topic Re: Zoom to Feature_layer not working when count is 1 in ArcGIS API for Silverlight Questions

Zoom to Feature_layer not working when count is 1

SantoshV — Tue, 10 Jan 2012 07:40:29 GMT

HI,
I have a method which returns a feature layer and zooms to it on the map..
but when the feature layer count is 1 the map does not zoom to the feature....

 //zoom to featurelayer
        void featureLayer_UpdateCompleted(object sender, EventArgs e)
        {
            FeatureLayer projFeatureLayer = (FeatureLayer)sender;
            SetLegend();
            if (projFeatureLayer.FullExtent != null)
            {
                double projectXMin = projFeatureLayer.FullExtent.XMin;
                double projectXMax = projFeatureLayer.FullExtent.XMax;
                double projectYMin = projFeatureLayer.FullExtent.YMin;
                double projectYMax = projFeatureLayer.FullExtent.YMax;
                double coordOffset = .01;

                //Envelope cannot be a single point?
                if (projectXMin == projectXMax && projectYMin == projectYMax)
                {
                    projectXMax = projectXMax + coordOffset;
                    projectXMin = projectXMin - coordOffset;
                }

                Envelope projectEnvelope = new Envelope(projectXMin, projectYMin, projectXMax, projectYMax);
                mainPage.map.ZoomTo(projectEnvelope);
            }
            else
            { 
                mainPage.lblcustomStatusBar.Content = "Feature not found";
                mainPage.lblcustomStatusBar.Foreground = new SolidColorBrush(Colors.Red);
                mainPage.panelCustomLegend.Visibility = System.Windows.Visibility.Collapsed;
            }
        }

Please do guide...

Re: Zoom to Feature_layer not working when count is 1

JMcNeil — Tue, 10 Jan 2012 21:39:25 GMT

Are you working with points?

Re: Zoom to Feature_layer not working when count is 1

SantoshV — Wed, 11 Jan 2012 04:50:11 GMT

Are you working with points?

Thnk you for the reply..
Yes I am working with point features here...

Re: Zoom to Feature_layer not working when count is 1

DominiqueBroux — Wed, 11 Jan 2012 11:27:05 GMT

I tested your code with the FeatureLayerSimple interactive sample and it looks working (despite there is only one feature layer).

Could you give more info on how to reproduce the issue? Thanks

Re: Zoom to Feature_layer not working when count is 1

SantoshV — Sat, 11 Dec 2021 20:51:46 GMT

I tested your code with the FeatureLayerSimple interactive sample and it looks working (despite there is only one feature layer).

Could you give more info on how to reproduce the issue? Thanks

The code does work with a feature layer when the count is greater than 1 what I am talking is when the feature layer count is 1..
i.e only one feature....

for example in a graphics layer also when the graphic count is 1 the graphicsLayer.FullExtent.Width and graphicsLayer.FullExtent.Height is 0.0 but when the graphics count is greater than 2 it has values

FeatureSet featureSet = e.FeatureSet;
                if (featureSet != null && featureSet.Features.Count > 0)
                {
                    // If an item has been selected            
                    GraphicsLayer graphicsLayer = mainPage.map.Layers["tempGraphicLayer"] as GraphicsLayer;
                    if (graphicsLayer == null)
                    {
                        graphicsLayer = new GraphicsLayer();
                        graphicsLayer.ID = "tempGraphicLayer";
                        mainPage.map.Layers.Add(graphicsLayer);
                    }

                    Graphic selectedFeature = null;
                    for (int i = 0; i < featureSet.Features.Count; i++)
                    {
                        // Show selected feature attributes in DataGrid
                        selectedFeature = featureSet.Features;
                        selectedFeature.Symbol = LayoutRoot.Resources["MarkerSymbol"] as ESRI.ArcGIS.Client.Symbols.Symbol;
                        graphicsLayer.Graphics.Add(selectedFeature);
                    }
                    graphicsLayer.Opacity = 0.7;
                    double expandPercentage = 30;
                    double widthExpand = graphicsLayer.FullExtent.Width * (expandPercentage / 100);
                    double heightExpand = graphicsLayer.FullExtent.Height * (expandPercentage / 100);
                    if (graphicsLayer != null)
                    {

                        ESRI.ArcGIS.Client.Geometry.Envelope displayExtent = new ESRI.ArcGIS.Client.Geometry.Envelope(
                        graphicsLayer.FullExtent.XMin - (widthExpand / 2),
                        graphicsLayer.FullExtent.YMin - (heightExpand / 2),
                        graphicsLayer.FullExtent.XMax + (widthExpand / 2),
                        graphicsLayer.FullExtent.YMax + (heightExpand / 2));
                        mainPage.map.ZoomTo(displayExtent);

                        KeyValuePair<int, string> str = (KeyValuePair<int, string>)lstChainage.SelectedItem;
                        mainPage.lblcustomStatusBar.Content = str.Value + " located";
                        mainPage.lblcustomStatusBar.Foreground = new SolidColorBrush(Colors.Blue);
                    }
                }

Re: Zoom to Feature_layer not working when count is 1

DominiqueBroux — Thu, 12 Jan 2012 05:47:53 GMT

I tweaked the FeatureLayerSimple sample to return only one feature (Where="CITY_NAME='Spokane'") and your initial code is still working.

Though the code you just posted is not working since the FullExtent size is zero (the size of one point geometry is zero : that's normal).
So I suggest that in this case you introduce a minimum size (as you did in your first post with 'coordOffset')

Re: Zoom to Feature_layer not working when count is 1

SantoshV — Thu, 12 Jan 2012 08:52:14 GMT

I tweaked the FeatureLayerSimple sample to return only one feature (Where="CITY_NAME='Spokane'") and your initial code is still working.

Though the code you just posted is not working since the FullExtent size is zero (the size of one point geometry is zero : that's normal).
So I suggest that in this case you introduce a minimum size (as you did in your first post with 'coordOffset')

Yup your right I changed the value to 0.01 and it worked fine..
thnx a bunch 🙂