Q143311: INFO: Form Events and Sub Procedures Can Be Exposed

Article: Q143311
Product(s): Microsoft Visual Basic for Windows
Version(s): 4.0,5.0,6.0
Operating System(s): 
Keyword(s): kbGrpDSVB
Last Modified: 11-JAN-2001

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The information in this article applies to:

- Microsoft Visual Basic Learning Edition for Windows, versions 5.0, 6.0 
- Microsoft Visual Basic Professional Edition for Windows, versions 5.0, 6.0 
- Microsoft Visual Basic Enterprise Edition for Windows, versions 5.0, 6.0 
- Microsoft Visual Basic Standard Edition, 32-bit, for Windows, version 4.0 
- Microsoft Visual Basic Professional Edition, 16-bit, for Windows, version 4.0 
- Microsoft Visual Basic Professional Edition, 32-bit, for Windows, version 4.0 
- Microsoft Visual Basic Enterprise Edition, 16-bit, for Windows, version 4.0 
- Microsoft Visual Basic Enterprise Edition, 32-bit, for Windows, version 4.0 
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SUMMARY
=======

Starting with Visual Basic 4.0, forms are public. Therefore, the form events and
sub procedures are prefaced by the private keyword so they are not publicly
visible members of the form.

MORE INFORMATION
================

In Visual Basic 3.0, a form's events and sub procedures were private to the
form, and could not be accessed outside of the form's scope. Because a form is
public in Visual Basic 4.0 and higher, its events and sub procedures can be
exposed by either prefacing it with Public or by removing Private from the
event.

Step-by-Step Example
--------------------

The following example works in Visual Basic 4.0 and higher but not in Visual
Basic 3.0. To create the program, do the following:

1. Start Visual Basic or from the File menu, choose New Project (ALT, F, N) if
  Visual Basic is already running. Form1 is created by default.

2. In Form1 enter the following code:

        Sub DispMsg ()
            MsgBox "Inside Sub"
        End Sub

3. Add a module to the project and in Module1 enter the following code:

        Sub main()
           'some other code stuff could go here
           Call Form1.DispMsg
        End Sub

4. For VB4, select the Tools, Options menu item and the Project tab. Set Startup
  Form to Sub Main.

5. For VB5/6: Select the Project, Properties menu item and the General tab. Set
  the Startup Object to Sub Main.

6. Run this program. The Module1 Main sub procedure calls the DispMsg sub
  procedure in the form.

  NOTE: Invoking an event through code is not good programming practice.
  However, you can get at routines and form events if needed. Just ensure that
  they are visible members of the class (the form in this case).

Additional query words: kbVBp400 kbVBp500 kbVBp600 kbVBp kbdsd kbDSupport KbVBA kbControl

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Keywords          : kbGrpDSVB 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB500Search kbVB600Search kbVBA500 kbVBA600 kbVB500 kbVB600 kbVB400Search kbVB400 kbVB16bitSearch
Version           : :4.0,5.0,6.0
Issue type        : kbinfo

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