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Object = nothing?

Posted on 2002-03-05
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Last Modified: 2010-05-02
hi,

i use an optional argument in a method for my DLL,
this argument is an object (a progressbar)

how do i test if the programmer passed a progressbar, or didn't pass a progressbar?

Public Function TreeviewShowRecordsForAllTables(DatabaseName As String, Treeview As Object, Optional ProgresBar As Object)

if progresbar = nothing then
'does not work...


cheers
Ricky
0
Comment
Question by:Paurths
6 Comments
 
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Accepted Solution

by:
trkcorp earned 100 total points
ID: 6842562
if not OBJECT Is Nothing then
  'OBJECT Exists
Else
  'OBJECT is Nothing
End If
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LVL 2

Expert Comment

by:dirkmartin
ID: 6842571
use the following:

If IsMissing(ProgresBar)
0
 
LVL 15

Expert Comment

by:ameba
ID: 6842582
IsMissing is to be used if optional argument is declared As Variant.

Use what trkcorp said "if progresbar IS nothing"
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LVL 12

Expert Comment

by:jgv
ID: 6842632
If the parameter is a valid object, then you can also check that it reference's a progressbar:

Private Sub CheckIt(Optional objProgBar As Object)

    If objProgBar Is Nothing Then
        MsgBox "Parameter is missing"
        Exit Sub
    End If
   
    If Not TypeOf objProgBar Is ProgressBar Then
        MsgBox "Parameter is present, but not a progressbar"
        Exit Sub
    End If
   
    MsgBox "Parameter includes a progressbar"

End Sub
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LVL 12

Author Comment

by:Paurths
ID: 6842634
ok, excellent,

one more thing,
i am also passing a treeview

how do u clear a treeview? (remove all nodes)
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LVL 12

Author Comment

by:Paurths
ID: 6842648
clear  ofcourse...dumb of me...

cheers
Ricky
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