topic Re: Zoom to multiple Feature Layers in ArcGIS API for Silverlight Questions

Zoom to multiple Feature Layers

SantoshV — Tue, 21 Feb 2012 03:15:58 GMT

Hi, I have a query where I add many feature in runtime..
now i write

               
 if (projFeatureLayer.FullExtent != null)
                {
                    double projectXMin = projFeatureLayer.FullExtent.XMin;
                    double projectXMax = projFeatureLayer.FullExtent.XMax;
                    double projectYMin = projFeatureLayer.FullExtent.YMin;
                    double projectYMax = projFeatureLayer.FullExtent.YMax;
                    //To also Envelope a single point
                    double coordOffset = .01;

                    if (projectXMin == projectXMax && projectYMin == projectYMax)
                    {
                        projectXMax = projectXMax + coordOffset;
                        projectXMin = projectXMin - coordOffset;
                    }

                    //Set Zoom Duration (Time)
                    mainPage.map.ZoomDuration = new TimeSpan(0, 0, Convert.ToInt32(App.Current.Resources["ZoomDuration"]));

                    Envelope projectEnvelope = new Envelope(projectXMin, projectYMin, projectXMax, projectYMax);
                    //Set zoom Extents
                    mainPage.map.ZoomTo(projectEnvelope.Expand(Convert.ToDouble(App.Current.Resources["ZoomExpand"])));
                    mainPage.panelCustomLegend.Visibility = System.Windows.Visibility.Visible;

                    //mainPage.boolRefreshCustomLegend = true;
                    //mainPage.CustomLegend.Refresh();

                    return true;
                }

to zoom to one feature layer on "feature layer update-completed event" but how do I zoom to all the feature layers added on the map...??

Please guide

Re: Zoom to multiple Feature Layers

OrlandoCarvajal — Tue, 21 Feb 2012 14:33:11 GMT

If you are loading multiple layers at runtime at once and you want to do some processing after all of them have finished updating, you'll have to keep a counter to find out when all of them have completed. Then you can calculate the extent from all layers by using Union() and do your zoom ...
I hope that's what you are looking for; I'm not quite sure of your scenario.

Re: Zoom to multiple Feature Layers

SantoshV — Wed, 22 Feb 2012 05:42:08 GMT

If you are loading multiple layers at runtime at once and you want to do some processing after all of them have finished updating, you'll have to keep a counter to find out when all of them have completed. Then you can calculate the extent from all layers by using Union() and do your zoom ...
I hope that's what you are looking for; I'm not quite sure of your scenario.

[ATTACH=CONFIG]12111[/ATTACH]

Hi thanks you for your reply..
I am sorry I did not give enough information about the query..

I have a query where the input values need me to query upto 3 ranges and I return 3 thematics with different symbology on the map
therefore I have created 3 layers with different symbology but same data and created a service to access it..

here I am adding 3 feature layers onto the map .Since the query keysin values in range, for everyvalue keydin I create a new feature layer and display it on the map
1 feature layer for every range. so after adding 3 different feature layers I would like to zoom to its extent.
therefore I need to either merge(ie union the feature layer) else add up the extents..
is it possible to add the extents so that I can fix all the 3 feature layer on the map..
Please guide...

Re: Zoom to multiple Feature Layers

OrlandoCarvajal — Sat, 11 Dec 2021 15:57:40 GMT

That's what I meant by Union(). See example:

                Envelope extent = new Envelope();
                foreach (FeatureLayer featureLayer in featureLayers)
                    foreach (Graphic graphic in featureLayer.Graphics)
                        if (graphic.Geometry != null)
                            extent = extent.Union(graphic.Geometry.Extent);

                // do zoom ...

Re: Zoom to multiple Feature Layers

SantoshV — Thu, 23 Feb 2012 03:38:39 GMT

Thnx for your reply

I saved the XMin, XMax, YMin, YMax from the feature layer calculated the envelope and zoomed to it , it worked fine anywys 🙂