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ON TIMER Trap for Elapsed Time
ON TIMER(n) GOSUB {linenum | linelabel}
Establishes a subroutine to which QuickBASIC will branch if a
specified number of seconds have passed. The trap must also be turned
on by means of a TIMER ON statement.
n A numeric expression in the range 1 to 86,400 (1 second to
24 hours).
linenum The first line of a timer-handling subroutine. Setting
linenum to 0 disables trapping.
linelabel A label identifying the first line of a timer-handling
routine.
-----------------------------------------------------------------------
Notes: {linenum | linelabel} must be defined at the main program
level.
With trapping in effect, QuickBASIC checks to see if the
specified number of seconds have elapsed. When the
specified amount of time has passed, QuickBASIC branches
to the specified subroutine and temporarily suspends
trapping (by means of an implicit TIMER STOP statement).
Trapping automatically resumes when a RETURN from the
handling subroutine is executed (unless the handler
explicitly performs a TIMER OFF or TIMER STOP).
All event trapping is temporarily disabled when QuickBASIC
is executing an error-handling routine (established via an
ON ERROR statement).
If the "Checking Between Statements" option is in effect,
QB checks after each statement. If the "Event Trapping"
option is selected, QB checks after each new program line.
If neither option is selected, no trapping takes place.
For command-line compilation, /v enables checking after
each statement, and /w enables checking after each new
line. If neither switch is used, no trapping takes place.
See Also:
TIMER (Statement)
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