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

• Microsoft Visual FoxPro for Windows, version 3.0

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.

WORKAROUND

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.

  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 for 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 list box
   * 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