From: Nelson Nieves (Nelson@cybernetworking.com)
Subject: DriveComboBox and Error 21
Newsgroups: borland.public.delphi.vcl.components.using
Date: 1998/02/06


I am trying to figure out how to trap error 21 when selecting a floppy
drive from a DriveComboBox control when there is no diskette in the drive.

I have tried entering code in the OnChange Event of the DriveComboBox
control with no result.

I used to trap this same error in Visual Basic by using the DriveComboBox's
OnChange event handler.

Please help me with this frustrating error.

Any help appreciated.

Nelson Nieves

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From: Peter Below (100113.1101@compuserve.com)
Subject: Re: DriveComboBox and Error 21
Newsgroups: borland.public.delphi.vcl.components.using
Date: 1998/02/07

Nelson,

since the error is triggered due to user action the only place where you
can easily trap it is the Application.OnException event. Attach a handler
to it (you have to do this in code, since the designer does not "see" the
Application object) and swallow the exception there.

Peter Below (TeamB)  100113.1101@compuserve.com)