Destructor
event (DataWindows)
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
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.
See also