Selected feature is not displaying in Graphics Layer

GirishSomesh

Hi All,

I have to display an Active hurricane on a Graphiclayer on change of dropdownlist.
Below is the code, I am not sure where i am going wrong can any one help me out.

private void ActiveCurentLocation()
         {
             string oAQUrl = "http://esrilabs1.esri.com/ArcGIS/rest/services/LiveFeeds/Hurricane_Active/MapServer/0";
             QueryTask AQExeQueryTaskActivelocation = new QueryTask(oAQUrl);
             AQExeQueryTaskActivelocation.ExecuteCompleted += AQExeQueryTaskActivelocation_ExecuteCompleted;
             ESRI.ArcGIS.Client.Tasks.Query query = new ESRI.ArcGIS.Client.Tasks.Query();
             string querytext = "STORMNAME='PHILLIPPE'";// + strActiveH + "'";// +"' AND FCSTPRD = 120";//PHILLIPPE' AND FCSTPRD = 120";//PHILLIPPE//HILARY
             query.Text = querytext;
             query.Where = querytext;
             query.OutFields.Add("*");
             query.ReturnGeometry = true;
             AQExeQueryTaskActivelocation.ExecuteAsync(query);
         }

void AQExeQueryTaskActivelocation_ExecuteCompleted(object sender, ESRI.ArcGIS.Client.Tasks.QueryEventArgs args)
         {
             FeatureSet featureSet = args.FeatureSet;
             GraphicsLayer graphicsLayer = MyMap.Layers["MyGraphicsLayer"] as GraphicsLayer;
    graphicsLayer.Visible=true;
             graphicsLayer.Initialized += new EventHandler<EventArgs>(MyGraphicsLayer_Initialized);
             if (featureSet != null && featureSet.Features.Count > 0)
             {
                int oCount = featureSet.Features.Count;
    Graphic selectedFeature = featureSet.Features[0];
    selectedFeature.Symbol=PushpinSymbol;
                graphicsLayer.Visible = true;
                selectedFeature.Selected = true;
                graphicsLayer.Refresh();
                graphicsLayer.Graphics.Add(selectedFeature);

             }
             else
             {

             }
         }

private void MyGraphicsLayer_Initialized(object sender, EventArgs args)
         {

         }

XMAL CODE:
<esriSymbols:PictureMarkerSymbol x:Name="PushpinSymbol" OffsetX="11" OffsetY="39" Height="30" Width="25" Source="Images/i_pushpin.png" />

<esri:GraphicsLayer ID="MyGraphicsLayer"  Visible="True"></esri:GraphicsLayer>


Thanks.

HugoCardenas

This line in your "AQExeQueryTaskActivelocation_ExecuteCompleted" event handler would throw a similar exception if features are not returned:

FeatureSet featureSet = args.FeatureSet;

I would use (in this scenario):

if (args.FeatureSet== null) return;

Then, I would issue:

FeatureSet featureSet = args.FeatureSet;

Also, I would define the "Failed", besides ExecuteCompleted,  event handler as well to check if another cause is procducing the exception.

Hugo.