mike.h on Tue, 16 Jul 2002 19:50:10 +0200


[Date Prev] [Date Next] [Thread Prev] [Thread Next] [Date Index] [Thread Index]

RE: [PLUG] [ON TOPIC] passing a pointer to an object to an object (c++)


Fred,

You do not appear to be declaring the local pointer varible in your snip:

voxInstallCommon::voxInstallCommon(QLabel *qlIncoming)
{
    QLabel *qlBillBoard=new QLabel("unlabeled", 0, 0);
    qlBillBoard=qlIncoming;
...
-mike

-----Original Message-----
From: plug-admin@lists.phillylinux.org
[mailto:plug-admin@lists.phillylinux.org]On Behalf Of Fred K Ollinger
Sent: Saturday, July 13, 2002 11:27 AM
To: plug@lists.phillylinux.org
Subject: [PLUG] [ON TOPIC] passing a pointer to an object to an object
(c++)


I have this code where I have an object and I'd like to modify it while in
another object. Is there a way to do this? I get segfaults when I do:

// begin snippet
voxInstallCommon::voxInstallCommon(QLabel *qlIncoming)
{
    qlBillBoard=new QLabel("unlabeled", 0, 0);
    qlBillBoard=qlIncoming;
//end snippet

Why?

Is there a better way to gain access to an oject in another object?

I have spent a lot of time reading about this and trying permutations to
no avail. I want the oject to be persistent in the other object.

I have successfully passed a pointer to an object in the function, but the
pointer is not persistent so I'm trying to do this via a constructor and
then make a pointer to the pointer. Since all the pointers are aiming at
the same patch of memory this should work, but it doesn't.

Fred Ollinger (follinge@sas.upenn.edu)
CCN sysadmin


______________________________________________________________________
Philadelphia Linux Users Group       -      http://www.phillylinux.org
Announcements-http://lists.phillylinux.org/mail/listinfo/plug-announce
General Discussion  -  http://lists.phillylinux.org/mail/listinfo/plug



______________________________________________________________________
Philadelphia Linux Users Group       -      http://www.phillylinux.org
Announcements-http://lists.phillylinux.org/mail/listinfo/plug-announce
General Discussion  -  http://lists.phillylinux.org/mail/listinfo/plug