topic Re: Geoprocessing Async Error in ArcGIS Pro SDK Questions

Geoprocessing Async Error

tzz_12 — Thu, 13 Apr 2023 17:01:01 GMT

I am trying to run a few geoprocessing methods in the sequence they occur. It works fine if I just keep it simple, but I want to add some additional parameters, such as environment and GPExecuteToolFlags. There is an errors that states the "Object reference is not set to an instance of an object." Please see my code below.

Thanks for your help!

Re: Geoprocessing Async Error

GKmieliauskas — Thu, 13 Apr 2023 06:29:21 GMT

Hi,

I think problem with line:

var Agg_para = Geoprocessing.MakeValueArray(intersectFC, intersectSortFC, GPRun("management.Sort", Agg_para, null,null,outputOnMapNone);

You use Agg_para parameter without initialization in running management.Sort tool

Re: Geoprocessing Async Error

Wolf — Thu, 13 Apr 2023 16:31:03 GMT

Your code snippet has a problem, this line doesn't make much sense when GPRun returns void, plus a closing ')' is missing:

var Agg_para = Geoprocessing.MakeValueArray(intersectFC, intersectSortFC, GPRun("management.Sort", Agg_para, null,null,outputOnMapNone);

i would suggest setting a breakpoint before you call Geoprocessing.ExecuteToolAsync and inspect the content of the parameters array to make sure the content looks correct. If you run the same GP tool manually you can look at the corresponding python command to get the proper parameter sequence for the input parameters array.

Re: Geoprocessing Async Error

tzz_12 — Thu, 13 Apr 2023 17:12:52 GMT

Hi Wolf,

When I copy and paste the code into the post, I had to fix the formatting of the code, and I accidently deleted some parts of the code by accident. Here is the code for the sort geoprocessing method below. The error, "NullReferenceException: Object reference is not set to an instance of an object.", occurred in the GPRun method, when it calls the Geoprocessing.ExecuteToolAsync.

var Agg_para = Geoprocessing.MakeValueArray(intersectFC, intersectSortFC, AggregateField); utility.GPRun("management.Sort", Agg_para);

Re: Geoprocessing Async Error

Wolf — Thu, 27 Apr 2023 17:52:35 GMT

Sorry about the delay. I noticed a problem with the variation of "Geoprocessing.ExecuteToolAsync" that you are using. It turns out that the 'progressor' parameter cannot be null.

You can create a Progressor using this snippet:

CancelableProgressorSource cps = new CancelableProgressorSource("Run GP", "Canceled"); var progressor = cps.Progressor;

This variation of your code worked for me:

protected async override void OnClick() { try { var intersectInputLyr1 = MapView.Active.Map.GetLayersAsFlattenedList().OfType<FeatureLayer>().Where(fl => fl.Name.Equals("TestPolygons")).FirstOrDefault(); var intersectInputLyr2 = MapView.Active.Map.GetLayersAsFlattenedList().OfType<FeatureLayer>().Where(fl => fl.Name.Equals("TestLines")).FirstOrDefault(); var intersectOutputFC = System.IO.Path.Combine(Project.Current.DefaultGeodatabasePath, "IntersectFc"); var intersectOutputSortFC = System.IO.Path.Combine(Project.Current.DefaultGeodatabasePath, "IntersectSortFc"); var AggregateField = "Description"; CancelableProgressorSource cps = new CancelableProgressorSource("Run GP", "Canceled"); var in_features = new List<FeatureLayer>() { intersectInputLyr1, intersectInputLyr2 }; var argsSortedIntersect = Geoprocessing.MakeValueArray(in_features, intersectOutputFC, "ALL",//join_attributes = "ALL", null,//cluster_tolerance = None, "INPUT"//output_type = "INPUT" ); GPExecuteToolFlags noMapOutput = GPExecuteToolFlags.None; // set overwrite flag var env = Geoprocessing.MakeEnvironmentArray(overwriteoutput: true); await GPRun("analysis.Intersect", argsSortedIntersect, env, cps.Progressor, noMapOutput); var Agg_para = Geoprocessing.MakeValueArray(intersectOutputFC, intersectOutputSortFC, AggregateField); await GPRun("management.Sort", Agg_para, env, cps.Progressor); var intersectInputLyr3 = MapView.Active.Map.GetLayersAsFlattenedList().OfType<FeatureLayer>().Where(fl => fl.Name.Equals("TestPoints")).FirstOrDefault(); var intersectOutputFc2 = System.IO.Path.Combine(Project.Current.DefaultGeodatabasePath, "IntersectPointFc"); var in_features2 = new List<FeatureLayer>() { intersectInputLyr3, intersectInputLyr2 }; var argsIntersect2 = Geoprocessing.MakeValueArray(in_features2, intersectOutputFc2); GPExecuteToolFlags flag = GPExecuteToolFlags.GPThread; await GPRun("analysis.Intersect", argsIntersect2, env, cps.Progressor, flag); } catch (Exception ex) { MessageBox.Show($@"Exception: {ex.ToString()}"); } } public async Task GPRun(string GPTool, IReadOnlyList<string> parameters, IEnumerable<KeyValuePair<string, string>> env = null, CancelableProgressor prog = null, GPExecuteToolFlags flag = GPExecuteToolFlags.Default) { try { var gp_result = await Geoprocessing.ExecuteToolAsync(GPTool, parameters, env, prog, flag); if (gp_result != null) Geoprocessing.ShowMessageBox(gp_result.Messages, "Geoprocessing Result", gp_result.IsFailed ? GPMessageBoxStyle.Error : GPMessageBoxStyle.Default); } catch { var gp_result = await Geoprocessing.OpenToolDialogAsync(GPTool, parameters, env); if (gp_result != null) Geoprocessing.ShowMessageBox(gp_result.Messages, "Geoprocessing Result", gp_result.IsFailed ? GPMessageBoxStyle.Error : GPMessageBoxStyle.Default); } }