Latest Contributions by AndrewBiggins

The new LayerList widget is great, but currently it only supports Feature Layers and map services. It would be much more useful if it also supported graphics layers. A 'remove layer' button built into the widget would be also be a useful option. ... View more

I have tried the GeometryEngine.union method (within JavaScript 3.15 API) but it throws the following error when it is placed within a try-catch statement: TypeError: Unable to get property 'hq' of undefined or null reference It seems to work when not placed within a try-catch, but since it is throwing this error I'm concerned about using it within a production application. Also, the equivalent Union method in the ArcGIS Server GeometryService does not throw an error. I thought the error might be due to undefined spatial references in the array of geometries passed to it, but I have checked and they are all defined. Can anyone please advise why this error is being thrown? arrayUtils.forEach(AdviceGlobal.savedFeaturesGraphicsLayer.graphics, function (savedGraphic) { // Define spatial reference for geometryEngine var thisGeometry = savedGraphic.geometry; console.log(thisGeometry.spatialReference); if (thisGeometry.spatialReference == null) {   thisGeometry.spatialReference = map.spatialReference; } geometryToCapture.push(thisGeometry); }); // Try geometryEngine try {     var unionedGeometry = geometryEngine.union(geometryToCapture);     saveFeature(unionedGeometry); } catch (e) {     onUnionError(e); } ... View more

Hello, I am having a problem with using the IdentifyTask in conjunction with a QueryTask and the MaxAllowableOffset option. I am first using the IdentifyTask to find features in a dynamic map service layer that intersect a given graphics layer feature. Then if any of the features have more than a certain number of vertices I am running a QueryTask and setting MaxAllowableOffset to generalise the feature, but only for those features. This works fine the first time it is run, but after the first run the IdentifyTask appears to be using the MaxAllowableOffset value that was set by the QueryTask, so all the features are generalised by the IdentifyTask! I have tried setting MaxAllowableOffset for the IdentifyTask to zero (via IdentifyParameters.MaxAllowableOffset) and this didn't fix the problem. However, when I set IdentifyParameters.MaxAllowableOffset to a small value (0.001 metres) it fixed the problem. This doesn't seem like a nice workaround, so I'm hoping someone can explain why this is happening, or whether this is a bug? Cheers, Andrew Here's a summary of the code: IdentifyParameters sitesQueryIdentifyParams = new IdentifyParameters(); sitesQueryIdentifyParams.Geometry = selectedUnionedGeometry; sitesQueryIdentifyParams.MapExtent = _map.Extent; sitesQueryIdentifyParams.Width = (int)_map.ActualWidth; sitesQueryIdentifyParams.Height = (int)_map.ActualHeight; // Set sites query identify tolerance to 0 pixels sitesQueryIdentifyParams.Tolerance = 0; sitesQueryIdentifyParams.LayerOption = LayerOption.all; // Perform identify on Sites layer sitesQueryIdentifyParams.LayerIds.Add(Convert.ToInt16(_sitesLayerId)); sitesQueryIdentifyParams.SpatialReference = _map.SpatialReference; // TEST - Explicitly set MaxAllowableOffset - this only works when set to a small value sitesQueryIdentifyParams.MaxAllowableOffset = 0.001; // Perform Sites Query Identify operation (asynchronously) IdentifyTask sitesQueryIdentifyTask = new IdentifyTask(_ahelpPilotMapUrl); // Disable caching identify results sitesQueryIdentifyTask.DisableClientCaching = true; sitesQueryIdentifyTask.ExecuteCompleted += SitesQueryIdentifyTask_ExecuteCompleted; sitesQueryIdentifyTask.Failed += SitesQueryIdentifyTask_Failed; sitesQueryIdentifyTask.ExecuteAsync(sitesQueryIdentifyParams, graphicsLayerLabel); ... private void SitesQueryIdentifyTask_ExecuteCompleted(object sender, IdentifyEventArgs args) { _identifyGraphics = new List<Graphic>(); foreach (IdentifyResult result in args.IdentifyResults) {   _identifyGraphics.Add(result.Feature); } // Loop through graphics, for each graphic count number of vertices (polygons/lines only) and if greater than a threshold generalise _identifyGraphicsToGeneralise = new List<Graphic>(); _identifyGeneraliseCompleteCount = 0; foreach (Graphic identifyGraphic in _identifyGraphics) {   int identifyVerticeCount = 0;   if (identifyGraphic.Geometry is ESRI.ArcGIS.Client.Geometry.Polygon)   {    ESRI.ArcGIS.Client.Geometry.Polygon identifyPolygon = (ESRI.ArcGIS.Client.Geometry.Polygon)identifyGraphic.Geometry;    ObservableCollection<ESRI.ArcGIS.Client.Geometry.PointCollection> identifyPolyRings = identifyPolygon.Rings;    foreach (ESRI.ArcGIS.Client.Geometry.PointCollection identifyRing in identifyPolyRings)    {     identifyVerticeCount += identifyRing.Count;    }   }   else if (identifyGraphic.Geometry is ESRI.ArcGIS.Client.Geometry.Polyline)   {    ESRI.ArcGIS.Client.Geometry.Polyline identifyPolyline = (ESRI.ArcGIS.Client.Geometry.Polyline)identifyGraphic.Geometry;    foreach (ESRI.ArcGIS.Client.Geometry.PointCollection identifyPath in identifyPolyline.Paths)    {     identifyVerticeCount += identifyPath.Count;    }   }   if (identifyVerticeCount > _MAX_VERTICES)   {    // Add to list of graphics to generalise    _identifyGraphicsToGeneralise.Add(identifyGraphic);   } } foreach (Graphic identifyGeneraliseGraphic in _identifyGraphicsToGeneralise) {   // Use QueryTask to run query for this graphic, set MaxAllowableOffset to reduce vertices   QueryTask identifyQueryGeneralizeTask = new QueryTask(_ahelpPilotMapUrl + "/" + _sitesLayerId);   // Disable caching query results   identifyQueryGeneralizeTask.DisableClientCaching = true;   identifyQueryGeneralizeTask.ExecuteCompleted += IdentifyQueryTaskGeneralize_ExecuteCompleted;   identifyQueryGeneralizeTask.Failed += IdentifyQueryTaskGeneralize_Failed;   ESRI.ArcGIS.Client.Tasks.Query identifyQueryGeneralize = new ESRI.ArcGIS.Client.Tasks.Query();   // Set up query for given feature   identifyQueryGeneralize.Where = _OBJECTID_FIELD_NAME + "=" + identifyGeneraliseGraphic.Attributes[_OBJECTID_FIELD_NAME].ToString();   // Specify same projection as first layer of map, as this will determine overall spatial projection   identifyQueryGeneralize.OutSpatialReference = _map.SpatialReference;   identifyQueryGeneralize.ReturnGeometry = true;   // Set max allowable offset for sites with a lot of vertices, to reduce size of geometry returned   identifyQueryGeneralize.MaxAllowableOffset = _MAX_ALLOWABLE_OFFSET;   // Add all fields to query so they are all returned with geometry   identifyQueryGeneralize.OutFields.Add("*");   identifyQueryGeneralizeTask.ExecuteAsync(identifyQueryGeneralize, identifyGeneraliseGraphic); } ... ... 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Hi, I am using a geometry service's ProjectAsync method to project some graphics in an application, and I am passing the graphic layer name as a string using the userToken parameter: GeometryService ProjectShapefileService = new GeometryService(_geometryServiceUrl); ProjectShapefileService.ProjectCompleted += ProjectShapefileService_ProjectCompleted; ProjectShapefileService.Failed += ProjectShapefileService_Failed; ProjectShapefileService.ProjectAsync(thisShapefileGraphics, _map.SpatialReference, shapefileName); This works fine, except that when the project operation fails the UserState object that is returned via the Failed event (within the args object) does not match the type of the userToken parameter (in this case it is not a string). Instead it is a generic object array (see attached screenshot for debugging example). private void ProjectShapefileService_Failed(object sender, TaskFailedEventArgs args) { // This is what I need to do to get to the graphics layer name (passed via the userToken parameter) object[] thisUserState = (args.UserState as object[])[0] as object[]; string thisShapefileName = thisUserState[2] as string; // If this worked like other geometry service methods, I should be able to do this instead. Why not? //string thisShapefileName = args.UserState as string; Is there an easier way to get to the userToken parameter that was passed to the geometry service? Cheers, Andrew ... View more

Hi, I am using the legend control and have set up a MapLayerTemplate, LayerTemplate and LegendItemTemplate to control how the legend items are drawn. This is working fine, but now I am trying to create a different template for graphics layers in the map, so I can add a right-click context menu that appears only when clicking on graphics layers. I can see three approaches to this, but I can't see how to get any of them to work: 1. Set up multiple templates in XAML (It looks as if this will be supported in Silverlight 5, but can this be done somehow at version 4?). 2. Change the data template in code behind. 3. Bind data template elements in XAML and use a valueconverter to set visibility property. I can't see how to do the first two approaches, but I have found some silverlight examples that try the third approach (e.g. http://forums.silverlight.net/t/215879.aspx), so I have tried this in the code below. Unfortunately it doesn't work and the valueconverter code doesn't get called at all. XAML code: <UserControl.Resources>     <ahelp:ContextMenuVisibilityConverter x:Key="VisibilityConverter" /> </UserControl.Resources> ... <esri:Legend.MapLayerTemplate> <DataTemplate>   <Grid Width="210" Height="Auto" >    <Grid.ColumnDefinitions>     <ColumnDefinition Width="Auto" />     <ColumnDefinition />    </Grid.ColumnDefinitions>    <CheckBox Content="{Binding Label}"        IsChecked="{Binding IsEnabled, Mode=TwoWay}"        IsEnabled="True" HorizontalAlignment="Left" Grid.Column="0" >    </CheckBox>    <Slider Maximum="1" Value="{Binding Layer.Opacity,Mode=TwoWay}" Width="60" Margin="5,0,0,0" HorizontalAlignment="Right" Grid.Column="1" ></Slider>    <toolkit:ContextMenuService.ContextMenu>     <toolkit:ContextMenu Name="LayerContextMenu">      <toolkit:MenuItem Name="ZoomToLayerContextMenuItem" Header="Zoom to Layer" Visibility="{Binding Name, Converter={StaticResource VisibilityConverter}, ConverterParameter=Name}">       <toolkit:MenuItem.Icon>        <Image Source="UserControls/Images/ZoomInSmall.png" Stretch="None"  Margin="0" />       </toolkit:MenuItem.Icon>      </toolkit:MenuItem>      <toolkit:Separator Name="SeparatorContextMenuItem" />      <toolkit:MenuItem Name="RemoveLayerContextMenuItem" Header="Remove Layer">       <toolkit:MenuItem.Icon>        <Image Source="UserControls/Images/RemoveLayerSmall.png" Stretch="None" Margin="0" />       </toolkit:MenuItem.Icon>      </toolkit:MenuItem>     </toolkit:ContextMenu>    </toolkit:ContextMenuService.ContextMenu>   </Grid> </DataTemplate> </esri:Legend.MapLayerTemplate> C# code behind: public class ContextMenuVisibilityConverter : IValueConverter { public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) {   string valueString = value as string;   if (valueString.Contains("GraphicsLayer"))    return Visibility.Visible;   else    return Visibility.Collapsed; } public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture) {   throw new NotImplementedException(); } } In the XAML code, can the following line be changed so the valueconverter is called and the name of the layer is passed? Visibility="{Binding Name, Converter={StaticResource VisibilityConverter}, ConverterParameter=Name}" Any help would be much appreciated! Cheers, Andrew ... View more