GPF Error

[Joe Speroni]

Ive been chasing a GPF error for over a week. Finally with
Lance's help I was able to isloate the problem in my code. Lest
others travel this path, I document the problem here. I'd also
suggest the PB DLL manual consider a warning to help future
users.

Basically the sin to be avoided is

CONTROLS SHALL NOT COMMIT SUICIDE

or,

Thou shall not CONTROL KILL yourself from
within a CallBack function.

My code had the equivalent of:

CASE %WM_COMMAND
SELECT CASE LOWRD(CBWPARAM)
CASE 111
KILL hDlg,111

The code never failed, if only a mouse clicks were used.
Activation via ALT+Letter caused intermittent GPF's, depending
of the size and timing of execution of apparently unrelated code.

I learned that DIALOG END hDlg from the current Dialog is also
to be avoided, for the same reason.

[Lance Edmonds]

I agree about the "suicide" issue, but...

I learned that DIALOG END hDlg from the current Dialog is also to be avoided, for the same reason.

Sorry Joe, but this statement is not very accurate... I use this technique all the time.

In general terms, windows ignores some (API) functions if used during processing of certain messages... for example, DIALOG END should not be performed during processing %WM_INITDIALOG.


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Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>