Page 256 line 16 Invalid use of Null

Noodude · November 23rd, 2012, 05:15 PM

Hey all,

I am learning VBA for the company I work for an I am running into issues with the practice code. I have copied the code exactly as it is shown in the book to the best of my copying abilities. I continue to get a runtime error 94 which is an invalid use of Null. I tried using Notepad++ to compare the example code that I downloaded off the website and they are identical. Here and a snippet of my code and the example give with my code's incorrect code supposedly.

My code...

Code:

Option Compare Database
Option Explicit

 'Declare the object variable using WithEvents
Private WithEvents Dlg As Form_DlgMyDialog

Private Sub cmdClose_Click()
    DoCmd.Close acForm, Me.Name
End Sub

Private Sub cmdSelect_Click()
    'Instantiate the dialog
    Set Dlg = New Form_DlgMyDialog
    
    'Enable the appropriate combo
    Dlg.WhichOne = Me.optMyOptionGroup
    
    'If we had declared dialog properties, we
    'could pass their values here:
    'Dlg.Property1 = 123
    'Dlg.Property2 = "some value"
    'etc...
    
    'Show the dialog
    Dlg.Visible = True
End Sub

Private Sub Dlg_Finished(varReturn As Variant)
    Me.txtMyTextBox.Enabled = (Not IsNull(varReturn))
    
    If Not IsNull(varReturn) Then
        Me.txtMyTextBox = varReturn
    End If
End Sub

Private Sub Form_Unload(Cancel As Integer)
    'Clean Up
    Set Dlg = Nothing
End Sub

Example code...

Code:

Option Compare Database
Option Explicit

'Declare the object variable using WithEvents
Private WithEvents dlg As Form_DlgMyDialog

Private Sub cmdClose_Click()
    DoCmd.Close acForm, Me.Name
End Sub

Private Sub cmdSelect_Click()
    'Instantiate the dialog
    Set dlg = New Form_DlgMyDialog
    
    'Enable the appropriate combo
    dlg.WhichOne = Me.optMyOptionGroup
    
    'If we had declared dialog properties, we
    'could pass their values here:
    'dlg.Property1 = 123
    'dlg.Property2 = "some value"
    'etcâ¦
    
    'Show the dialog
    dlg.Visible = True
End Sub

Private Sub dlg_Finished(varReturn As Variant)
    Me.txtMyTextbox.Enabled = (Not IsNull(varReturn))
    
    If Not IsNull(varReturn) Then
        Me.txtMyTextbox = varReturn
    End If
End Sub

Private Sub Form_Unload(Cancel As Integer)
    'Clean up
    Set dlg = Nothing
End Sub

Noodude · November 26th, 2012, 11:55 AM

I found out when i was running into the error and fixed the problem. I had to add the option button to the option group in order for the form to correctly reference the buttons. Thanks to everyone who helped.

p.s.

I had to selected the option group and then click the add option button to make it add the button correctly.