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Chapter 14. Statement Reference
238
Syntax:
KEY (keynumber){ON|OFF}
Parameter:
keynumber
A numeric expression which returns a value from 1 to 31, 33 to 38, and 501
to 550.
Description:
■
KEY ON
KEY
ON
enables keystroke trapping for a function key specified by
keynumber
.
(Refer to Appendix E, "Key Number Assignment on the Keyboard.")
• Between every execution of statements, the Interpreter checks whether a function
key specified by the
KEY
ON
statement is pressed or not. If the key is pressed,
the Interpreter transfers control to the event-handling routine defined by an
ON
KEY
...
GOSUB
statement (which should be executed before the
KEY
ON
state-
ment).
• If a function key which has been assigned a null string by the
KEY
statement is
specified by the
KEY
ON
statement, the keystroke trap takes place.
• If you specify a function key which has been defined as a backlight function on/off
key, trigger switch, shift key, or software keyboard display key by using the
KEY
ON
statement, then no keystroke trap takes place.
• Keystroke trapping has priority over the
INKEY$
function.
• When a program waits for the keyboard entry by the
INPUT
,
LINE
INPUT
state-
ment or
INPUT$
function, pressing a function key specified by the
KEY
ON
state-
ment neither reads the pressed key data nor causes keystroke trapping.
• Specifying 32 to
keynumber
will be ignored.
■
KEY OFF
KEY
OFF
disables keystroke trapping for a function key specified by
keynumber
.
• Specifying 32 to
keynumber
will be ignored.
I/O statement
KEY ON and KEY OFF
Enables or disables keystroke trapping for a specified function key.
Содержание BHT-BASIC 100 SERIES
Страница 1: ......
Страница 161: ...153 Chapter 10 Sleep Function CONTENTS 10 1 Sleep Function 154...
Страница 163: ...155 Chapter 11 Resume Function CONTENTS 11 1 Resume Function 156...
Страница 173: ...165 Chapter 13 Backlight Function CONTENTS 13 1 Backlight Function 166...
Страница 192: ...Chapter 14 Statement Reference 184 Example OPEN master Dat AS 1 FIELD 1 20 AS bar 10 AS ky CLFILE 1 CLOSE 1...
Страница 249: ...241 Example CLOSE IF kyIn Y THEN KILL Master Dat END IF Reference Statements CLFILE...
Страница 349: ...341 Run time errors Error code Meaning 05h Parameter out of the range checktype is out of the range...
Страница 383: ...375 Run time errors Reference Error code Meaning 05h Parameter out of the range Functions LEFT LEN and RIGHT...