can't retrieve features on page load

Question

Hello everything is working fine but if i write the same code in page load then everytime i am getting null graphic if the same code i write in button click event i get fetures.below is code page load public Home() { InitializeComponent(); getprojects.projectsClient obj = new getprojects.projectsClient(); obj.GetRegionalRFPCompleted += new EventHandler(obj_GetRegionalRFPCompleted); obj.GetRegionalRFPAsync(); } and on button click getprojects.projectsClient obj = new getprojects.projectsClient(); obj.GetRegionalRFPCompleted += new EventHandler(obj_GetRegionalRFPCompleted); obj.GetRegionalRFPAsync(); void obj_GetRegionalRFPCompleted(object sender, getprojects.GetRegionalRFPCompletedEventArgs e) { Graphic g; Graphic ggl; for (int i = 0; i < e.Result.Count; i++) { g = new Graphic(); g.Symbol = LayoutRoot.Resources["DefaultpointSymbol"] as SimpleMarkerSymbol; FeatureLayer fl = MyMap.Layers["DynamicLayer"] as FeatureLayer; g = fl.Graphics.FirstOrDefault(g111 => (int)g111.Attributes["LOCATION_ID"] == int.Parse(e.Result.LOCATION_ID.ToString())); // g = fl.Graphics.FirstOrDefault(g111 => (int)g111.Attributes["LOCATION_ID"] == int.Parse("395")); if (g != null) { GraphicsLayer gl = MyMap.Layers["glayer"] as GraphicsLayer; ggl = new Graphic(); ggl.Geometry = g.Geometry; if (e.Result.PROJSTAT.ToString() == "F" || e.Result.PROJSTAT.ToString() == "P") ggl.Symbol = LayoutRoot.Resources["DefaultpointSymbol"] as SimpleMarkerSymbol; else ggl.Symbol = LayoutRoot.Resources["esriDefaultMarker_40"] as MarkerSymbol; MyMap.PanTo(ggl.Geometry); gl.Graphics.Add(ggl); } } } please let me know i want to load the graphics on page load not on button click event.. Thanks Foram

DominiqueBroux · Answer

You didn't hook up the Initialized handler to the right layer.

From your code:
FeatureLayer fl = MyMap.Layers["polygonlayer"] as FeatureLayer;

looks like your handler needs the "polygonlayer" to be initialized but you hook up your handler to "dynamiclayer" --> should be to "polygonlayer"

If your code needs more than one layer to be initialized, you can also hook up your handler to Map.Layers.LayersInitialized event. This event is fired when all layers of the map are initialized.

ForamParikh · Answer

I don't know why but i write everything again and check everything again now i am using query and everything is working fine on button click event but on page load I am not getting any features below is my xmal code on ------------------------------- private void FeatureLayer_Initialized(object sender, EventArgs e) { MessageBox.Show((sender as FeatureLayer).Graphics.Count.ToString()); QueryTask queryTask = new QueryTask("http://pipelineforthefuture.org/ArcGIS/rest/services/GIC4/polyjoint/MapServer/1"); queryTask.ExecuteCompleted += QueryTask_ExecuteCompleted; queryTask.Failed += QueryTask_Failed; ESRI.ArcGIS.Client.Tasks.Query query = new ESRI.ArcGIS.Client.Tasks.Query(); //query.Where = "GIC4.DBO.PROJECT_INFO.PROJECT_ID > 275"; query.Where = "1=1"; query.OutFields.Add("*"); queryTask.ExecuteAsync(query); } ----------------------------------------------- FeatureSet featureSet = args.FeatureSet; Graphic g; Graphic ggl; if (featureSet != null && featureSet.Features.Count > 0) { //QueryDetailsDataGrid.ItemsSource = featureSet.Features; //_pagedProductsView = new PagedCollectionView(featureSet.Features.ToList()); //_pagedProductsView.GroupDescriptions.Add(new PropertyGroupDescription("GIC4.DBO.PROJECT_INFO.PROJSTAT")); //QueryDetailsDataGrid.ItemsSource = _pagedProductsView; PagedCollectionView itemListView = new PagedCollectionView(featureSet); itemListView.SortDescriptions.Add(new System.ComponentModel.SortDescription("Attributes[GIC4.DBO.PROJECT_INFO.PROJ_NAME]", System.ComponentModel.ListSortDirection.Ascending)); //itemListView.GroupDescriptions.Add(new PropertyGroupDescription("Attributes[GIC4.DBO.PROJECT_INFO.PROJSTAT]")); QueryDetailsDataGrid.ItemsSource = itemListView; IList gsort = featureSet.Features.OrderBy(x => x.Attributes["GIC4.DBO.PROJECT_INFO.PROJ_NAME"]).ToList(); featureSet.Features.Clear(); foreach (var g11 in gsort) { featureSet.Features.Add(g11); } GraphicsLayer gl = MyMap.Layers["glayer"] as GraphicsLayer; foreach (Graphic graphic in args.FeatureSet.Features) { g = new Graphic(); g.Symbol = LayoutRoot.Resources["DefaultpointSymbol"] as SimpleMarkerSymbol; FeatureLayer fl = MyMap.Layers["polygonlayer"] as FeatureLayer; string a = graphic.Attributes["GIC4.DBO.PROJECT_LOCATION_POLY.LOCATION_ID"].ToString(); int k = featureSet.Features.Count(gtt => gtt.Attributes["GIC4.DBO.PROJECT_LOCATION_POLY.LOCATION_ID"] != null && (int)gtt.Attributes["GIC4.DBO.PROJECT_LOCATION_POLY.LOCATION_ID"] == int.Parse(graphic.Attributes["GIC4.DBO.PROJECT_LOCATION_POLY.LOCATION_ID"].ToString())); k = featureSet.Features.Count(gtt => gtt.Attributes["GIC4.dbo.RFP.Project_Id"] != null && (int)gtt.Attributes["GIC4.dbo.RFP.Project_Id"] == 291); g = fl.Graphics.FirstOrDefault(gtt => gtt.Attributes["LOCATION_ID"] != null && (int)gtt.Attributes["LOCATION_ID"] == int.Parse(graphic.Attributes["GIC4.DBO.PROJECT_LOCATION_POLY.LOCATION_ID"].ToString())); ggl = new Graphic(); if (g != null) { ggl.Geometry = g.Geometry; if(k >1) ggl.Attributes.Add("PROJSTAT", "M"); else ggl.Attributes.Add("PROJSTAT", graphic.Attributes["GIC4.DBO.PROJECT_INFO.PROJSTAT"].ToString()); gl.Graphics.Add(ggl); } } } else MessageBox.Show("No features returned from query"); } Please help me,even on featurelayer_initialized i am getting 0 count. where i am writing wrong? Please help, Foram

DominiqueBroux · Answer

I put break point also but eveytime it says 0 count on feature layer.and on button click its working fine and it gives me perfect count

That seems to mean that your code 'getprojects.projectsClient obj = new getprojects.projectsClient();' needs a specific state to work.

I have no idea about your code, but if it needs another feature layer to be initialized --> call it on event Layer_Intialized.
but I am using multiple tables and i can't use join because it is having one to many relationship.so i am not sure how i can implement unique value renderer?

Your code :if (e.Result.PROJSTAT.ToString() == "F" || e.Result.PROJSTAT.ToString() == "P")
ggl.Symbol = LayoutRoot.Resources["DefaultpointSymbol"] as SimpleMarkerSymbol;
else
ggl.Symbol = LayoutRoot.Resources["esriDefaultMarker_40"] as MarkerSymbol;

seems to define the symbol from a simple attribute value.
Nothing prevent you to add this attribute to your graphic :
g.Attributes["PROJSTAT"] = e.Result.PROJSTAT.ToString();

That being said, it's not a major point. Just my 2cts.