Destructor event
Description
Occurs when the DataWindow control or DataStore object is
destroyed, immediately after the Close event of a window or form.
PowerBuilder event information
Event ID: pbm_destructor
Web ActiveX event information
Event name: onDestructor
Return Values
There are no special outcomes for this event. The only code
is:
-
0 Continue processing
Usage
The Destructor event destroys the DataWindow control or DataStore
object and removes it from memory. After it has been destroyed,
you can no longer refer to it in other event code. (If you do, a
runtime error occurs.)
Restriction on methods
Calling a DataStore method that accesses the underlying DataStore
internals within this event is not a valid coding practice and can
fail silently. Such methods include RowCount, DBCancel,
and Modify.
When you issue a DESTROY on a DataStore,
the Destructor event is triggered and a Windows WM_DESTROY
message is added to the object’s message queue. WM_DESTROY
invalidates the memory for the DataStore. If the WM_DESTROY
message is handled before the method calls in the Destructor event,
methods that attempt to access the destroyed memory fail silently.