Converts a string representation of a handle
to a valid handle.
Syntax
Caution:
Use this function only to
convert a handle previously stored as a string value back to a valid
handle. If you convert an arbitrary string to handle using this
function and then reference the new handle, a system error will
occur. If you use the VALID-HANDLE function to validate a handle
generated from an arbitrary string value, a system error will occur.
-
handle-string
- A string representation of a handle. Since handles are integer
values, the string must contain only numeric characters.
Example
The
following procedure creates a frame, stores the handle of the frame
as a string value, deletes the frame, converts the string representation
of the frame handle back to a valid handle, and then tests if the
handle is valid:
r-widhd.p
DEFINE VARIABLE whand AS HANDLE NO-UNDO.
DEFINE VARIABLE chand AS CHARACTER NO-UNDO.
CREATE FRAME whand.
chand = STRING(whand).
DELETE WIDGET whand.
whand = HANDLE(chand).
MESSAGE VALID-HANDLE(whand) VIEW-AS ALERT-BOX INFORMATION BUTTONS OK.
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The VALID-HANDLE function returns a FALSE value
because the frame was deleted and the handle is no longer valid.
Notes
- The
HANDLE function can convert the string representation of procedure,
system, and widget handles.
- For SpeedScript, the only valid use is to convert the handle
of a QUERY object that you create using the CREATE WIDGET statement.
