PRB: Return 0 in TextBox Valid Allows Switching Active Form

Last reviewed: January 8, 1997
Article ID: Q161864
The information in this article applies to:
  • Microsoft Visual FoxPro for Windows, versions 3.0, 3.0b, 5.0

SYMPTOMS

The Help for Visual FoxPro states the following about the Valid event of a control:

   If 0 is returned, the control does not lose focus.

This is true if you try to move between controls on a single form. But if a control returns 0 in the Valid event, you will be able to move the focus to a different form.

RESOLUTION

To prevent the control from losing focus, you should return .F. (False) from the Valid event of the control:

   RETURN .F.

To disable the "Invalid Input" message that a False (.F.) return value causes, issue the following command:

  SET NOTIFY OFF

This should be done at the start of an application or in the Init event of a form.

STATUS

Microsoft is researching this behavior and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

Steps to Reproduce Behavior

  1. Create a form called AAA.

  2. Add two text boxes to the form.

  3. In the Valid of Text1 add the following code:

           IF EMPTY(This.Value)
    
             RETURN 0
           ENDIF
    
    

  4. Save the form.

  5. Create a form called BBB, and add a text box control to it.

  6. Save and run form BBB.

  7. Run form AAA.

  8. Try to Tab from the first text box to the second text box on form AAA. Then click on form BBB.

You will not be able to move from Text1 to Text2 on form AAA as long as Text1 is empty. But you will be able to click on form BBB and make it the active form.


KBCategory: kbui kbprb
KBSubcategory: FxtoolFormdes
Additional reference words: 3.00 3.00b 5.00 vfoxwin kbdsd



THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.

Last reviewed: January 8, 1997
© 1998 Microsoft Corporation. All rights reserved. Terms of Use.