working with selection set filters

I am currently using a loop on all entities in a map to look for entities with certain properties, like this:

For Each oAcadObj In ThisDrawing.ModelSpace
'''Look for entities with certain properties, write out some info
Next

My processing is kind of slow, and I was thinking that to speed it up, I might be able to restrict my search to entities of certain object types, or which are on certain layers, etc. I haven't used selection sets before, but I'd like to at least try this out and do some timing comparisons to see if this is worth doing or not. I've been looking at some examples, but I'm still having some trouble with this. Let's say I want to loop on only entities which are Lines or Polylines (object type AcDbLine or AcDbPolyline). This is what I'm trying to do, but it's not working (nothing is getting selected):

Dim ssLines As AcadSelectionSet
Dim GroupCode(0 To 1) As Integer
Dim DataValue(0 To 1) As Variant

Set ssLines = ThisDrawing.SelectionSets.Add("SS1")
GroupCode(0) = 0
DataValue(0) = "Line"
GroupCode(1) = 0
DataValue(1) = "Polyline"

'''''Or I also tried doing it this way, which I had also seen in an example
'''''''GroupCode(0) = 0: DataValue(0) = "Line,Polyline"

ssLines.Select acSelectionSetAll, , , GroupCode, DataValue

For Each oAcadObj In ssLines
'''Look for entities with certain properties, write out some info
Next


For the DataValue, in addition to "Polyline", I also tried "AcDbPolyline" and other things. From the examples I saw, I thought that it should be "Line" and "Polyline", but I'm not really sure.

I'm sure I'm doing something really stupid. Any help in pointing it out would be much appreciated

 

Here's some code that's been floating around for a while for your selection set creation:

Code:

'Simple sel set object creation function.
'vba will return an error if the sel set object already exists
'in the SSETS collection
Public Function vbdPowerSet(strName As String) As AcadSelectionSet
Dim objSelSet As AcadSelectionSet
Dim objSelCol As AcadSelectionSets
Set objSelCol = ThisDrawing.SelectionSets
For Each objSelSet In objSelCol
If objSelSet.Name = strName Then
objSelCol.Item(strName).Delete
Exit For
End If
Next
Set objSelSet = objSelCol.Add(strName)
Set vbdPowerSet = objSelSet
End Function

(usage:
'create a new selection set object
Set ssetObj = vbdPowerSet("SS01")
)

 

Hi Mandy,

Most likely you are running into a non-intuitive aspect of Selection Sets
The line below can only work once:
Set ssLines = ThisDrawing.SelectionSets.Add("SS1")
Each time you try run it after that you have to clear the error and continue
the program running. There are all sorts of approaches to this problem.

The one I use is shown below:
''''''''''''''''''''''''''''''''''''''''''''''''''
' Create a selection set of objects on selected Layer
'Call with:
'Dim ssObjects As AcadSelectionSet
'Dim iTmp As Integer
'sObjectType = "LWPOLYLINE" ' Object type
''sLayer = "Text" ' Object layer
'iTmp = SelectObjectsOnLayer(ssObjects, spObjectType, spLayer)
Sub ssTest()
Dim lTmp As Long
Dim ssObjects As AcadSelectionSet
lTmp = SelectObjectsOnLayer(ssObjects, "LWPOLYLINE", "TEXT")
or
If SelectObjectsOnLayer(ssObjects, "LINE", "TEXT") > 0 then
DoSomething
else
Exit Sub
End if
End Sub ' ssTest()
''''''''''''''''''''''''''''' '''''''''''''''''''
Public Function SelectObjectsOnLayer(ssObs As AcadSelectionSet, spObjectType
As String, spLayer As String) As Long
On Error Resume Next
Dim FilterType(0 To 1) As Integer
Dim FilterData(0 To 1) As Variant
Dim sNumber As String
FilterType(0) = 0: FilterData(0) = spObjectType
FilterType(1) = 8: FilterData(1) = spLayer
' The line below will create an error if the SSET doesn't exist
' or delete it if it does exist.
' The ON Error will allow the program to continue and create the set
ThisDrawing.SelectionSets.Item("SSET").Delete
Set ssObs = ThisDrawing.SelectionSets.Add("SSET")
ssObs.Select acSelectionSetAll, , , FilterType, FilterData
SelectObjectsOnLayer = ssObs.Count
Exit Function
SOLErrorHandler:
Err.Clear
SelectObjectsOnLayer = 0
End Function ' SelectObjectsOnLayer()

For passing data, you can use "LINE,POLYLINE,TEXT" to get Lines, Polylines
and Text
You can use any wildcards for the layers. An asterisk gets data from all
layers.

--


Laurie Comerford
CADApps
www.cadapps.com.au

with certain properties, like this:

might be able to restrict my search to entities of certain object types, or
which are on certain layers, etc. I haven't used selection sets before, but
I'd like to at least try this out and do some timing comparisons to see if
this is worth doing or not. I've been looking at some examples, but I'm
still having some trouble with this. Let's say I want to loop on only
entities which are Lines or Polylines (object type AcDbLine or
AcDbPolyline). This is what I'm trying to do, but it's not working (nothing
is getting selected):

and other things. From the examples I saw, I thought that it should be
"Line" and "Polyline", but I'm not really sure.

would be much appreciated

 

Thanks for the help.

Actually, there must just be something strange about Polylines. I was just doing some little tests, and if I just filter on Lines, or just on Text, it works fine. But as soon as I set the filter to Polyline, I get nothing selected. I KNOW the drawing has polylines in it.

Any idea what the problem might be?

 

Are they Polylines or LWPolylines?

 

Are they LWPOLYLINE's.
Regards - Nathan

 

This works for me, selecting either style of 2d polyline.

FilterType(0) = 0: FilterData(0) = "POLYLINE,LWPolyline"

Jon

just doing some little tests, and if I just filter on Lines, or just on
Text, it works fine. But as soon as I set the filter to Polyline, I get
nothing selected. I KNOW the drawing has polylines in it.

 

As a by the way:
I test the returned entity to determine whether the polyline points list is
a 3d array or 2d array with:

If filterent.ObjectName = "AcDbPolyline" Then
numvert = 2
Else
numvert = 3
End If

which comes into play as I step thru the vertices:
vPt = filterent.Coordinates ' array of coords

For i = 0 To ((UBound(vPt) + 1) / numvert) - 1
pickpt = Array(vPt(i * numvert), vPt(i * numvert + 1))
....

Jon

 

Thanks for the help everyone, and all the tips. I think I've got it working now.