CODEWITHSUNDEEP
ms-access
BWhite
BWhite

Reputation: 853

Reference Parent property

I have a form that in certain situations doesn't have a parent.
Then it fails to open.
So I wrap it in an 'if'
It still fails to open.

Private Sub Form_Open(Cancel As Integer)
    If Not Parent Is Nothing Then  << Error
        Me!Button1.Enabled = Not (Nz(Parent!Lock, 0))
        Me!Button2.Enabled = Not (Nz(Parent!Lock, 0))
    End If
End Sub

gives "Run-time error '2452': The expression you entered has an invalid reference to the Parent property."
But if I declare the variable, then the original code won't work.

Upvotes: 1

Views: 63

Answers (1)

Erik A
Erik A

Reputation: 32642

This is a tricky one, as if the form has no parent, any access to the property (even testing if it's empty) will trigger an error.

The easiest workaround is testing using error trapping:

Public Function HasParent(obj As Object) As Boolean
    On Error GoTo ExitFunction
    If Not obj.Parent Is Nothing Then
        HasParent = True
    End If
ExitFunction:
End Function

Private Sub Form_Open(Cancel As Integer)
    If HasParent(Me) Then 
        Me!Button1.Enabled = Not (Nz(Parent!Lock, 0))
        Me!Button2.Enabled = Not (Nz(Parent!Lock, 0))
    End If
End Sub

Upvotes: 1

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