?
Solved

Saving List Items to Disk

Posted on 2003-11-04
8
Medium Priority
?
220 Views
Last Modified: 2013-11-20
I have the following code in my project:

void CIRCServerConnector::SaveServerList(void)
{
      CFile fileServLst("servlist.dat", CFile::modeCreate | CFile::modeReadWrite);

      CArchive arStore(&fileServLst, CArchive::store);

      POSITION aPos = m_listServers.GetHeadPosition();
      CIRCServer* temp;

      while(aPos)
      {
            temp = m_listServers.GetNext(aPos);
            arStore.WriteObject(temp);
      }
      arStore.Close();
}

It is supposed to go through a CTypedPtrList and save each item to disk..one by one. Right now...I am getting a dialog box that pops up and says "An unsupported operation was attempted"...never seen that before. Can anyone help tell me what is going on here?
0
Comment
Question by:SGyves
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 5
  • 2
8 Comments
 
LVL 23

Expert Comment

by:Roshan Davis
ID: 9684129
Attempting to retrieve a CIRCServer* on any other object will result in a system error (the utterly enigmatic "An unsupported operation was attempted"), MSDN documented something like this.

can u tell me, in which point of code that error comes..?

Rosh :)
0
 
LVL 9

Accepted Solution

by:
Priyesh earned 1600 total points
ID: 9684172
Just a reminder list, you might be already doing this.

class CIRCServer : public CObject//derive from cobject to
{
  DECLARE_SERIAL(CIRCServer)
public:
   void Serialize(CArchive& ar) ;
public:
   CString szName ;
};

IMPLEMENT_SERIAL(CIRCServer, CObject, 1)//needed to enable serialization

void CIRCServer::Serialize(CArchive& ar)//Called by WriteObject
{
   if(ar.IsLoading())
     ar >> szName ;
   else
     ar << szName ;  
}

And, a try - catch to catch CArchiveException or others to get any further details abt the error
0
 

Author Comment

by:SGyves
ID: 9684336
Rosh...it happens right on the WriteObject line:

arStore.WriteObject(temp);


that one.
0
What does it mean to be "Always On"?

Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.

 

Author Comment

by:SGyves
ID: 9684340
OMG...I think I forgot the IMPLEMENT_SERIAL and DECLARE_SERIAL statements.   (Slapping my head)

0
 

Author Comment

by:SGyves
ID: 9684342
A long day indeed...that was it.
0
 

Author Comment

by:SGyves
ID: 9684585
Hey...what is the best way to read these back from disk untill there are no more....meaning...how can I check for EOF??
0
 
LVL 9

Expert Comment

by:Priyesh
ID: 9684799
Would this work for you??

      CIRCServer clsServer ;
      clsServer.szName = "IRCServer" ;

      CTypedPtrArray<CObArray, CIRCServer*> clsArraySave, clsArrayLoad ;
      clsArraySave.Add(&clsServer) ;

//Write.
      {
            CFile clsFile("c:\\ircobjects.dat", CFile::modeCreate|CFile::modeWrite) ;
            CArchive ar(&clsFile, CArchive::store) ;
            clsArraySave.Serialize(ar) ;
      }


//Read
      {
            CFile clsFile("c:\\ircobjects.dat", CFile::modeRead) ;
            CArchive ar(&clsFile, CArchive::load) ;
            clsArrayLoad.Serialize(ar) ;

            CIRCServer* pServer = clsArrayLoad.GetAt(0) ;
            TRACE("Name = %s\n", pServer->szName) ;
      }

0
 

Author Comment

by:SGyves
ID: 9687910
Yes...I believe that will work. As I understand...the serialize for the CTypedPtrList serializes all elemnts into the file. Cool.
0

Featured Post

Moving data to the cloud? Find out if you’re ready

Before moving to the cloud, it is important to carefully define your db needs, plan for the migration & understand prod. environment. This wp explains how to define what you need from a cloud provider, plan for the migration & what putting a cloud solution into practice entails.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Introduction: Database storage, where is the exe actually on the disc? Playing a game selected randomly (how to generate random numbers).  Error trapping with try..catch to help the code run even if something goes wrong. Continuing from the seve…
In this post we will learn different types of Android Layout and some basics of an Android App.
This video will show you how to get GIT to work in Eclipse.   It will walk you through how to install the EGit plugin in eclipse and how to checkout an existing repository.
Have you created a query with information for a calendar? ... and then, abra-cadabra, the calendar is done?! I am going to show you how to make that happen. Visualize your data!  ... really see it To use the code to create a calendar from a q…

649 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question