topic Re: Geoprocessing with objects/classes in .NET in ArcGIS Pro SDK Questions

Geoprocessing with objects/classes in .NET

AbelPerez — Sat, 20 Aug 2022 22:58:11 GMT

With Pro 3.0 I am trying to implement the SelectLayerByLocation geoprocessing tool. I have objects/classes that I want to pass in to the tool. I've looked at the community samples and the ESRI forums and I must be missing something because this throws an exception

System.InvalidOperationException
HResult=0x80131509
Message=convert unsupported type
Source=ArcGIS.Desktop.GeoProcessing

object[] listOfParameter = { SelectedProximityLayer, "WITHIN_A_DISTANCE_GEODESIC", featOrigin, "100 NAUTICALMILES", "NEW_SELECTION", "NOT_INVERT" }; var parameters = Geoprocessing.MakeValueArray(listOfParameter); //exception here var gpResult = await Geoprocessing.ExecuteToolAsync("SelectLayerByLocation_management", parameters);

With ArcMap you could call out a native .NET API to do this and I can't find anything similar with Pro:

Dim selLyrLoc As New SelectLayerByLocation selLyrLoc.in_layer = pPointProxLayer 'the selection will be applied to this layer selLyrLoc.overlap_type = "WITHIN_A_DISTANCE_GEODESIC" 'we want features within a geodesic distance selLyrLoc.select_features = pFeatSelOrigin 'this is the source feature selLyrLoc.search_distance = "100 NAUTICALMILES" 'search within 100 NM of the source selLyrLoc.selection_type = "NEW_SELECTION" 'new selection selLyrLoc.invert_spatial_relationship = "NOT_INVERT" 'do not invert selection 'run the geoprocessor Dim res As ESRI.ArcGIS.Geoprocessing.IGeoProcessorResult = CType(GP.Execute(selLyrLoc, Nothing), ESRI.ArcGIS.Geoprocessing.IGeoProcessorResult)

I see that the parameter list is a string list but how do I feed my objects /classes to any geoprocessing tool?

Re: Geoprocessing with objects/classes in .NET

AbelPerez — Sun, 21 Aug 2022 18:38:55 GMT

After looking at the documentation and my prior work with ArcMap I see where I erred. The parameter Selecting Features is defined as a Feature Layer and I was trying to pass it a Feature object. All I had to do was select my feature in the layer and pass it the layer like so:

//clear the origin layer of ALL selections SelectedOriginLayer.ClearSelection(); //select ONLY the origin feature in the origin layer var qf = new QueryFilter(); qf.WhereClause = "FID=1"; Selection selOrigin = SelectedOriginLayer.Select(qf, SelectionCombinationMethod.New); //clear the proximity layer of ALL selections SelectedProximityLayer.ClearSelection(); //gp List<object> values = new List<object>(); values.Add(SelectedProximityLayer); //in_layer: the selection will be applied to this layer values.Add("WITHIN_A_DISTANCE_GEODESIC"); //overlap_type: we want features within a geodesic distance values.Add(SelectedOriginLayer); //select_features: this is the source (the original) values.Add("100 NAUTICALMILES"); //search_distance: search within 100 NM of the source values.Add("NEW_SELECTION"); //selection_type: new selection values.Add("NOT_INVERT"); //invert_spatial_relationship: do not invert selection var parameters = Geoprocessing.MakeValueArray(values); IGPResult gpResult = await Geoprocessing.ExecuteToolAsync("SelectLayerByLocation_management", parameters);

Re: Geoprocessing with objects/classes in .NET

AbelPerez — Sun, 21 Aug 2022 23:02:17 GMT

Unfortunately it didn't work. I have been trying for 2 days to get this to work and its a bit disappointing to me that at Pro 3.0 that geometry objects are not supported with geoprocessing. At least the ones I have tested. This is what ended up working for me after numerous tests (why are we still relying on strings when we have classes and objects?):

//clear the origin layer of ALL selections SelectedOriginLayer.ClearSelection(); //select ONLY the origin feature in the origin layer var qf = new QueryFilter(); qf.WhereClause = "FID=1"; Selection selOrigin = SelectedOriginLayer.Select(qf, SelectionCombinationMethod.New); //clear the proximity layer of ALL selections SelectedProximityLayer.ClearSelection(); //gp List<string> vals= new List<string>(); vals.Add(SelectedProximityLayer.URI); //in_layer: the selection will be applied to this layer vals.Add("WITHIN_A_DISTANCE_GEODESIC"); //overlap_type: we want features within a geodesic distance vals.Add(SelectedOriginLayer.URI); //select_features: this is the source (the original) vals.Add("100 NAUTICALMILES"); //search_distance: search within 100 NM of the source vals.Add("NEW_SELECTION"); //selection_type: new selection vals.Add("NOT_INVERT"); //invert_spatial_relationship: do not invert selection IGPResult gpResult = await Geoprocessing.ExecuteToolAsync("SelectLayerByLocation_management", vals);

Re: Geoprocessing with objects/classes in .NET

GKmieliauskas — Mon, 22 Aug 2022 05:51:46 GMT

The way to set geoprocessing parameters is like this:

var parameters = Geoprocessing.MakeValueArray(SelectedProximityLayer, "WITHIN_A_DISTANCE_GEODESIC", featOrigin, "100 NAUTICALMILES", "NEW_SELECTION", "NOT_INVERT");

There is no need to form object or string array. Geoprocessing MakeValueArray knows how to convert each parameter depending on it type.

Re: Geoprocessing with objects/classes in .NET

AbelPerez — Mon, 22 Aug 2022 16:04:55 GMT

@GKmieliauskas that is exactly what I have in my original post. It doesnt work. I also posted the error.

Re: Geoprocessing with objects/classes in .NET

CharlesMacleod — Mon, 22 Aug 2022 19:33:58 GMT

Abel, Looking at the tool help regarding input parameters, as written, this does looks correct to me also

//gp List<string> vals= new List<string>(); vals.Add(SelectedProximityLayer.URI); vals.Add(...); ... await Geoprocessing.ExecuteToolAsync("SelectLayerByLocation_management", parameters)

Here is my stab at this (which does work for me):

Given these inputs (using Crimes and Fire stations point data sets from the community samples data):

I have this code - as Gintatuatas mentioned I just pass the param values straight to MakeValueArray:

internal class TestGP : Button { protected async override void OnClick() { var sel_tool_name = "SelectLayerByLocation_management"; var input_layer = MapView.Active.Map.GetLayersAsFlattenedList() .OfType<FeatureLayer>().FirstOrDefault(l => l.Name == "Crimes"); if (input_layer == null) return; var sel_layer = MapView.Active.Map.GetLayersAsFlattenedList() .OfType<FeatureLayer>().FirstOrDefault(l => l.Name == "Fire_Stations"); if (sel_layer == null) return; var parameters = Geoprocessing.MakeValueArray( input_layer, "WITHIN_A_DISTANCE_GEODESIC", sel_layer, "1000 Feet", "NEW_SELECTION", "NOT_INVERT"); await Geoprocessing.ExecuteToolAsync(sel_tool_name, parameters); //test params by showing the tool dialog //await Geoprocessing.OpenToolDialogAsync(sel_tool_name, parameters); }

(these are my parameters returned from Geoprocessing.MakeValueArray:)

Re: Geoprocessing with objects/classes in .NET

AbelPerez — Mon, 22 Aug 2022 23:15:19 GMT

Let me test this. The only difference I see is that I am using BasicFeatureLayer. Not sure why though. I think the example I was following used that class. Now that I look at the differences, the FeatureLayer class has more methods. So let me change to that class and test again.

Re: Geoprocessing with objects/classes in .NET

AbelPerez — Tue, 23 Aug 2022 23:13:29 GMT

@GKmieliauskas @CharlesMacleod well that seemed to work. thanks!!!

The only thing I did different was change my classes from BasicFeatureLayer to FeatureLayer.
I wonder if the GP tools just dont work with the BasicFeatureLayer class.

Re: Geoprocessing with objects/classes in .NET

AbelPerez — Tue, 23 Aug 2022 23:28:36 GMT

Actually I found the possible source of all my problems. I suspect that many other devs might also make this simple mistake. The function MakeValueArray takes as its input a variable number of objects as an array. I thought that if i passed it a List of Objects it would work as well. It does compile so merrily I went along. However, it is reading the List of Objects as a single object. What I needed to do was convert that List of Objects to an Array of objects AND then pass that to the GP tool.

Example:

//create the parameter list for the GP List<object> vals = new List<object>(); vals.Add(lyrProximity); //in_layer: the selection will be applied to this layer vals.Add("WITHIN_A_DISTANCE_GEODESIC"); //overlap_type: we want features within a geodesic distance vals.Add(lyrOrigin); //select_features: this is the source vals.Add(radiusInNm.ToString() + " NAUTICALMILES"); //search_distance: search within xNM of the source vals.Add("NEW_SELECTION"); //selection_type: new selection vals.Add("NOT_INVERT"); //invert_spatial_relationship: do not invert selection //var parameters = Geoprocessing.MakeValueArray(vals); //compiles but does not work var parameters = Geoprocessing.MakeValueArray(vals.ToArray()); //compiles and works IGPResult gpResult = await Geoprocessing.ExecuteToolAsync("SelectLayerByLocation_management", parameters);

Re: Geoprocessing with objects/classes in .NET

AbelPerez — Tue, 23 Aug 2022 23:31:50 GMT

Actually I found the possible source of all my problems. I suspect that many other devs might also make this simple mistake.