Q194201: BUG: ASCII 159 Appears With ! Text Box Format and Function Keys
Article: Q194201
Product(s): Microsoft FoxPro
Version(s): 5.0,5.0a,6.0,7.0
Operating System(s):
Keyword(s):
Last Modified: 12-NOV-2001
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The information in this article applies to:
- Microsoft Visual FoxPro for Windows, versions 5.0, 5.0a, 6.0, 7.0
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SYMPTOMS
========
If you use a text box control that has its Format property set to "!", when you
type a function key F2 through F9, F11, F12, or CTRL/SHIFT/ALT, or combinations
of these control keys, an ASCII 159 character appears in the text box. Depending
on the setting in the FontName property of the text box, the character may
appear as a Y with two dots over it, or some other character.
RESOLUTION
==========
Trap the keystrokes in the form or text box KeyPress event, and conditionally
issue a NODEFAULT if the keystroke is one that causes the ASCII 159 to appear.
Please see the MORE INFORMATION section of this article for details.
STATUS
======
Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article. We are researching this bug and will post new
information here in the Microsoft Knowledge Base as it becomes available.
MORE INFORMATION
================
Steps to Reproduce Behavior
---------------------------
1. Run the following code from a program (.prg) file:
PUBLIC oform1
oform1=CREATEOBJECT("form1")
oform1.SHOW
RETURN
DEFINE CLASS form1 AS FORM
AUTOCENTER = .T.
CAPTION = "KeyPress of Textbox"
NAME = "Form1"
ADD OBJECT text1 AS TEXTBOX WITH ;
FORMAT = "!", ;
HEIGHT = 24, ;
LEFT = 132, ;
TOP = 141, ;
WIDTH = 156, ;
NAME = "Text1"
ADD OBJECT command1 AS COMMANDBUTTON WITH ;
TOP = 7, ;
LEFT = 6, ;
HEIGHT = 27, ;
WIDTH = 197, ;
CAPTION = "Change TEXTBOX Format to !", ;
NAME = "Command1", ;
ENABLED = .F.
ADD OBJECT command2 AS COMMANDBUTTON WITH ;
TOP = 39, ;
LEFT = 6, ;
HEIGHT = 27, ;
WIDTH = 197, ;
CAPTION = "Blank TEXTBOX Format ", ;
NAME = "Command2"
ADD OBJECT text2 AS TEXTBOX WITH ;
CONTROLSOURCE = "thisform.text1.format", ;
HEIGHT = 23, ;
LEFT = 302, ;
READONLY = .T., ;
TABSTOP = .F., ;
TOP = 26, ;
WIDTH = 52, ;
NAME = "Text2"
ADD OBJECT label3 AS LABEL WITH ;
CAPTION = "text1.format:", ;
HEIGHT = 18, ;
LEFT = 219, ;
TOP = 28, ;
WIDTH = 70, ;
NAME = "Label3"
PROCEDURE INIT
CLEAR MACROS
ENDPROC
PROCEDURE command1.CLICK
WITH THISFORM.text1
.FORMAT = "!"
.SETFOCUS()
.VALUE = ''
.PARENT.REFRESH()
ENDWITH
THIS.ENABLED = .F.
THISFORM.command2.ENABLED = .T.
ENDPROC
PROCEDURE command2.CLICK
WITH THISFORM.text1
.FORMAT = ""
.SETFOCUS()
.VALUE = ''
.PARENT.REFRESH()
ENDWITH
THIS.ENABLED = .F.
THISFORM.command1.ENABLED = .T.
ENDPROC
ENDDEFINE
2. Press a function key, F2 through F9, F11 or F12.
An ASCII 159 character appears in the text box. It may look like a Y with two
dots over it.
As a workaround, you can intercept the keystrokes in the KeyPress Event of the
form or text box.
Demonstration of Workaround Using Text Box KeyPress
---------------------------------------------------
This workaround encapsulates the code necessary in the text box, but you need to
apply it to each text box that exhibits the behavior. You can place the code in
your base text box class if you want.
1. Modify the preceding program, and add the following procedure just before the
ENDDEFINE line:
PROCEDURE text1.KEYPRESS
LPARAMETERS nKeyCode, nShiftAltCtrl
LOCAL lcSetComp, lnLastKey
IF '!' $ THIS.FORMAT
lcSetComp = SET("Compatible")
SET COMPATIBLE ON
lnLastKey = LASTKEY()
SET COMPATIBLE &lcSetComp
* If a function key is pressed, do not process it.
* We differentiate between F keys and normal keys
* by looking at LASTKEY() value, which is only unique
* with SET COMPATIBLE ON. With SET COMPATIBLE ON, F2
* through F10 are < 0 regardless of Shift, Alt, or Ctrl
* modifier. F10 through F12 are between 133 and 140.
IF lnlastkey < 0 OR ;
BETWEEN(lnlastkey, 133, 140)
NODEFAULT
ENDIF
ENDIF
ENDPROC
2. Rerun the program, press a function key F2 through F9, F11 or F12.
The ASCII 159 character does not appear.
Demonstration of Workaround Using Form KeyPress
-----------------------------------------------
This workaround places the code necessary in the form KeyPress, and requires you
to set the KeyPreview property of form to .T. as well.
1. Modify the preceding program, and add the following code after the line 'NAME
= "Form1"':
KEYPREVIEW = .T.
2. Add the following procedure just before the ENDDEFINE line:
PROCEDURE KEYPRESS
LPARAMETERS nKeyCode, nShiftAltCtrl
LOCAL lcSetComp, lnLastKey
* Check to see if activecontrol is a text box with ! in format.
IF THISFORM.ACTIVECONTROL.BASECLASS = 'Textbox' AND ;
'!' $ THISFORM.ACTIVECONTROL.FORMAT
lcSetComp = SET("Compatible")
SET COMPATIBLE ON
lnLastKey = LASTKEY()
SET COMPATIBLE &lcSetComp
* If a function key is pressed, do not process it.
* We differentiate between F keys and normal keys
* by looking at LASTKEY() value, which is only unique
* with SET COMPATIBLE ON. With SET COMPATIBLE ON, F2
* through F10 are < 0 regardless of Shift, Alt, or Ctrl
* modifier. F10 through F12 are between 133 and 140.
IF lnlastkey < 0 OR ;
BETWEEN(lnlastkey, 133, 140)
NODEFAULT
ENDIF
ENDIF
ENDPROC
3. Rerun the program, press a function key F2 through F9, F11 or F12.
The ASCII 159 character does not appear.
REFERENCES
==========
(c) Microsoft Corporation 1998, All Rights Reserved.
Contributions by Jim Saunders, Microsoft Corporation
Additional query words: kbVFp300bbug kbVFp500abug kbVFp600bug kbContainer kbCtrl
======================================================================
Keywords :
Technology : kbVFPsearch kbAudDeveloper kbVFP500 kbVFP600 kbVFP700 kbVFP500a
Version : :5.0,5.0a,6.0,7.0
Issue type : kbbug
Solution Type : kbnofix
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