Executing Dissolve method in ArcGIS Engine?

Question

I'm always having a problem in GP.execute() when trying to execute this method. Here is my code:

 Friend Function DissolveFeatures(ByVal pInFLayer As ESRI.ArcGIS.Carto.IFeatureLayer, ByVal DissolveField As String, ByVal OutName As String) As ESRI.ArcGIS.Carto.IFeatureLayer

            Dim GP As New ESRI.ArcGIS.Geoprocessor.Geoprocessor
            Dim Dissolve As ESRI.ArcGIS.DataManagementTools.Dissolve = New ESRI.ArcGIS.DataManagementTools.Dissolve
            Dim pFLayer As ESRI.ArcGIS.Carto.IFeatureLayer = New ESRI.ArcGIS.Carto.FeatureLayer

            Try
                GP.AddOutputsToMap = True
                GP.OverwriteOutput = True
                GP.SetEnvironmentValue("workspace", "Database Connections\IFE connexion.sde")

                Dissolve.in_features = pInFLayer
                Dissolve.dissolve_field = DissolveField
                Dissolve.out_feature_class = "Database Connections\IFE connexion.sde\" & OutName

                RunTool(GP, Dissolve, Nothing)


                pFLayer.FeatureClass = CType(GP.Open(OutName), IFeatureClass)
                pFLayer.Name = pFLayer.FeatureClass.AliasName

            Catch ex As Exception
                MsgBox(ex.Message & "Dissolve Features")
            End Try

            Return pFLayer

        End Function


Private Shared Sub RunTool(ByVal geoprocessor As ESRI.ArcGIS.Geoprocessor.Geoprocessor, ByVal process As IGPProcess, ByVal TC As ITrackCancel)

        ' Set the overwrite output option to true
        geoprocessor.OverwriteOutput = True

        Try
            geoprocessor.Execute(process, Nothing)
            ReturnMessages(geoprocessor)

        Catch err As Exception
            Console.WriteLine(err.Message)
            ReturnMessages(geoprocessor)
        End Try
    End Sub



    ' Function for returning the tool messages.
    Private Shared Sub ReturnMessages(ByVal gp As ESRI.ArcGIS.Geoprocessor.Geoprocessor)
        ' Print out the messages from tool executions
        Dim Count As Integer
        If gp.MessageCount > 0 Then
            For Count = 0 To gp.MessageCount - 1
                Console.WriteLine(gp.GetMessage(Count))
            Next
        End If
    End Sub

This returns an error:

Error HRESULT E_FAIL has been returned from a call to a COM component

Answer 1

I solved it. probleme is because you use iFeatureLayer as an input. Use a IFeatureClass.

 Friend Function DissolveFeatures(ByVal pFC As IFeatureClass, ByVal DissolveField As String, ByVal OutName As String) As iFeatureClass

        Dim GP As New ESRI.ArcGIS.Geoprocessor.Geoprocessor
        Dim Dissolve As ESRI.ArcGIS.DataManagementTools.Dissolve = New ESRI.ArcGIS.DataManagementTools.Dissolve

        Try

            Dissolve.in_features = pFC
            Dissolve.dissolve_field = DissolveField
            Dissolve.out_feature_class = "Database Connections\IFE connexion.sde\" & OutName

            RunTool(GP, Dissolve, Nothing)


            pFC.FeatureClass = CType(GP.Open(OutName), IFeatureClass)
            pFC.Name = pFC.FeatureClass.AliasName

        Catch ex As Exception
            MsgBox(ex.Message & "Dissolve Features")
        End Try

        Return pFC

    End Function