C / C++ / MFC

1-Jan-09 20:11

Do you like to more explain about your problem I cant see your monitor its so far?

Of one Essence is the human race
thus has Creation put the base
One Limb impacted is sufficient
For all Others to feel the Mace
(Saadi )

Re: Compile time errors

PCuong19831-Jan-09 21:25

PCuong1983

1-Jan-09 21:25

Oopt!
where is your codes that generated these error ?

sprintf?

dec821-Jan-09 18:45

dec82

1-Jan-09 18:45

void *ptrList [30];
char ss [40];
for (i = 0; i<26; i++)
{
if (ptrList [i])
sprintf(ss, "%s", *(CString *) ptrList [i]);
}

What do those code do?
Thanks.

Nibu babu thomas1-Jan-09 18:58

Nibu babu thomas

1-Jan-09 18:58

hung1984 wrote:
if (ptrList [i])
sprintf(ss, "%s", *(CString *) ptrList [i]);

From the code...

ptrList is an array of CString pointers which for some reason is kept as void pointers, but the developer knows it's internally CString* so he is "confidently" casting it to CString* then copying the CString value to a character buffer (ss).

Confusing at times and also he forgot another step to cast *(CString*) to LPCTSTR and to use _stprintf instead of sprintf.

So after correction the code will look like...

void *ptrList [30];
char ss [40];
for (i = 0; i<26; i++)
{
  if (ptrList [i])
  {
    LPCTSTR lpctszStr = (LPCTSTR)(*(CString *) ptrList [i]);
    _stprintf(ss, "%s", lpctszStr);
  }
}

Nibu babu thomas
Microsoft MVP for VC++

Code must be written to be read, not by the compiler, but by another human being.

Programming Blog: http://nibuthomas.wordpress.com

ThatsAlok1-Jan-09 19:02

ThatsAlok

1-Jan-09 19:02

hung1984 wrote:
if (ptrList [i])
sprintf(ss, "%s", *(CString *) ptrList [i]);

it's copying content of ptlist to ss!

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dec821-Jan-09 21:10

dec82

1-Jan-09 21:10

what the statement for if here ?
if (ptrList [i])

PCuong19831-Jan-09 21:56

PCuong1983

1-Jan-09 21:56

You just only declare a array of void pointer like void* ptrList[30]; and no initialize for them.
so ptrList[i] point to a value that has no type (and thus also an undetermined length and undetermined dereference properties). ptrList[i] is now == 0x??????????
and if(ptrList[i]) is now similar if(true)
let me know if i am wrong

David Crow2-Jan-09 4:01

David Crow

2-Jan-09 4:01

Can't you just use the debugger to find out? Otherwise, you're just programming "in the dark."

"Love people and use things, not love things and use people." - Unknown

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Problem in Fit to Page Width Printing.

Stephen Hewitt3-Jan-09 22:05

Stephen Hewitt

3-Jan-09 22:05

Looks like bad code to me.

Steve

Le@rner1-Jan-09 18:39

Le@rner

1-Jan-09 18:39

Hi all,

I m using a List control of Report view type.
Item text in list control display in sigle line.

There are many column when i print data of list control all column are not print .

i want to use property fit to page width.

i want all column are print with full data.

please tell me how can i do this.

thanks in advance.

IN A DAY, WHEN YOU DON'T COME ACROSS ANY PROBLEMS - YOU CAN BE SURE THAT YOU ARE TRAVELLING IN A WRONG PATH

Hamid_RT1-Jan-09 20:17

1-Jan-09 20:17

$h@nky_ with another problem about print how did you try to print them?

Of one Essence is the human race
thus has Creation put the base
One Limb impacted is sufficient
For all Others to feel the Mace
(Saadi )

Le@rner1-Jan-09 20:22

Le@rner

1-Jan-09 20:22

there is only one problem that is fit to page width remain other problems are now short out.

thats why i need a help from u.

IN A DAY, WHEN YOU DON'T COME ACROSS ANY PROBLEMS - YOU CAN BE SURE THAT YOU ARE TRAVELLING IN A WRONG PATH

Hamid_RT1-Jan-09 20:55

1-Jan-09 20:55

I think you will get your answer of troduction to MFC Printing[^].

Of one Essence is the human race
thus has Creation put the base
One Limb impacted is sufficient
For all Others to feel the Mace
(Saadi )

The program reads and writes hard disk in a thread heavily, how to make it work when idle?

Le@rner1-Jan-09 22:32

Le@rner

1-Jan-09 22:32

Sir i m already check this article.

i think u dont understand my problem.

printing is done in my application.but the problem is that if List have 15 column and according the Page width all 15 are not print.

i want to adjust columns width according to page width.

thats why all number of column are print.

IN A DAY, WHEN YOU DON'T COME ACROSS ANY PROBLEMS - YOU CAN BE SURE THAT YOU ARE TRAVELLING IN A WRONG PATH

followait1-Jan-09 18:07

followait

1-Jan-09 18:07

The program do a lot of hard disk reading and writing,
so other application became very slow,
any way to make it work when the hard disk is not busy?

Re: The program reads and writes hard disk in a thread heavily, how to make it work when idle?

Jijo.Raj1-Jan-09 23:57

Jijo.Raj

1-Jan-09 23:57

My suggestion is to use Memory Mapped Files[^]. It will definitely improve the file access performance. You can use CMemMapFile[^] class for making your task easier.

Just try it and check whether the MemoryMapped files improves the performance in your case. Good Luck!

Regards,
Jijo.

_____________________________________________________

http://weseetips.com[^] Visual C++ tips and tricks. Updated daily.

Multithreading

hrishiS1-Jan-09 18:00

hrishiS

1-Jan-09 18:00

Hi Experts,
I am learning threading concept in vc++. I have gone through the basics.
I would like to clear my doubts for the following.

1. when do we used
. a. afxBeginthread
. b. beginThread
. c. createThread

2. to communicate between different threads

3. thread synchronisation.

Could u please advice me any link (or if I can get any documents) from where I can learn the same ( specially for point 2 and 3 )

Thank You So much in advance
Himangshu
Bangalore

Hamid_RT1-Jan-09 18:09

1-Jan-09 18:09

See C++ Multithreading Tutorial[^].

Of one Essence is the human race
thus has Creation put the base
One Limb impacted is sufficient
For all Others to feel the Mace
(Saadi )

hrishiS1-Jan-09 18:18

hrishiS

1-Jan-09 18:18

thax a lot for ur reply hamid....I will go through it and post here again

hrishiS1-Jan-09 18:30

hrishiS

1-Jan-09 18:30

Hi hamid,

Its a perfect docs. But, I guess it gives the details of threads and synchronisation mechanism...Can u pls advice anything from where I will get the details of communication between thread?

Thx
Himangshu