topic Re: Identify Task issues in ArcGIS API for Silverlight Questions

Identify Task issues

AngelGonzalez — Tue, 13 Apr 2010 15:40:48 GMT

I am using the ESRI sample for Identify and got a problem. I have a sublayer list with about 13 layers. Only the first 4 are set to be visible when the silverlight app is first run. The identify Task works fine with these first 4 layers. When I click on the checkbox to make another layer visible and use the Identify tool the fifth layer does not appear on the identify tool. Yet when I go back and update the mxd to make the fifth layer visible and reboot my ArcGIS server (the refreshing of a service to pickup and any changes made to the mxd is not being pickup by Silverlight app, only a reboot will do this , bug??) the identify tool picks up the the fifth layer.

Does the Identify task works with sublayer list? Do I need to refresh something?
I am using SL3 with ESRI 1.2 SL API

Thanks

Angel

Identify Task issues

dotMorten_esri — Tue, 13 Apr 2010 16:29:10 GMT

Did you set the LayerIds property on the identify parameters to match the visible layers of the map?

Identify Task issues

AngelGonzalez — Tue, 13 Apr 2010 22:38:17 GMT

Yes, I found the following thread:

http://forums.esri.com/Thread.asp?c=158&f=2455&t=298582&mc=11

and it gave me some clues. Debugging in VS and with Fiddler I see the Layerid being sent across but it is not returning anything for this layer. If I turn off a layer that was originally set to be visible and do an identify it does not show up(which is correct). If I turn on this same layer again it does. The only issues are with layers whose visibility are set to false at startup. Any clues?

Thanks

Angel

Re: Identify Task issues

ERNESTOGIRON — Fri, 30 Jul 2010 18:10:33 GMT

angelg:

As shapGIS said you have to set the LayersIds property, but don't set LayerOption at the same time. Use LayerOption property (All, Top, Visible) if you start up your service with any layer visible.

Try to use for example LayerIds = [0,1,2,etc] . It works for me using 110 layers off at startup.

I hope it helps.

Re: Identify Task issues

DavidAshton — Mon, 04 Oct 2010 17:52:24 GMT

Hello egrion or angelg,

I am trying to follow your guys trail of post to solve the same problem that angelg was looking to solve. I was hoping to link up my sublayer list with the identify tool so the identify tool only works with the layers that are checked visible. Currently I have over 50 layers and it takes a while to identify because it is identifing all 50 and I only want to identify the one visible. I'm having trouble. Would/Could you post your code to get these two tools to work together?

Thanks
Dave

Re: Identify Task issues

DavidAshton — Sat, 11 Dec 2021 23:31:34 GMT

angelg:

As shapGIS said you have to set the LayersIds property, but don't set LayerOption at the same time. Use LayerOption property (All, Top, Visible) if you start up your service with any layer visible.

Try to use for example LayerIds = [0,1,2,etc] . It works for me using 110 layers off at startup.

I hope it helps.

Ernesto,

If I change the LayerOption = LayerOption.all the identify tool will identify all my layers no matter what is checked in my sublayer list. If I change LayerOption = LayerOption.visible the identify tool doesn't respect the layerlist.....it only identifies the layers that were visible at startup.

Where do I hard code the layers (like you stated) LayerIds = [0,1,2,etc] I can't find this code and I'm unsure where to add it?

Or better yet how do I make the identify pick up the new visible layers from the sublayer list?

Thanks
D


  #region Identify
        // Jay's Identify

        private void QueryPoint_MouseClick(object sender, System.Windows.Input.MouseButtonEventArgs e)
        {
            e.Handled = true; // to get rid of the default "Silverlight" Context Menu.
            ESRI.ArcGIS.Client.Geometry.MapPoint clickPoint = this.Map.ScreenToMap(e.GetPosition(Map));


            ESRI.ArcGIS.Client.Tasks.IdentifyParameters identifyParams = new IdentifyParameters()
            {
                Geometry = clickPoint,
                MapExtent = Map.Extent,
                Width = (int)Map.ActualWidth,
                Height = (int)Map.ActualHeight,
                LayerOption = LayerOption.all
            };

            IdentifyTask identifyTask = new IdentifyTask("http://hqtr-gis10/ArcGIS/rest/services/DRECP_20101008/MapServer");
            identifyTask.ExecuteCompleted += IdentifyTask_ExecuteCompleted;
            identifyTask.Failed += IdentifyTask_Failed;
            identifyTask.ExecuteAsync(identifyParams);

            GraphicsLayer graphicsLayer = Map.Layers["MySelectionGraphicsLayer"] as GraphicsLayer;
            graphicsLayer.ClearGraphics();
            ESRI.ArcGIS.Client.Graphic graphic = new ESRI.ArcGIS.Client.Graphic()
            {
                Geometry = clickPoint,
                Symbol = LayoutRoot.Resources["DefaultPictureSymbol"] as ESRI.ArcGIS.Client.Symbols.Symbol
            };
            graphicsLayer.Graphics.Add(graphic);
        }

        public void ShowFeatures(List<IdentifyResult> results)
        {
            _dataItems = new List<DataItem>();

            if (results != null && results.Count > 0)
            {
                IdentifyComboBox.Items.Clear();
                foreach (IdentifyResult result in results)
                {
                    Graphic feature = result.Feature;
                    string title = result.Value.ToString() + " (" + result.LayerName + ")";
                    _dataItems.Add(new DataItem()
                    {
                        Title = title,
                        Data = feature.Attributes
                    });
                    IdentifyComboBox.Items.Add(title);
                }
                IdentifyComboBox.SelectedIndex = 0;
            }
        }

        void cb_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            int index = IdentifyComboBox.SelectedIndex;
            if (index > -1)
                IdentifyDetailsDataGrid.ItemsSource = _dataItems[index].Data;
        }

        private void IdentifyTask_ExecuteCompleted(object sender, IdentifyEventArgs args)
        {
            IdentifyDetailsDataGrid.ItemsSource = null;

            if (args.IdentifyResults != null && args.IdentifyResults.Count > 0)
            {
                IdentifyResultsPanel.Visibility = Visibility.Visible;

                ShowFeatures(args.IdentifyResults);
                ShowIDtab.Begin();
            }
            else
            {
                IdentifyComboBox.Items.Clear();
                IdentifyComboBox.UpdateLayout();

                IdentifyResultsPanel.Visibility = Visibility.Collapsed;
                
            }
        }

        public class DataItem
        {
            public string Title { get; set; }
            public IDictionary<string, object> Data { get; set; }
        }

        void IdentifyTask_Failed(object sender, TaskFailedEventArgs e)
        {
            MessageBox.Show("Identify failed. Error: " + e.Error);
        }


        //end Jay's identify
        #endregion

Re: Identify Task issues

MarkCederholm — Mon, 11 Oct 2010 16:04:26 GMT

I'm trying to set the LayerIDs property and Visual Studio says it's read-only. Is that a bug?

Re: Identify Task issues

dotMorten_esri — Mon, 11 Oct 2010 18:23:00 GMT

The property is read only, but the collection is not.
Ie: identifyParams.LayerIDs.Add(1);

Re: Identify Task issues

MarkCederholm — Mon, 11 Oct 2010 18:27:56 GMT

That did the trick. Thanks!

Re: Identify Task issues

DavidAshton — Sat, 11 Dec 2021 23:31:36 GMT

With the help of Morton answering Mark question I was able to somewhat answer mine. Now I�??m hoping maybe Mark, Morton, Ernesto or some other kind sole will be able to help me Solve the final parts of my problem.

I took what Morton told Mark and add this to my code, it seems like it now only identifies the layers 1,5,14,17, and 18. But it doesn�??t respect the fact if they are visible. If I set LayerOption = LayerOption.visible it only works for the layers visible at start up and doesn't respect the identifyParams.LayerIds.Add statements.

Two questions:
Is there a way to have the identify tool respect the sublayer list visible layers?

Like Ernesto pointed out how do I just write identifyParams.LayerIds.Add(1,5,17,18) or identifyParams.LayerIds.Add[1,5,17,18], both give errors in VS; I don�??t want to keep listing identifyParams.LayerIds.Add() over and over.


ESRI.ArcGIS.Client.Tasks.IdentifyParameters identifyParams = new IdentifyParameters

            
            {
                
                Geometry = clickPoint,
                MapExtent = Map.Extent,
                Width = (int)Map.ActualWidth,
                Height = (int)Map.ActualHeight,
                LayerOption = LayerOption.all,
            
                

            };
            //these identifyParams.LayerIds.Add do nothing if LayerOption is set to visible
           //these identifyParams.LayerIds.Add work if LayerOption is set to all but doesn't respect if the layers are turned on/off

            identifyParams.LayerIds.Add(1);
            identifyParams.LayerIds.Add(5);
            identifyParams.LayerIds.Add(14);
            identifyParams.LayerIds.Add(17);
            identifyParams.LayerIds.Add(18);


            // identifyParams.LayerIds = [2, 5];  This errors out not sure how to list a list

Re: Identify Task issues

JenniferNery — Tue, 12 Oct 2010 17:18:08 GMT

For your first question:
identifyParams.LayerOption = LayerOption.visible;
For your second question:
identifyParams.LayerIds.AddRange(new int[] {1,5,17,18});

Re: Identify Task issues

MarkCederholm — Tue, 12 Oct 2010 17:32:11 GMT

The only method I've found is to keep track of which layers are visible at a given "scale" (ESRI deprecates that term nowadays) and provide those IDs with the "all" option each time I make an identify request. It takes a bit of logic to sort through the layers, I'm afraid.

Check out the table of contents at the silverlight code gallery for an example of maintaining visibility info. You can use REST calls to grab the min and max scales for each layer, but that's pretty chatty. To keep things simpler, what I ended up doing was create a WCF service to get all the layer info with one SOAP call: if you add a web reference to the map service in your ASP project it automatically builds the methods and data structures for you.

Re: Identify Task issues

SanjayRajput — Mon, 01 Nov 2010 19:28:42 GMT

Hello Mark Cederholm/Others
I am looking for the code snippet to find the current visible layers of a given dynamicmapservice.
During application startup, dynamicmapservice loads all visible layers on the map(defined in the mxd). But after a while users can TURNON/TURNOFF layers. And when I do the QUERYTASK, I should be able to QUERY only current visible layers.
Thanks
Sanjay

The only method I've found is to keep track of which layers are visible at a given "scale" (ESRI deprecates that term nowadays) and provide those IDs with the "all" option each time I make an identify request. It takes a bit of logic to sort through the layers, I'm afraid.

Check out the table of contents at the silverlight code gallery for an example of maintaining visibility info. You can use REST calls to grab the min and max scales for each layer, but that's pretty chatty. To keep things simpler, what I ended up doing was create a WCF service to get all the layer info with one SOAP call: if you add a web reference to the map service in your ASP project it automatically builds the methods and data structures for you.

Re: Identify Task issues

MarkCederholm — Mon, 01 Nov 2010 19:48:24 GMT

Again, I highly recommend the Silverlight Table of Contents code example in the code gallery. Here's a link to it:

http://www.arcgis.com/home/item.html?id=acad4f3fb7d04854ab8dbe3fc5f79fc5

Re: Identify Task issues

MatthewPilgrim — Tue, 30 Nov 2010 09:21:39 GMT

Hi,

I have a similar issue to the first poster (my last layer fails) however my layer is on by default and I get this exception from ESRI.ArcGIS.Client.Tasks.TaskFailedEventArgs:

Error {System.Net.WebException: The remote server returned an error: NotFound. ---> System.Net.WebException: The remote server returned an error: NotFound.
   at System.Net.Browser.BrowserHttpWebRequest.InternalEndGetResponse(IAsyncResult asyncResult)
   at System.Net.Browser.BrowserHttpWebRequest.<>c__DisplayClass5.<EndGetResponse>b__4(Object sendState)
   at System.Net.Browser.AsyncHelper.<>c__DisplayClass2.<BeginOnUI>b__0(Object sendState)
   --- End of inner exception stack trace ---
   at System.Net.Browser.AsyncHelper.BeginOnUI(SendOrPostCallback beginMethod, Object state)
   at System.Net.Browser.BrowserHttpWebRequest.EndGetResponse(IAsyncResult asyncResult)
   at System.Net.WebClient.GetWebResponse(WebRequest request, IAsyncResult result)
   at System.Net.WebClient.DownloadBitsResponseCallback(IAsyncResult result)} System.Exception {System.Net.WebException}

My service has layer ids 0,2,3,4,5,6 (note no number one - and none of them are group layers). All work except 6. I have tried calling the Identify task with and without layer options but I still get the exception.

If I pass in Id "5" the results come back for a layer with the correct name - excellent.
If I pass in Id "1" I don't get an exception, but I also get no results.
If I pass in Id "7" I get the same exception as before.

Any Ideas?

Thanks, Matt

Re: Identify Task issues

JenniferNery — Sat, 11 Dec 2021 23:31:39 GMT

Subscribe to Failed event and check for exception. Also, you might want to run Fiddler with your application to see more information on which web request failed.

 
void QueryTask_Failed(object sender, TaskFailedEventArgs e)
{
 if (e.Error is ServiceException)
 {
  StringBuilder sb = new StringBuilder();
  foreach(string detail in (e.Error as ServiceException).Details)
   sb.Append(string.Format("{0}\n", detail));
  MessageBox.Show(string.Format("Error: {0}", sb.ToString()));
 }
}

If the layer ID is up to 6, ID=7 is expected to fail, right?

Try to see if putting the same parameters from the web browser will result to the same error.

Re: Identify Task issues

MatthewPilgrim — Tue, 30 Nov 2010 18:27:57 GMT

Jennifer thanks for your response.

Yes I expect 7 to fail.

The exception is of type "System.Net.WebException" so I don't think your code snippet helps.

I'm looking into fiddler and calling the service, not something I've done before.

Matt

Re: Identify Task issues

JenniferNery — Tue, 30 Nov 2010 18:37:19 GMT

You can place a breakpoint in the Failed event handler, if it does go there.

Post #14 in this thread might guide you in finding what you need to look for in Fiddler: http://forums.arcgis.com/threads/14730-Area-And-Perimeter

Re: Identify Task issues

MatthewPilgrim — Tue, 30 Nov 2010 18:47:23 GMT

Hi,

the exception I posted orginally was fromn the failed event handler and is as much information as I can see at that point.

From fiddler I can see the server response is:

Server Error - Index was outside the bounds of the array

This is the service:

This is me calling it (note the watch value is 6):

I'm trying to callit direct at the moment.

Matt

Re: Identify Task issues

MatthewPilgrim — Tue, 30 Nov 2010 18:59:21 GMT

from fiddler:

tolerance 2
returnGeometry true
mapExtent 3219613.08846863,1726402.76275839,3226995.61041765,1732899.38207353
layers top:6
imageDisplay 1175,825,96
geometryType esriGeometryPolygon
geometry {"spatialReference":{"wkid":2232},"rings":[[[3219613.08846863,1732899.38207353],[3226995.61041765,1732899.38207353],[3226995.61041765,1726402.76275839],[3219613.08846863,1726402.76275839],[3219613.08846863,1732899.38207353]]]}
f json

One thing I notice is that it says "top:6", I didn't specify Top.

I have now tested the webservice direct with All:6 and Top:6 and in both cases get:

Server Error - Index was outside the bounds of the array.

Code: 500

Is it really using Ids and not Index or is it doing a bit of both????

Matt