol  id="GPSicon" source="@Embed(source='assets/gps.png')"/>
  <s:Fade id="fade" alphaFrom="1"  alphaTo="0" duration="1500"/>
  <esri:GeometryService id="geometryService" showBusyCursor="false" projectComplete="projectCompleteHandler(event)"  
         url="http://sampleserver3.arcgisonline.com/ArcGIS/rest/services/Geometry/GeometryServer"/>
 </fx:Declarations>

Any help would be greatly appreciated.

Re: Flex 3 Mobile- Basic Map Enhanced GPS error

RobertScheitlin__GISP — Fri, 13 Jul 2012 14:26:00 GMT

Mike,

The issue is simplly the result of API changes from 2.5 to 3.0 that are documented in the whats new section of the API.
You need to add this import:

import com.esri.ags.tasks.supportClasses.ProjectParameters

and update this function:

            //geolocation event listener                     private function onUpdate(event:GeolocationEvent):void              {                  var long:String = event.longitude.toString();                 var lat:String = event.latitude.toString();                 var ha:Number = event.horizontalAccuracy;                 accText.text = ha.toString();                 var longnew:Number = Number(long);                 var latnew:Number = Number(lat);                 var GPSPoint:MapPoint = new MapPoint(longnew, latnew);                 GPSPoint.spatialReference = new SpatialReference(4326);                     var projParams:ProjectParameters = new ProjectParameters();                 projParams.geometries = [GPSPoint];                 projParams.outSpatialReference = myMap.spatialReference;                 geometryService.project(projParams);             }

Don't forget to click the Mark as answer check on this post and to click the top arrow (promote).
Follow the steps as shown in the below graphic:

Re: Flex 3 Mobile- Basic Map Enhanced GPS error

MikeDahm — Fri, 10 Dec 2021 23:10:47 GMT

Solved my own problem. Flex 3 treats the geometry service differently. Changed the following code:

  //geolocation event listener  
   private function onUpdate(event:GeolocationEvent):void 
   { 
    var long:String = event.longitude.toString();
    var lat:String = event.latitude.toString();
    var ha:Number = event.horizontalAccuracy;
    accText.text = ha.toString();
    var longnew:Number = Number(long);
    var latnew:Number = Number(lat);
    var GPSPoint:MapPoint = new MapPoint(longnew, latnew);
    GPSPoint.spatialReference = new SpatialReference(4326); 
    var outSR:SpatialReference = myMap.spatialReference; 
    const projectParameters:ProjectParameters = new ProjectParameters;
    projectParameters.geometries = [ GPSPoint as Geometry ];
    projectParameters.outSpatialReference = outSR;
    geometryService.project(projectParameters);
    

   }

Re: Flex 3 Mobile- Basic Map Enhanced GPS error

MikeDahm — Fri, 13 Jul 2012 14:37:15 GMT

Thanks, I just found the reference to the change in the geometry service. Fixed it a bit different but your code was a little cleaner. Thank you very much.

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