_BUTTONCHANGE

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The _BUTTONCHANGE function returns -1 or 1 when a specified button number on a controller device has been pressed or released.


Syntax

press% = _BUTTONCHANGE(button_number%)


Description

  • Values returned are -1 for a press and 1 when a button is released. No press or release event returns zero.
  • The button_number% must be a number which does not exceed the number of buttons found by the _LASTBUTTON function.
  • The number of _DEVICES must be read before using _DEVICE$, _DEVICEINPUT or _LASTBUTTON.
  • Note: The center mouse button is button number 2. Center can also be read using _MOUSEBUTTON(3).


Examples

Example: Reading multiple controller device buttons, axis and wheels.

FOR i = 1 TO _DEVICES PRINT STR$(i) + ") " + _DEVICE$(i) + " Buttons:"; _LASTBUTTON(i); ",Axis:"; _LASTAXIS(i); ",Wheel:"; _LASTWHEEL(i) NEXT DO d& = _DEVICEINPUT IF d& THEN ' the device number cannot be zero! PRINT "Found"; d&; FOR b = 1 TO _LASTBUTTON(d&) PRINT _BUTTONCHANGE(b); _BUTTON(b); NEXT FOR a = 1 TO _LASTAXIS(d&) PRINT _AXIS(a); NEXT FOR w = 1 TO _LASTWHEEL(d&) PRINT _WHEEL(w); NEXT PRINT END IF LOOP UNTIL INKEY$ = CHR$(27) 'escape key exit END

Note: When there is no device control to read, a FOR n = 1 TO 0 loop will not run thus avoiding a control function read error.


See also



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