topic Re: identifyLayersWithMaxResults crashes app in ArcGIS AppStudio Questions

identifyLayersWithMaxResults crashes app

KyleSchultz1 — Sun, 12 Dec 2021 16:57:40 GMT

I have a map with multiple feature layers.

I'm trying to identify a layer that is clicked on but I do not know which one will be clicked

So I have this line of code which as I understand it should accomplish what I want to do

mapView.identifyLayersWithMaxResults(mouse.x, mouse.y, 22, false, 1);

which should trigger in here

    onIdentifyLayerStatusChanged: {

      }

but instead what happens this line of code mapView.identifyLayersWithMaxResults(mouse.x, mouse.y, 22, false, 1);
crashes my app everytime

I was trying to follow the instructions per 
Identify features—ArcGIS Runtime SDK for Qt | ArcGIS for Developers

Identify features in all feature layers
When you do not know which specific layer to identify on, you can identify items in any layer in the map or scene. Change the first workflow above so that you do not specify the layer to identify. This time, the results are returned as a list of IdentifyLayerResult instead of a single result.
Layers that do not support identify or do not have any results based on the inputs are not included in the returned list.

Re: identifyLayersWithMaxResults crashes app

ErwinSoekianto — Thu, 25 Oct 2018 16:08:19 GMT

Kyle,

That is weird, are you running it in the AppStudio AppRun? AppStudio Player? What device(s) are you using?

Do you see any error message(s) in the console when the app crashes?

cc: ArcGIS Runtime SDK for Qt‌ , to see anyone in this group know anything about this specific issue.

Thank you,

Erwin

Re: identifyLayersWithMaxResults crashes app

LucasDanzinger — Thu, 25 Oct 2018 16:38:35 GMT

Based on this info, I don't know why it is crashing. But one thing to note is that you are calling identifyLayers with an "s" but your signal is set up for identifyLayer (singular). Instead it should be:

onIdentifyLayersStatusChanged: {

Re: identifyLayersWithMaxResults crashes app

KyleSchultz1 — Thu, 25 Oct 2018 16:48:28 GMT

It crashes in both App Studio Player and through the Qt creator debug mode

Re: identifyLayersWithMaxResults crashes app

LucasDanzinger — Thu, 25 Oct 2018 16:54:35 GMT

Can you get a call stack?

Re: identifyLayersWithMaxResults crashes app

KyleSchultz1 — Thu, 25 Oct 2018 17:00:49 GMT

no I cannot

Re: identifyLayersWithMaxResults crashes app

KyleSchultz1 — Thu, 25 Oct 2018 18:31:10 GMT

So I was running App Studio 3.053, upgraded to the latest release(3.1) and this solves my issue the crash stops and I'm able to get past to the onIdentifyLayersStatusChange event.

I do have a follow up question, is it possible to select a feature using this process as well? Since I don't know the feature layer its selecting and the only way I know how to select a feature is featureLayer.selectFeatures()

Re: identifyLayersWithMaxResults crashes app

ErwinSoekianto — Thu, 25 Oct 2018 20:56:19 GMT

So AppStudio 3.0 is running ArcGIS Runtime 100.2 and AppStudio 3.1 is running ArcGIS Runtime 100.3, it could be the reason.

Re: identifyLayersWithMaxResults crashes app

LucasDanzinger — Thu, 25 Oct 2018 21:36:07 GMT

the identify result gives access to the LayerContent, so that can be your layer for selecting. QML will implicitly cast LayerContent to FeatureLayer

Re: identifyLayersWithMaxResults crashes app

KyleSchultz1 — Sun, 12 Dec 2021 16:57:42 GMT

Just to make sure I'm understanding this correctly

anything retrieved by

 mapView.identifyLayersWithMaxResults()

will return in a variable defined like this

identifyLayersResults.geoElements

because so far any feature I click on returns empty or null variables

Re: identifyLayersWithMaxResults crashes app

KyleSchultz1 — Fri, 26 Oct 2018 17:23:28 GMT

Ok, I feel dumb now, as it clearly states in the documentation

identifyLayersResults is a list

so retrieving it would be

identifyLayersResults [0].geoElements[0]