C / C++ / MFC Discussion Boards

Anonymous5-Sep-02 19:33

5-Sep-02 19:33

I implemented a base class CMyViewBase, there's a function CreateMyChild(xxxxx ... ) which has to put in a CWnd * as the parent.

However, it can only be known in the derived class only, such that my classes are derived from CTabCtrl, CView also. How can a child know that ??

Can my derived class using "virtual" CMyViewBase in declare inheritance, and my base class using public CWnd ?

I dont know...

Coremn5-Sep-02 19:27

Coremn

5-Sep-02 19:27

Sorry about this, does anyone know what the following code does

<br />
<br />
DWORD Thing::GetDiviceFreeSpace(LPCTSTR lpszPath)<br />
{<br />
        struct statfs sStats;<br />
        if(statfs(lpszPath,&sStats)== -1)<br />
                return 0;<br />
        return sStats.f_bsize * sStats.f_bavail;<br />
<br />
}<br />

I found it in some project I am working on, confusing

---
Why are all the good signitures taken already? Roll eyes | :rolleyes:

Re: I dont know...

Christian Graus5-Sep-02 20:17

Christian Graus

5-Sep-02 20:17

You need to know what the struct is in order to know what it does. the statfs struct must be defined somewhere else for this to do anything. Search MSDN, if it's not there, search your code.

Christian

Hey, at least Logo had, at it's inception, a mechanical turtle. VB has always lacked even that... - Shog9 04-09-2002

Cats, and most other animals apart from mad cows can write fully functional vb code. - Simon Walton - 6-Aug-2002

Re: I dont know...

markkuk5-Sep-02 23:03

markkuk

5-Sep-02 23:03

Is the code from an Unix/Linux program? statfs() appears to be a Linux or BSD Unix syscall, on Linux the documentation says:

       int statfs(const char *path, struct statfs *buf);
       int fstatfs(int fd, struct statfs *buf);

DESCRIPTION
       statfs  returns  information  about a mounted file system.  path is the
       path name of any file within the mounted filesystem.  buf is a  pointer
       to a statfs structure defined as follows:

              struct statfs {
                 long    f_type;     /* type of filesystem (see below) */
                 long    f_bsize;    /* optimal transfer block size */
                 long    f_blocks;   /* total data blocks in file system */
                 long    f_bfree;    /* free blocks in fs */
                 long    f_bavail;   /* free blocks avail to non-superuser */
                 long    f_files;    /* total file nodes in file system */
                 long    f_ffree;    /* free file nodes in fs */
                 fsid_t  f_fsid;     /* file system id */
                 long    f_namelen;  /* maximum length of filenames */
                 long    f_spare[6]; /* spare for later */
              };

Re: I dont know...

jhwurmbach5-Sep-02 20:15

jhwurmbach

5-Sep-02 20:15

Coremn wrote:
Sorry about this, does anyone know what the following code does

DWORD Thing::GetDiviceFreeSpace(LPCTSTR lpszPath)<br />

may very well get a devices free space.
statfs() sounds very much like "STATatus of FileSystem", so this would also fit in.
Third, a search in MSDN showed statfs() to be a "NFS Version 2 RPC Call", the description being 'Get file system attributes'.

Hope this helped

PS. I charge you 30 Dollar for information retrieval service. Poke tongue | ;-P

Re: I dont know...

Coremn5-Sep-02 20:56

Coremn

5-Sep-02 20:56

Thanks dudes - it will help
The cheque is in the mail. Smile | :)

---

How to access C++ Lib by using Java?

blongtq5-Sep-02 19:00

blongtq

5-Sep-02 19:00

Hello all,
Is there anyway to access C++ Library by using Java (Pure Java)? If yes, please give me some instructions.
Thank you very much.
Long Truong

Re: How to access C++ Lib by using Java?

Stephane Rodriguez.5-Sep-02 21:17

Stephane Rodriguez.

5-Sep-02 21:17

Aren't you a little bit offtopic here ?

Try this one.

God luck,

And I swallow a small raisin.

I doubt in CRichEditCtrl

sonshiro5-Sep-02 18:52

sonshiro

5-Sep-02 18:52

I know that CRichEditCtrl::SetSel(0,-1) will select all text in richedit control. But I don't understand about GetSel(). When I call CRichEditCtrl::GetSel(nStart, nEnd) to get selection range (after I called CRichEditCtrl::SetSel(0,-1)). Why the range is greater than text length.
Example:
- current text is "Hello". (text length = 5)
- then I call CRichEditCtrl::SetSel(0,-1).
- and then I call CRichEditCtrl::GetSel(nStart, nEnd).
- the result is nStart=0 and nEnd=7.
?? Why nEnd is not equal 5? What is the two addition?

Re: I doubt in CRichEditCtrl

.dan.g.5-Sep-02 19:45

.dan.g.

5-Sep-02 19:45

maybe its a 'carriage return\linefeed' pair on the end.

Multithreading

pankajdaga5-Sep-02 17:11

pankajdaga

5-Sep-02 17:11

I have the following encapsulation of a CriticalSection and Lock (out of my school textbook)

class Mutex
{
friend class Lock;
public:
Mutex () { InitializeCriticalSection (& _critSection); }
~Mutex () { DeleteCriticalSection (& _critSection); }
private:
void Acquire ()
{
EnterCriticalSection (& _critSection);
}
void Release ()
{
LeaveCriticalSection (& _critSection);
}

CRITICAL_SECTION _critSection;
};

class Lock
{
public:
// Acquire the state of the semaphore
Lock ( Mutex & mutex )
: _mutex(mutex)
{
_mutex.Acquire();
}
// Release the state of the semaphore
~Lock ()
{
_mutex.Release();
}
private:
Mutex & _mutex;
};

In the mutex class, why is the private member stored by reference? That is the line Mutex & _mutex;

I am asking, coz I used the classes for a school project and missed the &. My program crashed windows and it took me 6 hours to find the missing &! Why is it necessary to store it by reference?

Pankaj

Without struggle, there is no progress

Re: Multithreading

C^hris L^osinger5-Sep-02 18:12

C^hris L^osinger

5-Sep-02 18:12

when you pass an object by value, a copy of the object is created and passed to the function. this object will go out of scope and its destructor will be called, when the function exits.

when you pass by reference, the function uses the original object (via a pointer) and, so the object doesn't go out of scope when the function exits (and the destructor is not called).

a quick glance at your code...

the Mutex destructor deletes the critical section, possibly while some code is using it.

-c

Argue for your limitations, and sure enough, they're yours.

Re: Multithreading

Todd Smith6-Sep-02 18:46

Todd Smith

6-Sep-02 18:46

You should probably add a flag to your Mutex class indicating whether or not the cs has been acquired:

<br />
void Acquire ()<br />
{<br />
    if (!bAcquired) <br />
        EnterCriticalSection (& _critSection);<br />
    else<br />
        assert(!"Something is fishy!");<br />
    bAcquired = true;<br />
}<br />
<br />
void Release ()<br />
{<br />
    if (bAcquired)<br />
        LeaveCriticalSection (& _critSection);<br />
    else<br />
        assert(!"Something is fishy!");<br />
    bAcquired = false;<br />
}<br />

Todd Smith

procompile question

Year5-Sep-02 17:09

Year

5-Sep-02 17:09

Build output message "Build : warning : failed to (or don't know how to) build 'D:\SFS\Debug\NMSV3r1.pch'"

I already configure my project correctly, and rebuild all the project,
but still can't complile my project, why?

thanks.

Re: procompile question

Christian Graus5-Sep-02 17:21

Christian Graus

5-Sep-02 17:21

your pch file should not be part of your project, there is no reason to tell the compiler to try to compile a precompiled header.

Christian

Hey, at least Logo had, at it's inception, a mechanical turtle. VB has always lacked even that... - Shog9 04-09-2002

Cats, and most other animals apart from mad cows can write fully functional vb code. - Simon Walton - 6-Aug-2002

Accessing the Internet

Nay205-Sep-02 16:21

Nay20

5-Sep-02 16:21

How do I access the web with a CButton? Confused | :confused:

Out
Nay20

Re: Accessing the Internet

Jason Henderson5-Sep-02 16:25

Jason Henderson

5-Sep-02 16:25

Huh?

I think you need to be more clear with your question.
Do you want to just open a web page or what?

Jason Henderson
_{start page}
^articles
^{"If you are going through hell, keep going." - Sir Winston Churchill}

CTime and CString

monrobot135-Sep-02 16:02

monrobot13

5-Sep-02 16:02

Does anyone know if there's an easy (or even possible way) to convert a CString object to a CTime object?

Any help would be much appreciated.

Monrobot13

Re: CTime and CString

Jason Henderson5-Sep-02 16:28

Jason Henderson

5-Sep-02 16:28

Use COleDateTime::ParseDateTime() then construct a CTime using the hours, minutes, and seconds.

Jason Henderson
_{start page}
^articles
^{"If you are going through hell, keep going." - Sir Winston Churchill}

Re: CTime and CString

anju5-Sep-02 18:26

anju

5-Sep-02 18:26

Hi monrobot13
In my project i am using like this,
if you find a better way than this inform to me.
-------------------------------------------------
CTime StrToDate(char * buffer)//char *buffer CString object
{

int dd,mm,yy,H,M,S;
dd=0;mm=0;yy=0;H=0;M=0;S=0;

CString stemp;
stemp.Format("%c%c",buffer[0],buffer[1]);//date
dd=atoi(stemp);
stemp.Format("%c%c",buffer[3],buffer[4]);//month
mm=atoi(stemp);
stemp.Format("%c%c",buffer[6],buffer[7]);//Year
yy=atoi(stemp);
yy=yy+2000;
stemp.Format("%c%c",buffer[9],buffer[10]);//Hour
H=atoi(stemp);
stemp.Format("%c%c",buffer[12],buffer[13]);//Minute
M=atoi(stemp);
stemp.Format("%c%c",buffer[15],buffer[16]);//Seconds
S=atoi(stemp);

CTime time(yy,mm,dd,H,M,S);

return time;
--------------------------------------------------

anju

Images in CListCtrl report columns

IGx895-Sep-02 15:50

IGx89

5-Sep-02 15:50

I'm adding images (through an image list which gets the images from icons in my resources) into the columns of my report-style list control, but the images are never transparent, even though I'm using the screen color in my icons, and I specified ILC_MASK when I created my image list.

What am I doing wrong?

Thanks!

How can I know which computer access the file of my computer?

Member 18556085-Sep-02 13:49

Member 1855608

5-Sep-02 13:49

I want to monitor my computer's share directory in the LAN, when some files are deleted or renamed or modified by other computer. I can recored it.
but I don't know all this being done by which computer! How can i do it ?
Thanks a lot!
How can I know which remote computer access which file of my computer?
How can I finished it with MFC or VC?

Sending mail ...

Hadi Rezaee5-Sep-02 12:57

Hadi Rezaee

5-Sep-02 12:57

Hi there,
Is there anyway to send mail without using Oulook ???
Could you show me example, please ?

My month article: Game programming by DirectX by Lan Mader.
Please visit in: www.geocities.com/hadi_rezaie/index.html

Hadi Rezaie

Re: Sending mail ...

C^hris L^osinger5-Sep-02 13:14

C^hris L^osinger

5-Sep-02 13:14

http://www.codeproject.com/internet/cmapi.asp

Argue for your limitations, and sure enough, they're yours.

Re: Sending mail ...

Hadi Rezaee5-Sep-02 13:26

Hadi Rezaee

5-Sep-02 13:26

Thanks again ! Wink | ;)

Your helps are always useful for me Smile | :)

Regards

My month article: Game programming by DirectX by Lan Mader.
Please visit in: www.geocities.com/hadi_rezaie/index.html

Hadi Rezaie

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