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Geoprocessing with objects/classes in .NET

AbelPerez

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?

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Accepted answers

CharlesMacleod

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:)

All comments

AbelPerez

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);

AbelPerez

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);

GKmieliauskas

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.

AbelPerez

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

CharlesMacleod

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:)

AbelPerez

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.

AbelPerez

@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.

AbelPerez

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);

AbelPerez

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

//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);

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