mirror of
https://github.com/QB64Official/qb64.git
synced 2024-07-16 18:55:13 +00:00
77 lines
2.1 KiB
Markdown
77 lines
2.1 KiB
Markdown
|
**KEY(n)** assigns, enables, disables or suspends event trapping of a keypress by setting the flag [ON](ON), [STOP](STOP) or [OFF](OFF).
|
||
|
|
|
||
|
|
## Syntax
|
||
|
|
|
||
|
|
> KEY(number) {[ON](ON) | [OFF](OFF) | [STOP](STOP)}
|
||
|
|
|
||
|
|
## Description
|
||
|
|
|
||
|
|
* Predefined and user defined KEY event number assignments to use with KEY(n):
|
||
|
|
|
||
|
|
```text
|
||
|
|
|
||
|
|
**1 to 10**.............Reserved **F1 to F10** function keys only.
|
||
|
|
**11, 12, 13 and 14**...Reserved **Up, Left, Right and Down** numeric keypad arrows only
|
||
|
|
**15 to 29**............**user-defined keys** using value: [CHR$](CHR$)(keyflag) + [CHR$](CHR$)([Keyboard scancodes](Keyboard-scancodes))
|
||
|
|
**30 and 31**...........Reserved **F11 and F12** function keys only.
|
||
|
|
|
||
|
|
```
|
||
|
|
|
||
|
|
* Keypresses can be read during [INKEY$](INKEY$), [INPUT$](INPUT$) or [INPUT](INPUT) procedures without losing the input.
|
||
|
|
* Key event reads will also interrupt [SLEEP](SLEEP).
|
||
|
|
* [KEY(n)](KEY(n)) specific status modes are:
|
||
|
|
- **ON** enables specific keypress events to be monitored.
|
||
|
|
- **STOP** suspends specific keypress reads, but remembers them. When re-enabled the key presses will be returned.
|
||
|
|
- **OFF** disables specified keypress reads and will not remember the event.
|
||
|
|
|
||
|
|
## Example(s)
|
||
|
|
|
||
|
|
How to trap the LEFT direction keys on both the dedicated cursor keypad and the numeric keypad.
|
||
|
|
|
||
|
|
```vb
|
||
|
|
|
||
|
|
KEY 15, CHR$(128) + CHR$(75) ' Assign trap for LEFT arrow key on the cursor keypad
|
||
|
|
ON KEY(15) GOSUB CursorPad
|
||
|
|
KEY(15) ON ' enable event trapping
|
||
|
|
|
||
|
|
ON KEY(12) GOSUB NumericPad ' Trap LEFT key on number pad
|
||
|
|
KEY(12) ON ' enable event trapping
|
||
|
|
|
||
|
|
DO
|
||
|
|
LOOP UNTIL UCASE$(INKEY$) = "Q" ' Idle loop for demo
|
||
|
|
SYSTEM
|
||
|
|
|
||
|
|
CursorPad:
|
||
|
|
PRINT "Pressed LEFT key on cursor keypad."
|
||
|
|
RETURN
|
||
|
|
|
||
|
|
NumericPad:
|
||
|
|
PRINT "Pressed LEFT key on numeric keypad."
|
||
|
|
RETURN
|
||
|
|
|
||
|
|
```
|
||
|
|
|
||
|
|
Trapping the F5 keypress.
|
||
|
|
|
||
|
|
```vb
|
||
|
|
|
||
|
|
KEY(5) ON
|
||
|
|
ON KEY(5) GOSUB execute
|
||
|
|
PRINT "Press F5 (or ESC) to quit!)"
|
||
|
|
DO
|
||
|
|
LOOP UNTIL INKEY$ = CHR$(27) ' idle loop
|
||
|
|
SYSTEM
|
||
|
|
execute:
|
||
|
|
PRINT "You pressed the F5 key..."
|
||
|
|
SLEEP 1
|
||
|
|
PRINT "Press any key to continue..."
|
||
|
|
SLEEP
|
||
|
|
|
||
|
|
```
|
||
|
|
|
||
|
|
## See Also
|
||
|
|
|
||
|
|
* [ON KEY(n)](ON-KEY(n)), [KEY n](KEY-n) (softkeys)
|
||
|
|
* [_KEYHIT](_KEYHIT), [_KEYDOWN](_KEYDOWN)
|
||
|
|
* [Keyboard scancodes](Keyboard-scancodes)
|