Q132178: PRB: DO FORM Does Not Display a Form

Article: Q132178
Product(s): Microsoft FoxPro
Version(s): WINDOWS:3.0
Operating System(s): 
Keyword(s): 
Last Modified: 15-FEB-2000

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The information in this article applies to:

- Microsoft Visual FoxPro for Windows, version 3.0 
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SYMPTOMS
========

When a DO FORM command is issued, the form is not displayed. The form is never
displayed, and no instance variable is created.

CAUSE
=====

When a form created with the Form Designer is run, the instance is not created
under the following circumstances:

- The Init of the Form returns false (.F.).

-or-

- One of the object members of the form is not instantiated.

With the Visual FoxPro object model, all objects contained in a form are created
before the form is instantiated. The form is created if its contained members
have been successfully created. In particular, the Init event of the form is
triggered after the Init of all the controls it contains. If the method
associated with the Init event of any control in the form returns false (.F.),
the object member is not created and the form in turn is not instantiated. If
the object member is not created, the Init of the form is not run, so the form
is not created.

WORKAROUND
==========

Ensure that all object members of a form are created before the form is
instantiated. For example, ensure that no Init method of a control returns false
(.F.) if you want to be able to create a form. You can use the Visible and
Enabled properties of a control to monitor its visibility and accessibility.

STATUS
======

This behavior is by design.

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

Steps to Reproduce Behavior
---------------------------

1. Create a form.

2. Select the CommandButton control from the Form controls toolbar, and place a
  command button on the form.

3. In the property sheet, ensure that the Object is Command1, and select the
  method for the Init event. Type the following:

  " Return cReturn " (without the quotation marks)

4. Save the form.

5. In the Command window, type "cReturn= .t" (without the quotation marks).

6. Run the form. The form is displayed.

7. In the Command window, type

     CLEAR ALL
     cReturn = .f.

8. Run the form. because the command button is not created, the form is not
  created.

Additional query words: VFoxWin

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Keywords          :  
Technology        : kbVFPsearch kbAudDeveloper kbVFP300
Version           : WINDOWS:3.0

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