Visual Basic Combo Control Receives Extra "Click" Event

Last reviewed: November 23, 1994
Article ID: Q82255

The information in this article applies to:

Microsoft Windows operating system versions 3.1, 3.11

SUMMARY

When you run Visual Basic in Microsoft Windows version 3.1, double-clicking an item listed in a simple Combo control generates the following events:

   Combo(x)_Click
   Combo(x)_Click
   Combo(x)_DblClick

However, in Windows 3.0, the events that were generated through the same action were:

   Combo(x)_Click
   Combo(x)_DblClick

This means an extra mouse-button click event is processed and can cause unexpected results.

MORE INFORMATION

This is a case where Visual Basic 1.0 is relying on the order in which messages are processed. Visual Basic was designed to use the message order that Windows 3.0 provides. Because Windows 3.1 uses an extended message order to process a "click" event, there is an extra occurrence if the application is dependent upon message order.

This is not a design problem in Windows 3.1 because Windows is sending the correct messages. Visual Basic is just "expecting" the messages to come in a specific order.

KBCategory: kbother kbinterop kbprg
KBSubcategory: Win31
Additional reference words: 3.10 visual basic events click double
3.11

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: November 23, 1994
© 1998 Microsoft Corporation. All rights reserved. Terms of Use.