How to call a GP service from ArcObjects in .NET using ArcGIS Engine 10.2?

Question

I published and successfully accessed a GP service in ArcMap 10.2, but I couldn't make it work in my .NET program using ArcObjects 10.2:

        IGeoProcessor gp = new GeoProcessorClass();
        gp.AddToolbox(@"http://localhost:6080/arcgis/rest/services;mygpfolder/testsel");

        //input
        IGPUtilities2 gputils = new GPUtilitiesClass();
        IFeatureClass fc = (IFeatureClass)gputils.OpenDatasetFromLocation(@"E:\input.shp");
        IRecordSetInit recordset = new RecordSetClass();
        recordset.SetSourceTable((ITable)fc, null);
        IGPRecordSet gprecordset = new GPFeatureRecordSetLayerClass();
        gprecordset.RecordSet = (IRecordSet)recordset;

        IGPFeatureRecordSetLayer recordlayer = new GPFeatureRecordSetLayerClass();
        recordlayer = gprecordset as IGPFeatureRecordSetLayer;

        IVariantArray parameters = new VarArrayClass();
        parameters.Add(recordlayer);

        gp.Execute("Select", parameters, null);           

I got "Error HRESULT E_FAIL has been returned from a call to a COM component." at "gp.Execute". The GP service is published using tool "Select" under toolbox "Analysis" in ArcMap:

Any suggestions?

Answer 1

The tool is called Select_analysis, there are a few things called 'select' and you have to specify the one you want. The vague error doesn't help but it can't find a geoprocessing tool called 'select'.

gp.Execute("Select_analysis", parameters, null);

it may be worth noting that a geoprocessor tool returns a value of type IGeoProcessorResult which you can get your messages using GetResultMessages. This will at least give you some inkling why the tool failed.