ON KEY(n): Difference between revisions
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(Created page with "The ON KEY(n) statement defines a line number or label to go to (or a SUB to run) when a specified key is pressed. {{PageSyntax}} : ON KEY(n) GOSUB {{Parameter|linelabel}}|{{Parameter|linenumber}} : ON KEY(n) SUBprocedure {{PageDescription}} * Predefined and user defined KEY event number assignments to use with ON KEY(n): {{WhiteStart}} '''1 to 10'''.............Reserved '''F1 to F10''' function keys only. '''11, 12, 13 and 14'''...R...") |
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{{PageDescription}} | {{PageDescription}} | ||
* Predefined and user defined KEY event number assignments to use with ON KEY(n): | * Predefined and user defined KEY event number assignments to use with ON KEY(n): | ||
{{WhiteStart}} '''1 to 10'''.............Reserved '''F1 to F10''' function keys only. | {{WhiteStart}} '''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 | '''11, 12, 13 and 14'''...Reserved '''Up, Left, Right and Down''' numeric keypad arrows only | ||
| Line 20: | Line 20: | ||
{{PageExamples}} | {{PageExamples}} | ||
''Example 1:'' Using ON KEY with [[GOSUB]] to execute code. | ''Example 1:'' Using ON KEY with [[GOSUB]] to execute code. | ||
{{CodeStart}} | {{CodeStart}} | ||
{{Cl|KEY(n)|KEY(1) ON}} | {{Cl|KEY(n)|KEY(1) ON}} | ||
{{Cl|ON KEY(n)|ON KEY}}(1) {{Cl|GOSUB}} trap | {{Cl|ON KEY(n)|ON KEY}}(1) {{Cl|GOSUB}} trap | ||
| Line 29: | Line 29: | ||
{{Cl|PRINT}} "You pressed F1 like I told you to :)" | {{Cl|PRINT}} "You pressed F1 like I told you to :)" | ||
{{Cl|END}} | {{Cl|END}} | ||
{{Cl|RETURN}} | {{Cl|RETURN}} | ||
{{CodeEnd}} | {{CodeEnd}} | ||
''Example 2:'' Setting multiple ON KEY statements to send different values to a [[SUB]] procedure. | ''Example 2:'' Setting multiple ON KEY statements to send different values to a [[SUB]] procedure. | ||
{{CodeStart}} | {{CodeStart}} | ||
{{Cl|FOR...NEXT|FOR}} n = 1 {{Cl|TO}} 10 | {{Cl|FOR...NEXT|FOR}} n = 1 {{Cl|TO}} 10 | ||
{{Cl|KEY n|KEY}} n, {{Cl|STR$}}(n) ' assigns soft key as a numerical string | {{Cl|KEY n|KEY}} n, {{Cl|STR$}}(n) ' assigns soft key as a numerical string | ||
{{Cl|ON KEY(n)|ON KEY}}(n) Funct n 'designate SUB procedure and parameter value passed | {{Cl|ON KEY(n)|ON KEY}}(n) Funct n 'designate SUB procedure and parameter value passed | ||
{{Cl|KEY(n)|KEY}}(n) ON ' turns each key event monitor on | {{Cl|KEY(n)|KEY}}(n) ON ' turns each key event monitor on | ||
| Line 50: | Line 50: | ||
{{Cl|CLS}}' clears the screen and refreshes bottom soft key list | {{Cl|CLS}}' clears the screen and refreshes bottom soft key list | ||
{{Cl|PRINT}} "You pressed F"; {{Cl|LTRIM$}}({{Cl|STR$}}(num%)) | {{Cl|PRINT}} "You pressed F"; {{Cl|LTRIM$}}({{Cl|STR$}}(num%)) | ||
{{Cl|END SUB}} | {{Cl|END SUB}} | ||
{{CodeEnd}} | {{CodeEnd}} | ||
Revision as of 02:13, 23 January 2023
The ON KEY(n) statement defines a line number or label to go to (or a SUB to run) when a specified key is pressed.
Syntax
- ON KEY(n) GOSUB linelabel|linenumber
- ON KEY(n) SUBprocedure
Description
- Predefined and user defined KEY event number assignments to use with ON KEY(n):
Template:WhiteStart 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$(keyflag) + CHR$(scancode)
30 and 31...........Reserved F11 and F12 function keys only.
- See the KEY n page for user defined key or key combination presses and F function softkey assignments.
- GOSUB with a linelabel or linenumber or a SUB procedure (without the CALL keyword) can be triggered in QB64.
Examples
Example 1: Using ON KEY with GOSUB to execute code.
KEY(1) ON ON KEY(1) GOSUB trap PRINT "Press F1 to quit!" DO:LOOP 'never ending loop trap: PRINT "You pressed F1 like I told you to :)" END RETURN |
Example 2: Setting multiple ON KEY statements to send different values to a SUB procedure.
FOR n = 1 TO 10 KEY n, STR$(n) ' assigns soft key as a numerical string ON KEY(n) Funct n 'designate SUB procedure and parameter value passed KEY(n) ON ' turns each key event monitor on NEXT KEY ON 'displays F1 to F10 soft key assignments at bottom of screen DO LOOP UNTIL INKEY$ = CHR$(27) END SUB Funct (num%) CLS' clears the screen and refreshes bottom soft key list PRINT "You pressed F"; LTRIM$(STR$(num%)) END SUB |
See also