Q32272: All Event Handling Is Disabled in an ON ERROR GOTO Handler

Article: Q32272
Product(s): See article
Version(s): 2.00 2.01 3.00 4.00 4.00b 4.50
Operating System(s): MS-DOS
Keyword(s): ENDUSER | B_BasicCom | mspl13_basic
Last Modified: 21-DEC-1989

The following information applies to QuickBASIC Versions 2.00, 2.01,
3.00, 4.00, 4.00b and 4.50, to Microsoft BASIC Compiler Versions 6.00
and 6.00b for MS-DOS and MS OS/2, and to Microsoft BASIC PDS Version
7.00 for MS-DOS and MS OS/2.

All event handling is suspended in an ON ERROR GOTO handler. The
following types of events are suspended during an error trapping
routine:

1. Key trapping (ON KEY(n) GOSUB)

2. Timer (ON TIMER(n) GOSUB)

3. Communications (ON COM(n) GOSUB)

4. Light Pen (ON PEN GOSUB)

5. Joy Sticks (ON STICK GOSUB)

6. User-defined events (ON UEVENT GOSUB); not available in QuickBASIC
   versions prior to Version 4.00b and Microsoft BASIC Compiler
   versions prior to Version 6.00.

The events are enabled again as soon as the error trap is exited with
the RESUME or RESUME NEXT statement.

The following is a code example:

   ON ERROR GOTO trap
   ON KEY(1) GOSUB keytrap
   KEY (1) ON
   ERROR 5    ' Forces an error 5.
   END

   trap:
     PRINT "In the error trap, enter F1"
     while inkey$=""
     wend
     RESUME NEXT

   keytrap:
     Print "A key as pressed"
     return

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