topic Re: Empty Void Null Selection Set in VBA Forum

Empty Void Null Selection Set

Anonymous — Fri, 03 Sep 2004 15:14:40 GMT

How do you test if the Selection Set contains anything nothing

In particular:

Dim oEnt As AcadEntity
For Each oEnt In ThisDrawing.ActiveSelectionSet
Process (oEnt)
Next

I get an error if there is nothing in the active selection set
I can't do
ThisDrawing.ActiveSelectionSet.Count
Because it also causes an error.

Thanks!
Nathan

Re: Empty Void Null Selection Set

Anonymous — Fri, 03 Sep 2004 15:33:01 GMT

If ThisDrawing.ActiveSelectionSet.Count > 0 -- ---- Ed ---- "ndog" wrote in message news:24754369.1094224510450.JavaMail.jive@jiveforum1.autodesk.com... > How do you test if the Selection Set contains anything nothing > > In particular: > > Dim oEnt As AcadEntity > For Each oEnt In ThisDrawing.ActiveSelectionSet > Process (oEnt) > Next > > I get an error if there is nothing in the active selection set > I can't do > ThisDrawing.ActiveSelectionSet.Count > Because it also causes an error. > > Thanks! > Nathan

Re: Empty Void Null Selection Set

Anonymous — Fri, 03 Sep 2004 16:48:17 GMT

I tried your method

If ThisDrawing.ActiveSelectionSet.Count > 0 Then
...

But get same error as before when there is no active selection:

Run-time error '-2145320949 (8021000b)':
Calling method AddItems of Interface IAcadSelectionSet failed

Thanks for the suggestion,

Nathan

Re: Empty Void Null Selection Set

Anonymous — Fri, 03 Sep 2004 21:40:55 GMT

Hi, While stepping through your code hold the cursor over the selection set and you will see its current value - or nothing if it holds data. Or do a quick view of it. You could decide to let the error occur and deal with it by using an "on error resume next" -- Laurie Comerford CADApps www.cadapps.com.au -- Laurie Comerford CADApps www.cadapps.com.au "ndog" wrote in message news:24754369.1094224510450.JavaMail.jive@jiveforum1.autodesk.com... > How do you test if the Selection Set contains anything nothing > > In particular: > > Dim oEnt As AcadEntity > For Each oEnt In ThisDrawing.ActiveSelectionSet > Process (oEnt) > Next > > I get an error if there is nothing in the active selection set > I can't do > ThisDrawing.ActiveSelectionSet.Count > Because it also causes an error. > > Thanks! > Nathan

Re: Empty Void Null Selection Set

Anonymous — Tue, 07 Sep 2004 05:42:34 GMT

Do your drawing in which you are working uses a custome object? If yes then there is a changes that your object(dbx) is not loaded in the AutoCAD fully. Some times ago I had the same problem and I found that it worked properly after the dbx was loaded. I my case I was getting the error even if I was trying to access a valid item from the selection set. The probable solution to your problem is that if the custom object is yours the change the demand loading option so that it is automatically loaded when AutoCAD starts. Normally what happens that we program so that the arx or dbx is loaded if a command is invoked which defined in that arx or there is an entity defined by the dbx then it loads.

I hope this will solve your problem.

Manoj

Re: Empty Void Null Selection Set

Anonymous — Tue, 07 Sep 2004 17:23:05 GMT

Try this texst: Sub testAS() Dim ss As AcadSelectionSet Set ss = ThisDrawing.ActiveSelectionSet If ss.Count > 0 Then MsgBox "ss count = " & ss.Count Else MsgBox "There is no Acitive selection set." 'create a new selection set. Set ss = AddSelectionSet "newSS" 'ss.AddItems() 'or 'ss.SelectOnScreen() End If End Sub Public Function AddSelectionSet(SetName As String) As AcadSelectionSet ' This routine does the error trapping neccessary for creating selection sets. On Error Resume Next Set AddSelectionSet = ThisDrawing.SelectionSets.Add(SetName) If Err.Number <> 0 Then Set AddSelectionSet = ThisDrawing.SelectionSets.Item(SetName) End If End Function Your error message does not say that there the problem is that there is no selection set. It says you tried to use the AddItems method and it failed. You need to properly handle the situation where no ActiveSelectionSet exists. In the previous example, I used an If statement to decide what to do based on the Count property. If there are items selected already, the Count will be greater than 0. If it's zero, the selection set doesn't exist and you can't go ahead and AddItems to a selection set that doesn't exist. So create one and then add to it. -- ---- Ed ---- "ndog" wrote in message news:814807.1094230128155.JavaMail.jive@jiveforum1.autodesk.com... > I tried your method > > If ThisDrawing.ActiveSelectionSet.Count > 0 Then > .. > > But get same error as before when there is no active selection: > > Run-time error '-2145320949 (8021000b)': > Calling method AddItems of Interface IAcadSelectionSet failed > > Thanks for the suggestion, > > Nathan