New Post: Shapefie.Categories.Generate crashes with large files

Hello everybody,

I use the following code in my MS-Access/Vba GIS application to clear a selection:

Public Sub clearSelection()
    ' Selection zurücksetzen
    
    Dim objShape As MapWinGIS.Shapefile
    Dim objOptions As MapWinGIS.ShapeDrawingOptions
    Dim lngLayerHandle As Long
    Dim varShapeIDs As Variant
    Dim lngShapeIndex As Long
    Dim i As Long
    
    ' get handle of active layer
    lngLayerHandle = colLayers(Me.lstProject.SelectedItem.Key).layerHandle
    ' create layerobject
    Set objShape = Me.mapMain.GetObject(lngLayerHandle)
    ' create index on the first column
    REM this line produces an out of stack space error with large files
    objShape.Categories.Generate 0, ctUniqueValues, 0
    ' get selected items
    objShape.SelectShapes Me.mapMain.Extents, 0, INTERSECTION, varShapeIDs
    objShape.Categories.ApplyExpressions
    ' iterate over selected items
    For i = 0 To UBound(varShapeIDs)
        ' get shapeindex of current item
        lngShapeIndex = objShape.ShapeCategory(varShapeIDs(i))
        ' reset fill color
        objShape.Categories.Item(lngShapeIndex).DrawingOptions.fillColor = _
            colLayers(Me.lstProject.SelectedItem.Key).fillColor
    Next i
    Me.mapMain.Redraw
End Sub

If the shapefile has a large number of Elements, in one case nearly 46,000 elements, the line:

objShape.Categories.Generate 0, ctUniqueValues, 0

leads to an error (28 - out of stack space).

I use index creation on several places in my code.

Is there a workaround?

Thanks and regards