C / C++ / MFC

Re: Upcasting &amp;amp;amp;amp;amp; Downcasting naming jargon ?

28-Dec-05 23:11

Let me mention the MSDN have not explicitly called it downcasting or even upcasting. Its the name STATIC_DOWNCAST which I thought implies downcasting but its for upcasting. So plz ppl dont get confused nor blame/curse MSDN. It may/may not be my fault or my understanding's fault. But one thing is clear the name jargon of STATIC_DOWNCAST for upcasting produces confusion.

Best Regards,

vikas amin28-Dec-05 23:25

vikas amin

28-Dec-05 23:25

No problme Mr Khan
u have a soft corner for MSDN
Cool | :cool:

Vikas Amin
Embin Technology
Bombay
vikas.amin@embin.com

Re: Upcasting &amp;amp;amp;amp;amp;amp; Downcasting naming jargon ?

Identity Undisclosed29-Dec-05 1:50

Re: Upcasting &amp;amp;amp;amp;amp;amp;amp; Downcasting naming jargon ?

29-Dec-05 1:50

abhi ghalti tow insaan say he hoti haina Wink | ;)

Best Regards

Prakash Nadar29-Dec-05 5:12

Prakash Nadar

29-Dec-05 5:12

Ibraheem Khan wrote:
abhi ghalti tow insaan say he hoti haina

no Hindi please Smile | :)

-Prakash

Re: Upcasting &amp;amp;amp;amp;amp; Downcasting naming jargon ?

Prakash Nadar29-Dec-05 4:46

Prakash Nadar

29-Dec-05 4:46

Read the documentation properly.

STATIC_DOWNCAST(class_name, pobject )
pobject must either be NULL, or point to an object of a class which is derived directly, or indirectly, from class_name.

So they are refering to upcasting but they have documented it as downcast but then i could not find a STATIC_UPCAST macro either.

and also this macro is part of the MFC framework.

-Prakash

Re: Upcasting &amp;amp; Downcasting naming jargon ?

sunit529-Dec-05 0:10

sunit5

29-Dec-05 0:10

What I know upcasting downcasting is related to dynamic_cast
not static_cast for this at least one virtual function must be present

never say die

LOGFILE AND BACKUP(MFC)

RabiaAslam28-Dec-05 20:19

RabiaAslam

28-Dec-05 20:19

This project is being specifically developed to facilitate easy collaboration within workgroup which provides improved and fast backup and recovery facility.
The objective of the software is to provide a platform to the people working at different locations but on a single project. This software will enable them to maintain a log file of all the files being viewed at every computer. These files along with the log file are then copied to the required destination. Hence in this way the users can keep in touch with each other’s activity and the overall progress.
The software will help in keeping track of the files visited during a day. In this way one can keep track of all the work done
The main functionality of the system is to provide the backup facility and recovery procedure for highly reliable and maintainable systems. Moreover, using the system a user can keep track of all the files that have been visited per day. Also the user can take the backup of the desired files using any portable media and provide the recovery of files in case of system/disk crash.
please tell me any solution. i am clear with the functinality. i want to know the MFC commands to go through this application. please help me and reply as soon as possible.

RabiaAslam

Re: LOGFILE AND BACKUP(MFC)

khan++29-Dec-05 1:52

khan++

29-Dec-05 1:52

Are those project files at one location? or are they copied to all systems? In both cases, a program will run on the PC where they files are located, and it will keep reading any changes to the files in the desired directory, like new file creation, file modification (date/time changes), deletion etc, and write to a log file. Then when the time comes to backup the files, the program can read-back the log in, and tell you what files have been modified and when, so you can take backups etc.

this is this.

Re: LOGFILE AND BACKUP(MFC)

Maximilien29-Dec-05 3:36

Maximilien

29-Dec-05 3:36

ok, third time in 24 hours ...

First, no one will give you a definitive answer to what you are asking, this look like s a HUGE project, and no single API exists for that, either MFC, win32 or other APIs.

Second, you should scope down the project to a sandbox type of environment, not keep track of ALL files on ALL computers, this is way overkill; and who cares ( In my opinion ) what files are viewed on someone else's computer, normally, only modified ( created, modified, renamed, deleted ) files are logged and be candidate to be transfered to other systems; only work on a specific folder, or a project type sandbox ( for example a VS project )

Third, you will need to implement a kind of Peer-2-Peer system, that will replicate data across different systems.

Have a look at what the groove system is doing ( www.groove.net ).

Maximilien Lincourt
Your Head A Splode - Strong Bad

Re: LOGFILE AND BACKUP(MFC)

Identity Undisclosed29-Dec-05 6:19

Problem in executing application

29-Dec-05 6:19

You can use system wide hooks and trap the messages of the opening a file. You can know the user name using simple APIs. But I am afraid no one will help in a detail what u are requesting.

For recovering data procedure, understand the windows file system probably and implement ur own algoirthms for retreiving lost pointers.

You can look abt hooks on the following link:-
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/winui/winui/windowsuserinterface/windowing/hooks.asp

Best Regards,

maharaja pandian28-Dec-05 20:01

maharaja pandian

28-Dec-05 20:01

hi,
i did one application VC++/MFC with graphical methods
when i execute the application . Its start running ,but after sometime
it throw an error message

"The instruction at "0x6c3b7f98" referenced memory at "0x00000048". The memory could not be "read".

Click on OK to terminate the program
Click on CANCEL to debug the program

what's the reason reply ASAP
Thanks
Maharaja Smile | :)

send reply

Re: Problem in executing application

sunit528-Dec-05 20:36

sunit5

28-Dec-05 20:36

pls post the code snippet and zero in the problem in the code snippet

never say die

Re: Problem in executing application

vikas amin28-Dec-05 23:28

vikas amin

28-Dec-05 23:28

Mr Maharaja
U r probably facing some memory problem
might be u have an pointer to some object
which is not initialised or is tried to
change .

I.E

char* temp="VIKAS_GOOD_PROGRAMER";
*temp='v';

This will cause similer error .
Cool | :cool:

Vikas Amin
Embin Technology
Bombay
vikas.amin@embin.com

Re: Problem in executing application

Identity Undisclosed29-Dec-05 1:52

29-Dec-05 1:52

vikas is right. To add more, u wud allocating some memory on the heap but not deallocating the memory. Make sure to use delete for every new. I hope u get the point !

Print Preview Crashes

Identity Undisclosed28-Dec-05 19:13

getting problem in ontimer(UINT nIDEvent)

28-Dec-05 19:13

When I click close button of CPrintPreview the application crashes. Before explaining what I have done, I find it noteworthy to mention that when application was launched from VC 6.0, no crash of application watsoever occured. But after migrating to VC.NET, I am encoutering this problem.
and let me focus what I have done:

I have derived a class from CPreviewPrint and call OnPreviewClose to close the print preview.
Since the class is derived from CPrintPreview it has a pointer names m_pPreviousView. Now plz just focus on the coming line. The problem starts after this. At this stage this->m_pPreviousView->m_pPreviewState is not NULL. But when I cast it CPreviousView and say store in pPrevView, I get pPrevView->m_pPreviewState NULL.

void MyPrintPreview::OnPreviewClose()
{
SetFocus();

/*
some code ... this->m_pPreviousView->m_pPreviewState is NOT NULL
*/

CPreviewView* pPreviewView = STATIC_DOWNCAST(CPreviewView, this);

/*
pPreviewView->m_pPreviousView->m_pPreviewState is NULL
some code and call OnEndPrintPreview
*/

}

Any help on it will be highly appreciated.
Best Regards,

cancerion28-Dec-05 19:09

28-Dec-05 19:09

hi
i want call OnTimer(UINT nIDEvent) in same class by using
SetTimer(4444,5000,NULL);
but i am unable to call ,it didn't go in OnTimer() body

can anyone help me.

thanks in advance

sachin

Owner drawn28-Dec-05 19:16

Owner drawn

28-Dec-05 19:16

cancerion wrote:
but i am unable to call

There is no need to call OnTimer. It's called everytime a WM_TIMER event is fired.

Did you add a message map entry for OnTimer. That is

ON_WM_TIMER()

Jesus Loves You and Me Smile | :)

<marquee direction="up" height="50" scrolldelay="1" step="1" scrollamount="1" style="background-color:'#44ccff'">
--Owner Drawn
--Nothing special
--Defeat is temporary but surrender is permanent
--Never say quits
--Jesus is Lord

cancerion28-Dec-05 19:34

28-Dec-05 19:34

hi ,
i have tried this there is no change in situation , while i have one application uaing this function , i have followed that ,still i m unable to do that

Owner drawn28-Dec-05 19:38

Owner drawn

28-Dec-05 19:38

How is OnTimer declared

Jesus Loves You and Me Smile | :)

cancerion28-Dec-05 20:15

28-Dec-05 20:15

afx_msg void OnTimer(UINT nIDEvent);

Owner drawn28-Dec-05 20:21

Owner drawn

28-Dec-05 20:21

This how I do...

BEGIN_MESSAGE_MAP(.......)
ON_WM_TIMER()
END_MESSAGE_MAP()

afx_msg void OnTimer(UINT nIDEvent);

SetTimer(timerID, delay, callback);

//rest of the code

void MyClassName::OnTimer(UINT nIDEvent)
{
.....
}

well it will work if it done like this...

Change the delay to 1000... So that you can check faster

Try again

Jesus Loves You and Me Smile | :)

cancerion28-Dec-05 20:42

28-Dec-05 20:42

thanks,

i think ,i have made a mistake in my main program . in which it's not working .i also made a program separately and it was working .so now i will make changes again in my main program

thanks once again