KnowledgeBase Archive

An Archive of Early Microsoft KnowledgeBase Articles

View on GitHub

Q192273: PRB: SendKeys Does Not Work with NumLock or Caplock

Article: Q192273
Product(s): Microsoft Visual Basic for Windows
Version(s): WINDOWS:4.0,5.0,6.0
Operating System(s): 
Keyword(s): kbcode kbnokeyword kbVBp400 kbVBp500 kbVBp600 kbGrpDSVB
Last Modified: 11-JAN-2001

-------------------------------------------------------------------------------
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 
-------------------------------------------------------------------------------

SYMPTOMS
========

Using SendKeys to change the state of {CAPSLOCK} or {NUMLOCK} is not effective.

CAUSE
=====

Toggling {CAPSLOCK} or {NUMLOCK} with the SendKeys statement is only in effect
for the continuous subsequent keys sent by SendKeys. The state of {CAPSLOCK} or
{NUMLOCK} is reset when Visual Basic yields to other processes. For example,
this occurs when the SendKeys statement's Wait parameter is set to "True", or
when a DoEvents statement is executed.

RESOLUTION
==========

Use SendKeys to toggle {CAPSLOCK} or {NUMLOCK} only when sending a series of
keys continuously in a single or multiple number of SendKeys statements. To
toggle the {CAPSLOCK} or {NUMLOCK} permanently:

1. Use the KeyState control that comes with Visual Basic 4.0.

  - or -

2. Use the Win32 API. See the article in the References section for details.

STATUS
======

This behavior is by design.

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

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

1. Start a new Standard EXE project. From1 is created by default.

2. Add a TextBox to Form1 and paste the following code in the code Window:

      Private Sub Text1_Click()
          SendKeys "s"
          SendKeys "{CAPSLOCK}"  ' Turn on the CapsLock
          SendKeys "o"  ' will be printed in caps
          For i = 0 To 10
          SendKeys Chr(Asc("a") + i)  'will be printed in caps
          Next
          'DoEvents  ' uncommenting this will print next line in smalls
          SendKeys "o"  ' will be printed in caps
          SendKeys "{CAPSLOCK}"  ' Turn off the caps lock
          SendKeys "o"  ' Will be printed in smalls
      End Sub

3. Turn off the Caps Lock. Run the project. Note that the SendKeys work as
  expected.

4. Un-comment the DoEvents statement. Run the project. The Caps Lock is reset
  after the DoEvents call.

5. In any SendKeys statement after SendKeys "{CAPSLOCK}", pass "True" as the
  second parameter. The state of Caps Lock is reset after that statement.

REFERENCES
==========

For additional information, please see the following article in the Microsoft
Knowledge Base:

  Q177674 : HOWTO: Toggle the NUM LOCK, CAPS LOCK, and SCROLL LOCK Keys

======================================================================
Keywords          : kbcode kbnokeyword kbVBp400 kbVBp500 kbVBp600 kbGrpDSVB 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB500Search kbVB600Search kbVBA500 kbVBA600 kbVB500 kbVB600 kbVB400Search kbVB400
Version           : WINDOWS:4.0,5.0,6.0
Issue type        : kbprb

=============================================================================

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.