Selection sets

[Anonymous]

The routine below was developed to erase everything in a drawing and worked beautifully in windows7 but windows10 doesn't like the Set ssetObj = statement after CREATE_SET:

Public Sub ClearDrawing()
' Clears AutoCad drawing of all objects. Used in each connection module.

Dim ssetObj As AcadSelectionSet
       
    On Error GoTo CREATE_SET
        ThisDrawing.SelectionSets("MSset").Delete
    GoTo SKIP_CREATE_SET

CREATE_SET:
    
     Set ssetObj = ThisDrawing.SelectionSets.Add("MSset")

SKIP_CREATE_SET:

    If ThisDrawing.ModelSpace.Count > 0 Then
        ReDim ssobjs(0 To ThisDrawing.ModelSpace.Count - 1) As AcadEntity
        Dim i As Integer
        For i = 0 To ThisDrawing.ModelSpace.Count - 1
        Set ssobjs(i) = ThisDrawing.ModelSpace.Item(i)
    Next
        ssetObj.AddItems ssobjs
        ssetObj.Erase
    End If

End Sub

Error code is Run-time error '91':

Object variable or With block variable not set.

Any ideas?

[norman.yuan]

This line of code

CREATE_SET:
    
     Set ssetObj = ThisDrawing.SelectionSets.Add("MSset")

should not cause error of "Object varaiable or With block variable not set", be it running in Wndow7, 8 or 10.

From my observation, your code have logic error when the drawing DOES have a SelectionSet named "MSset" (for example, when you run your code the second time, because the first run creates the SelectionSet "MSset" and does not delete it).

Follow your code carefully:

1. When the drawing has a SelectionSet names as "MSset" (created by previous running your code), these lines of code executed correctly:

On Error GoTo CREATE_SET
        ThisDrawing.SelectionSets("MSset").Delete

GoTo SKIP_CREATE_SET

That is, the SelectionSet is deleted first, and then the next line asks the code to go to "SKIP_CREATE_SET" label, thus, these lines of code are skipped:

CREATE_SET:  
     Set ssetObj = ThisDrawing.SelectionSets.Add("MSset")

and directly go to the following If....End If. As you can see, in this case, ssetObj variable is NOT SET! So, this line of code raises the "91" error:

ssetObj.AddItems ssobjs

Excessively using GoTo labels in code is bad practice that leads to spaghetti code, difficult to read/follow/debug

[Anonymous]

Once you properly initialize the selectionset as told you by Norman, wouldn't it be simpler to use:

With ssetObj
.Select acSelectionSetAll
.Erase
End With