Q127005: PRB: UP/DOWN Arrow Keys Call Click Event in Form

Article: Q127005
Product(s): Microsoft FoxPro
Version(s): 3.0
Operating System(s): 
Keyword(s): 
Last Modified: 05-JUN-2002

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The information in this article applies to:

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

Pressing the UP or DOWN arrow in a list box triggers the Click event.

CAUSE
=====

This behavior is by design. When the arrow keys are pressed to navigate through
a list, the value associated with the list is modified. This triggers the Click
event.

RESOLUTION
==========

If you do not want to execute the code in the Click event handler, you can
verify the value of the last keypress when the Click event is triggered. If the
LASTKEY() function returns the value of the UP or DOWN arrow keys, issue a
RETURN in your routine.

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

The Click event handler routine is also executed in the following scenarios:

- When the Spacebar is pressed on a command button, check box, or option
  button.

- When the Enter key is pressed on a command button, check box, text box, or
  option button.

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

The following code will demonstrate that the Click event is triggered when the UP
or DOWN arrows are pressed in a list box. It also illustrates the alternative of
verifying the value of the last key pressed.

     ofrm1 = CREATEOBJECT('frm1')
     ofrm1.show
     READ EVENTS

     ***********************
     ** Class definitions **
     ***********************

     DEFINE CLASS frm1 AS form
        ScaleMode=3
        ADD OBJECT lsttest AS lstclick
        ADD OBJECT cmdtest AS cmdquit
        Caption = "Press the Up and Down Arrow keys"
     ENDDEFINE

     DEFINE CLASS lstclick AS listbox
     * Defines a list with hard coded values

        RowSourceType = 1    && Value
        RowSource = "1,2,3"  && List of numbers to be displayed
        Height = 85
        Left = 84
        Top = 60

        PROCEDURE Click
        IF LASTKEY()= 5  OR LASTKEY()=24 &&Traps for the Up or Down arrow
          RETURN .T.
        ELSE
          WAIT WINDOW "Click has been pressed in the list box"
        ENDIF
        ENDPROC
     ENDDEFINE

     * Define a Quit command button that releases the form
     DEFINE CLASS cmdquit AS Commandbutton
        Top=150
        Left=84
        Caption= "Quit"

        PROCEDURE click
        RELEASE Thisform
        CLEAR EVENTS
        ENDPROC
     ENDDEFINE


Additional query words: VFoxWin

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Keywords          :  
Technology        : kbVFPsearch kbAudDeveloper kbVFP300
Version           : :3.0
Issue type        : kbprb

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