C / C++ / MFC

dsp-file for Visual Studio 6.0

3-Dec-04 9:31

Araj01 wrote:
am able to get what i needed.

It's all just a matter of asking the right question.

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

Reinhold442-Dec-04 11:01

Reinhold44

2-Dec-04 11:01

Hallo,

I am creating the dsp-file vor Visual Studio 6.0 by Hand and need urgendly any documentation for this purpose.

Who can give me some links???

thanks

Reinhold

killed for free std::string, Help please. I will give rate

LongIsland2-Dec-04 10:48

LongIsland

2-Dec-04 10:48

Hello, please help on the following code: Thanks a lot ahead. How I free the mem in the caller????? I can not modify the signature,btw

void caller()
{
std::string str = myfunc();

//free?
free((void*)str); //can not compile at all
free((void*)str.c_str()); //run time error
}

std::string myfunc()
{
//allocate some buffer to receive the socket data
void* pData = new/malloc ...
//make sure it is null terminated
std::string strRet = (const char*)pData;
return strRet;
}

Re: killed for free std::string, Help please. I will give rate

John R. Shaw2-Dec-04 15:08

John R. Shaw

2-Dec-04 15:08

You do not need to free the string, because std::string is a class, it will handle the freeing when caller() returns. Of course it you want to do it yourself, then just call str.clear().

std::string myfunc()
{
    // allocate buffer etc...
    ...
    // get data etc...
    ...
    // ok, if pData holds a null terminate c-str
    std::string strRet = (const char*)pData;
    // finished with pData, now free it
    ...
    return strRet;
}
//
// Problem with above: To many constructor calls.
// 1) std::string strRet = (const char*)pData;
// 2) std::string str = myfunc();
// In 2 you are copying from the string returned
// by myfunc() to the string in caller and then
// the string created in myfunc() is destroyed.
//
// Better myfunc() with 1 constructor call
bool myfunc(std::string& strRet)
{
    // allocate buffer etc...
    ...
    // get data etc...
    ...
    // ok, if pData holds a null terminate c-str
    strRet = (const char*)pData;
    // finished with pData, now free it
    ...
    // if we made it here, every thing is ok
    return true;
}

INTP
"The more help VB provides VB programmers, the more miserable your life as a C++ programmer becomes."
Andrew W. Troelsen

Re: killed for free std::string, Help please. I will give rate

Maximilien2-Dec-04 16:19

Maximilien

2-Dec-04 16:19

myFunc should free pData; the buffer is copied in the string; so it must be freed.

Maximilien Lincourt
Your Head A Splode - Strong Bad

removing the Main Frame title bar in a SDI

kdehairy2-Dec-04 10:42

2-Dec-04 10:42

Does any body knows how to remove the title bar and the menu from the main frame window in an SDI application with MFC ???

k_dehairy

David Crow2-Dec-04 10:45

2-Dec-04 10:45

I think that requires removal of the WS_CAPTION and WS_SYSMENU styles. However, I think there is more to it than this, but I've not tried.

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

kdehairy2-Dec-04 10:54

2-Dec-04 10:54

there certianly is more, cause I tried that and .. !!

Could you be kind and try with me ?

k_dehairy

Graham Bradshaw2-Dec-04 11:03

Graham Bradshaw

2-Dec-04 11:03

As luck would have it, I'm working on an application that does exactly that. Happy to share...

All code is in the CFrameWnd derived class.

to remove the menu and title bar:

// remove and destroy the old menu<br />
SetMenu(NULL);<br />
::DestroyMenu(m_hMenuDefault);<br />
m_hMenuDefault = NULL;<br />
<br />
// remove the title bar<br />
ModifyStyle(WS_CAPTION, 0);

to put them back:

// restore the title bar<br />
ModifyStyle(0, WS_CAPTION);<br />
<br />
// recreate the menu<br />
CMenu menu;<br />
<br />
menu.LoadMenu(IDR_MAINFRAME);<br />
SetMenu(&menu);<br />
m_hMenuDefault = menu.GetSafeHmenu();

kdehairy2-Dec-04 22:08

Why this code alway crash my app?Need help.

2-Dec-04 22:08

I guess I am lucky !! .. thanks very much
but..
I put the code in the OnCreate() in the CFrameWnd derived class. It worked with the menu. For the title bar it became not functioning but still here, visible.

Why is that?

and again thank you
---------------------------------
I just tried this now
It worked when I made a call to SetWindowPos()

but Why is that?

k_dehairy

Teerayoot2-Dec-04 9:47

Teerayoot

2-Dec-04 9:47

char buffer[1024]={0};

DWORD need=0;

HANDLE pt=0;
PRINTER_INFO_2 ptinfo={0};

OpenPrinterA("FinePrint",&pt,0);
GetPrinter(pt,2,(PBYTE)&ptinfo,0,&need); // calulate need size

// This line cause a ploblem.
GetPrinter(pt,2,(PBYTE)&ptinfo,need,&need);

// stack destroy here ,after go off this function EIP will point to invalid address

Also for crash for GetJobA,EnumJobA Api.

Urgently need help for my school project.
Thank you in advance.

David Crow2-Dec-04 10:26

2-Dec-04 10:26

The first thing that jumps out at me is the lack of error checking. Try

char    buffer[1024] = {0};
    DWORD   dwError,
            dwNeed=0;
    HANDLE  hPrinter = 0;
    PRINTER_INFO_2  ptinfo = {0};


    if (OpenPrinter("FinePrint", &hPrinter, NULL) != FALSE)
    {
        if (GetPrinter(hPrinter, 2, (PBYTE) &ptinfo, 0, &dwNeed) != FALSE)
            GetPrinter(hPrinter, 2, (PBYTE) &ptinfo, dwNeed, &dwNeed);
        else
            dwError = GetLastError();
    }
    else
        dwError = GetLastError();

and then see if the problem persists. If so, at least you'll know the cause.

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

Teerayoot3-Dec-04 2:26

Teerayoot

3-Dec-04 2:26

Thank you for help.
But not soleved.

if (GetPrinter(hPrinter, 2, (PBYTE) &ptinfo, 0, &dwNeed) != FALSE)
above line will evaluate to false(GetPrinter return false)
dwNeed = 1648

then else code will trigger

else dwError = GetLastError();
error code = 122 // The data area pass to system call is too small!

As my first post when i pass enough size (dwNeed) to GetPrinter program will crash !

More help please.

David Crow3-Dec-04 3:25

3-Dec-04 3:25

While the code snippets that I provide are meant to be syntactically correct, they may not always be logically correct. This is intentional. Try:

DWORD   dwError,
        dwNeed = 0;
HANDLE  hPrinter = 0;
PBYTE   pBuffer = NULL;
PPRINTER_INFO_2 pPrintInfo = NULL;
 
if (OpenPrinter("FinePrint", &hPrinter, NULL) != FALSE)
{
    GetPrinter(hPrinter, 2, NULL, 0, &dwNeed);
 
    pBuffer = new BYTE[dwNeed];
    if (GetPrinter(hPrinter, 2, pBuffer, dwNeed, &dwNeed) != FALSE)
    {
        pPrintInfo = (PPRINTER_INFO_2) pBuffer;
    }
 
    delete [] pBuffer;
}
else
    dwError = GetLastError();

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

Compilation Times in VS C++ .NET

Teerayoot3-Dec-04 4:48

Teerayoot

3-Dec-04 4:48

Ohh ,have to contruct the buffer first.

I will read your article alot to grap some of your programming skill.
Thank you very much.

haggersr2-Dec-04 8:17

haggersr

2-Dec-04 8:17

I am experiencing very slow compilation times in VS C++ .NET vs. version 6.0. Has anybody had this experience?

Steve

resizing dialog box

haseeb_saeed2-Dec-04 8:05

haseeb_saeed

2-Dec-04 8:05

Being a beginner, i am having quite alot problem in changing a size of a dialog box to another specific size..more precisely i wish to make a calculator like the one windows have .i have created a standard one and have added a menu but am having a problem in changing the size when the scientific tab is pressed in the menu.... please help me in this respect and please try to explain a bit....

thankyou

haseeb

kdehairy2-Dec-04 10:37

2-Dec-04 10:37

well ..
sizing a dialog is a little bit deferent than other kind of windows, because of its measuring units.
In a dialog when you say that width = 100, it doesn't mean 100 pixels (!!) it means 100 dialog units (depends on the font you are using in the dialog).

open user dialog resource in the visual c++ and look at the status bar (right most), you will find the size of your dialog in dialog units.

so,
1- write down size of your dialog when in the scientific mode (from the status bar), these are in the dialog measuring units.

2-
...

<br />
CRect rect;<br />
rect.left = 0;<br />
rect.top = 0;<br />
//replace Width with the value of width you wrote<br />
rect.right = Width;<br />
//replace Height with the value of height you wrote<br />
rect.bottom = Height;<br />
//Call this function which converts the dialog units<br />
//into pixel units and pass it a pointer to rect<br />
MapDialogRect(&rect);<br />

now you have the new size in pixel units. you can use it freely.

3- Call the function SetWindowPos() and give it the width and height of the rect.

I suggest you move with the debugger to watch the change in the units after the MapDialogRect() call.

hope it is helpfull

good luck

k_dehairy

haseeb_saeed3-Dec-04 3:01

haseeb_saeed

3-Dec-04 3:01

thanx alot ... probably now i would be able to achieve my goal....

thanx...
haseeb

haseeb

John R. Shaw2-Dec-04 16:06

John R. Shaw

2-Dec-04 16:06

Actualy the Windows calculator probably does not resize at all. It most likely consist of 2 different dialog boxes. When the user decides to switch caculator views, that is what it does.

1) Create 2 dialog boxes: normal and scientific.
Remember to use the same IDs for the buttons, etc... that do the same thing.
2) Create a CDialog based class for the scientific dialog only, since you only need one class to handle all the commands.
3) Now when the user selects a new veiw call EndDialog(some known value).
Example:

if( dialogID == IDD_NORMAL )
    EndDialog(IDD_SCIENTIFIC).
else
    EndDialog(IDD_NORMAL).

4) Finaly your code calling DoModal() (to show your dialog) needs to look something like this:

...
int result = IDD_NORMAL.
do {
    if( result != IDD_NORMAL || result != IDD_SCIENTIFIC )
        break; // something happen that should not have
    { // required
        CMyDialog dlg(result);
        result = dlg.DoModal
    } // dlg destroyed here
  // FYI: IDOK = 1, IDCANCEL = 2
} while( result != IDOK && result != IDCANCEL );

Any way that is most likely how I would do it. You ought to be able to figure out the rest.

Good Luck!

INTP
"The more help VB provides VB programmers, the more miserable your life as a C++ programmer becomes."
Andrew W. Troelsen