UEVENT Statements

 Action

 Enable, disable, or suspend a user-defined event.

 Syntax


  UEVENT ON

  UEVENT OFF

  UEVENT STOP


 Remarks

 The effects of the  UEVENT statements are like those of other event-trapping
 statements (such as  COM or  KEY). When  UEVENT  ON is executed, the
 event-trapping routine is enabled. Occurrences of the event trigger
 execution of the event-handling routine.

 When  UEVENT OFF is executed, the event-trapping routine is disabled. Any
 occurrences of the event are ignored.

 When  UEVENT STOP is executed, the event-trapping routine is suspended. An
 event occurrence is remembered, and the event-trapping routine performed as
 soon as a  UEVENT ON statement is executed.

 When a user-defined event trap occurs (that is, the  GOSUB is performed), an
 automatic  UEVENT STOP is executed so that recursive traps cannot take
 place. The  RETURN operation from the trapping subroutine automatically
 performs a  UEVENT ON statement unless an explicit  UEVENT OFF was performed
 inside the subroutine.

 See Also

  ON  event,  SetUEvent

 Example

 The following example shows a primitive use of the  ON UEVENT statement.

 PRINT "Entering an odd number causes a UEVENT to occur."
 ON UEVENT GOSUB Event1
 UEVENT ON
 DO
     PRINT "Enter a number --> ";
     N = VAL(INPUT$(1)). PRINT N. PRINT
     SELECT CASE N
         CASE 1, 3, 5, 7, 9
             CALL SetUevent    'Odd number was entered, causing UEVENT.
         CASE ELSE
             PRINT "No UEVENT occurred.". PRINT
     END SELECT
     LoopCount = LoopCount + 1
 LOOP UNTIL LoopCount = 10

 Event1.
     PRINT "Now processing the UEVENT. The odd number was"; N
     RETURN