topic Re: ARCGIS 10, VB.NET, calculate centroids in Developers Questions

ARCGIS 10, VB.NET, calculate centroids

BrunoVincent — Fri, 17 Jun 2016 09:08:56 GMT

Hello,

I have migrated an toolbar initially developped for ArcGis 9,3. This tool is used by non-programmer or cartographers.

One procedure is called to generate centroids of attributes table and after to launch an calculation.

Anyway,

The source code used in 9,3 was :

(A)

'instantiating new calculator and cursor

pCalculator = New Calculator

pCursor = CType(pFeatureClass.Update(Nothing, True), ICursor)

'Centroid Y

With pCalculator

.Cursor = pCursor

.PreExpression = "Dim pGeomShp as IGeometry" & vbNewLine & "Set pGeomShp = [shape]" & vbNewLine & "Dim pArea as IArea" & vbNewLine & "Set pArea = pGeomShp" & vbNewLine

.Expression = "pArea.Centroid.Y"

.Field = "centroidY"

End With

'try & catch *************************************************

Try

pCalculator.Calculate()

Catch ex As System.Exception

MessageBox.Show("Error: " + ex.Message)

End Try

This was working until moving to ArcGis 10 (an upper). A crash was observed while launching pCalculator.Calculate().

I’ve migrated this code that way (like proposed here http://gis.stackexchange.com/questions/52983/syntax-for-arcgis-icalculator-object/198681#198681 ) :

(B)

Dim nCentroidXFieldIndex As Integer = pFeatureClass.FindField("centroidX")

Dim nCentroidYFieldIndex As Integer = pFeatureClass.FindField("centroidY")

Dim nBldg_sizeFieldIndex As Integer = pFeatureClass.FindField("Bldg_size")

If TypeOf pFeatureClass Is IFeatureClass Then

If TypeOf pFeatureCursor Is IFeatureCursor Then

Dim pArea As IArea

Dim pFeature As IFeature = pFeatureCursor.NextFeature()

Dim myProgressCalc As New FileProgressForm

myProgressCalc.set_maximum(iTotalRecords)

myProgressCalc.Show()

myProgressCalc.Text = "Veuillez patienter svp"

myProgressCalc.lblProgress.Text = "Calcul des données géographiques"

myProgressCalc.Update()

pArea = CType(pFeature.Shape, IArea)

While pFeature IsNot Nothing

pFeature.Value(nCentroidXFieldIndex) = pArea.Centroid.X

pFeature.Value(nCentroidYFieldIndex) = pArea.Centroid.Y

pFeature.Value(nBldg_sizeFieldIndex) = pArea.Area

pFeature.Store()

pFeature = pFeatureCursor.NextFeature

myProgressCalc.Go()

End While

myProgressCalc.Close()

End If

It’s working but it’s working extremely slowly ! The first code (A) was executed in less than 3 minutes. The new one (B) in 25 minutes !

In fact, I just want to programmaticaly call a the new calculate geometry tool (when displaying attributes table - http://desktop.arcgis.com/fr/arcmap/10.3/manage-data/tables/calculating-area-length-and-other-geometric-properties.htm )

Screen capture 1

Too bad, can't upload PNG and JPEG files...

or Arc tool => Data Management Tools => Entities => Add geometric attributes (http://pro.arcgis.com/fr/pro-app/tool-reference/data-management/add-geometry-attributes.htm )

Screen capture 2

or any other methods !

Both tools are working great in ArcGis Desktop but I can’t find my way to make them work in VB.NET.

Please, any suggestions ? (It’s just driving me crazy).

Thanks by advance for your answer, and sorry for screen capture in french and for poor english speaking

Matthieu

Re: ARCGIS 10, VB.NET, calculate centroids

KenBuja — Fri, 17 Jun 2016 14:58:08 GMT

One issue with your ICalculate PreExpression script is with ArcGIS 10, VBScript will now crash when try to declare a variable as a type.

Dim pGeomShp as IGeometry

should be replaced with

Dim pGeomShp

Re: ARCGIS 10, VB.NET, calculate centroids

BrunoVincent — Mon, 20 Jun 2016 11:58:03 GMT

Hello,

Thank you.

I just made the change you proposed without any success.

The following error is still showing :

"Error -2147467259 HRESULT E_FAIL has been returned from a call to a COM component"

Re: ARCGIS 10, VB.NET, calculate centroids

KenBuja — Mon, 20 Jun 2016 15:27:45 GMT

Did you also make that change to the Dim pArea line? Also, have you tried running the PreExpression script manually in the Field Calculator?

Re: ARCGIS 10, VB.NET, calculate centroids

BrunoVincent — Tue, 21 Jun 2016 10:34:47 GMT

Hello,

Yes, I also made the change for the "Dim pArea" line. With no success.

I tried to execute this code manually in ArcGis desktop. But unfortunately, it did'nt work. I'm realizing that I should write the good script here before trying to program it.

I made many tries in VB. Tthe only thing that were working correctly (manually, in desktop ) was in Python with that code :

!shape.centroid.X!

But I just can't make it work in the program.

Re: ARCGIS 10, VB.NET, calculate centroids

KenBuja — Wed, 22 Jun 2016 21:05:10 GMT

Unfortunately, there's a bug with the ICalculator (#NIM061356) that doesn't allow it to use Python syntax. This has been around since 2010 and while it's classified as High Severity, they still haven't fixed it.

Re: ARCGIS 10, VB.NET, calculate centroids

BrunoVincent — Thu, 23 Jun 2016 08:51:59 GMT

Damn.

It's so easy to make it work in Python with 1 line of code and I can't make it with VBScript ...