Q140296: How to Use a KeyPress Event in Lieu of ON KEY LABEL
Article: Q140296
Product(s): Microsoft FoxPro
Version(s): 3.00
Operating System(s):
Keyword(s): kbcode
Last Modified: 17-AUG-1999
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The information in this article applies to:
- Microsoft Visual FoxPro for Windows, version 3.0
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SUMMARY
=======
Many developers use ON KEY LABEL to assign programs or procedures within
programs that are to be executed upon pressing a specific key (usually a
function key). However, if the ON KEY LABEL assignment is to be specific to a
control within a form, a better alternative would be to use the KeyPress event
of that control.
MORE INFORMATION
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The KeyPress event is available for the following form controls:
CheckBox, ComboBox, CommandButton, EditBox, Form, ListBox, OptionButton,
Spinner, TextBox
It is possible to use this event to check for the press of a specific key. When
using the KeyPress event to perform an action based on a function key, the
function key's value should be used as shown in this table:
Key Alone Shift Ctrl Alt
------------------------------------
F1 28 84 94 104
F2 -1 85 95 105
F3 -2 86 96 106
F4 -3 87 97 107
F5 -4 88 98 108
F6 -5 89 99 109
F7 -6 90 100 110
F8 -7 91 101 111
F9 -8 92 102 112
F10 -9 93 103 113
F11 133 135 137 139
F12 134 136 138 140
For more information on key values, refer to the INKEY() function in Visual
FoxPro Help file.
Step-by-Step Example
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The following steps show how to use the KeyPress event.
1. Create a form, and place a text box on it.
2. In the ControlSource property of the text box, type mykey (or any other
variable that you might prefer).
3. Place the following code in the KeyPress event of the text box:
LPARAMETERS nKeyCode, nShiftAltCtrl
*: The previous line of code is already contained in the KeyPress event
*: by default.
DO CASE
CASE nKeyCode = 28
WAIT WINDOW "The F1 Key has been pressed" NOWAIT
mykey = "F1 Key"
ThisForm.Refresh
CASE nKeyCode = -4
WAIT WINDOW "The F5 Key has been pressed" NOWAIT
mykey = "F5 Key"
ThisForm.Refresh
ENDCASE
4. Place the following code in the Load event of the form:
CLEAR MACROS
SET HELP OFF
*: This will disable FoxPro's default function key assignments.
5. Place the following code in the Destroy event of the form:
RESTORE MACROS
SET HELP ON
*: This will restore FoxPro's default function key assignments.
6. Place a command button on the form, and place the following code in its click
event:
ThisForm.Release
7. Save and run the form. If either the F1 or F5 key is pressed, the appropriate
WAIT WINDOW messages should appear, and the text box should be updated.
Additional query words: VFoxWin
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Keywords : kbcode
Technology : kbVFPsearch kbAudDeveloper kbVFP300
Version : 3.00
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