Re: about breakpoints in VC++ - C / C++ / MFC Discussion Boards

Andrew Walker24-Dec-04 1:06

24-Dec-04 1:06

std::ifstream isn't designed to allow the reading of the entire filesize. The function _filelength in <io.h> will give you the length of a file. Be warned that this function is limited to the size of a long, so for very large files you'll need to use a platform dependant API (See MSDN).

The following function taken from the boost::regex sample code (regex_grep_example1.cpp) is one example of how to efficiently and safely allocate space using std::string. This is not the simplest solution, it is flexible. However without profiling this is micro-optimisation that probably isn't going to help. Note the use of reserve and capacity to ensure appropriate growth system for you buffers. You may be able to tweak initial size and growth rates if you know roughly what size the file will be.

void load_file(std::string& s, std::istream& is)
{
   s.erase();
   if(is.bad()) return;
   s.reserve(is.rdbuf()->in_avail());
   char c;
   while(is.get(c))
   {
      if(s.capacity() == s.size())
         s.reserve(s.capacity() * 3);
      s.append(1, c);
   }
}

If you can keep you head when all about you
Are losing theirs and blaming it on you;
If you can dream - and not make dreams your master;
If you can think - and not make thoughts your aim;
Yours is the Earth and everything that's in it.

Rudyard Kipling

How to display a Message when click on a Edit Box Scroll bar ?

pubududilena23-Dec-04 22:17

pubududilena

23-Dec-04 22:17

hi all,
I have added Edit Box to MFC Dialog base Program.I also activated auto Horizontal Scroll Bar and Vertical Scroll bar..

How do I show a Message (say "hellow") when click on a Scroll bar of that edit box.?
If any know that please reply me...

Thanks in advance..

Re: How to display a Message when click on a Edit Box Scroll bar ?

Aamir Butt23-Dec-04 22:31

Aamir Butt

23-Dec-04 22:31

Add Message Handlers for EN_HSCROLL and EN_VSCROLL messages and display MessageBox there.

Now, I hope you know how to add message handlers. If you dont, u can find it in any basic level MFC Book.

Regards,

Still Alone in this beautiful world Frown | :(

My Articles

Re: How to display a Message when click on a Edit Box Scroll bar ?

pubududilena23-Dec-04 22:40

pubududilena

23-Dec-04 22:40

hi,
I added that messages to Application..
void CA1Dlg::OnVScroll(UINT nSBCode, UINT nPos, CScrollBar* pScrollBar)
{
AfxMessageBox("hi");
CDialog::OnVScroll(nSBCode, nPos, pScrollBar);
}

But it is not working and not displying the Message
I have used MFC Dialog wizard to create the Application..

thanks in advance

can i make command buttons in vc++(like vb)

siva_nkl3323-Dec-04 21:47

siva_nkl33

23-Dec-04 21:47

i want to know about is it possible to have a command button in vc++ like in vb6.

Re: can i make command buttons in vc++(like vb)

ThatsAlok23-Dec-04 22:47

ThatsAlok

23-Dec-04 22:47

Yeah Why noT every Thing that is possible in VB is possible in vc also.

siva_nkl33 wrote:
command button

Use CButton if you are using MFC
use HBUTTON hBut=(HBUTTON)CreateWindow("BUTTON"......); in WIN32apis

"I Think this Will Help"
Alok Gupta
visit me at http://www.thisisalok.tk

about breakpoints in VC++

grace_sonal23-Dec-04 21:05

grace_sonal

23-Dec-04 21:05

I am getting an error as"Breakpoint has been reached"

while using VC++ rich edit text box
Can anybody help me find solution
Grace

Re: about breakpoints in VC++

mirex25-Dec-04 7:35

mirex

25-Dec-04 7:35

Try rebuilding the project. Or just ignore it and run program further by pressing F5.

Template class and header files

Imtiaz Murtaza23-Dec-04 19:01

Imtiaz Murtaza

23-Dec-04 19:01

Dear friends,
I am declaring a template class in header file and defining its methods in cpp file. As such i am getting an error of "unresolved external symbols" whenever i create object of this class.

Instead, if i define the methods in *.h file and remove cpp file, the errors are removed and program runs fine. Can anyone tell me whats the problem:

////////////////////////////////////////////////////////////////////////////
// File MyTemplate.h
template <class T> class TMyTemplate
{
public :

TMyTemplate();
~TMyTemplate();
};

template <class T>
TMyTemplate<T>::TMyTemplate()
{

}

template <class T>
TExpandableBuffer<T>::~TExpandableBuffer()
{
}
/////////////////////////////////////////////////////////////////

i.e i declared and defined functions in header file and this works fine for me. But if i remove the methods definition from header to cpp file the compiler starts giving me error of "Unresolved External Symbols" whenever i create object of class like:

TMyTemplate<char> myTemplate;

Imtiaz

Re: Template class and header files

Michael Dunn23-Dec-04 21:08

Michael Dunn

23-Dec-04 21:08

That's just how templates work. See the C++ FAQ Lite:
[34.14] How can I avoid linker errors with my template classes?[^]

--Mike--
LINKS~! Ericahist | 1ClickPicGrabber | CP SearchBar v2.0.2 | C++ Forum FAQ | You Are Dumb

how to call exe file in vc++

vc-programmer-23-Dec-04 17:31

vc-programmer-

23-Dec-04 17:31

how to call vc++ exe from another vc++ exe file
can i call??

Re: how to call exe file in vc++

parths23-Dec-04 18:03

parths

23-Dec-04 18:03

ShellExecute[^]

also the C 'system' function. try google to search for it

"It was when I found out I could make mistakes that I knew I was on to something."
-Ornette Coleman

"Philosophy is a study that lets us be unhappy more intelligently."
-Anon.

Re: how to call exe file in vc++

pavanbhai23-Dec-04 18:43

pavanbhai

23-Dec-04 18:43

To Call Exe File in VC ++ you have to use the Buildin Function

"Private Declare Function ShellExecute Lib "shell32.dll" Alias "ShellExecuteA" (ByVal hwnd As Long, ByVal lpOperation As String, ByVal lpFile As String, ByVal lpParameters As String, ByVal lpDirectory As String, ByVal nShowCmd As Long) As Long"

Hwnd as user Handle
lpOperation as operation i.e. "open","print"
lpFile as path of exe file

thanks,

Pavanbhai Pawar
Software Programmer,
Trans Tech Projects Pvt. Ltd.
Pune 411 004.
Mob: 9225527829
E-Mail Id:pawar@transtechprojects.com
Personal ID : pavanbhai_pawar@yahoo.com

Re: how to call exe file in vc++

Sarfraz Anwar23-Dec-04 18:18

Sarfraz Anwar

23-Dec-04 18:18

you can use ShellExecute to call any exe from ur application

Re: how to call exe file in vc++

ThatsAlok23-Dec-04 18:21

ThatsAlok

23-Dec-04 18:21

theer are numerous apis for achieving that like

<ul>
<li>ShellExecute/ShellExecuteEx
<li>WinExec
<li>CreateProcess
</ul>

Re: how to call exe file in vc++

Member 45151623-Dec-04 18:43

Member 451516

23-Dec-04 18:43

HANDLE hProcess = NULL;
SHELLEXECUTEINFO shellInfo;
::ZeroMemory(&shellInfo, sizeof(shellInfo));
shellInfo.cbSize = sizeof(shellInfo);
shellInfo.fMask = SEE_MASK_FLAG_NO_UI | SEE_MASK_NOCLOSEPROCESS;
shellInfo.lpFile = your app file;
shellInfo.lpParameters = NULL;
if(::ShellExecuteEx(&shellInfo))
{ /* success */
hProcess = shellInfo.hProcess;
if(hProcess != NULL){
::WaitForSingleObject(hProcess, INFINITE);
::CloseHandle(hProcess);
}
}

Re: thank...can i pass parameter

vc-programmer-23-Dec-04 19:56

vc-programmer-

23-Dec-04 19:56

can i pass parameter exe to another exe..
pls tell me... again...

thank u so much..

Re: thank...can i pass parameter

Member 45151623-Dec-04 20:07

Member 451516

23-Dec-04 20:07

yes. ...
ex: shellInfo.lpFile = _T("e_airyun.exe");

Re: how to call exe file in vc++

Michael Dunn23-Dec-04 21:41

Michael Dunn

23-Dec-04 21:41

See the FAQ
6.4 How do I run another program from my program?[^]

--Mike--
LINKS~! Ericahist | 1ClickPicGrabber | CP SearchBar v2.0.2 | C++ Forum FAQ | You Are Dumb

How to change the font of a owner-drawn menu

max_xiayi23-Dec-04 14:40

max_xiayi

23-Dec-04 14:40

?
please contact:
max_xiayi@hotmail.com

Re: How to change the font of a owner-drawn menu

Michael Dunn23-Dec-04 22:18

Michael Dunn

23-Dec-04 22:18

The same way as when doing any other drawing, select the font you want into the device context.

--Mike--
LINKS~! Ericahist | 1ClickPicGrabber | CP SearchBar v2.0.2 | C++ Forum FAQ | You Are Dumb

Re: How to change the font of a owner-drawn menu

ana_v12321-Sep-05 21:00

ana_v123

21-Sep-05 21:00

Please let me know, I also want to know if anyone has got a solution ?

Thanks in advance.
Ana

How To create a window in MFC dynamically

Rassul Yunussov23-Dec-04 14:06

Rassul Yunussov

23-Dec-04 14:06

My class uses mathematic operation (time critical) and i want the window with progress bar appear, but i couldn't create a dynamic window, i tried this:

CWnd * pWnd = new CWnd;
pWnd->Create("asdf","asdf");
pWnd->ShowWindow(SW_SHOW);

But it doesn't work.
And another question = how to create a dialog window dynamically without using the resources?

Re: How To create a window in MFC dynamically

Maximilien23-Dec-04 14:53

Maximilien

23-Dec-04 14:53

is there a particular reason why you don't want to use the resources ? I would make your life simpler ...

BTW, you can't create a dialog by just using CWnd.

you need to create a DLGTEMPLATE and call InitModalIndirect ...

Maximilien Lincourt
Your Head A Splode - Strong Bad

Re: How To create a window in MFC dynamically

Anonymous23-Dec-04 19:34

Anonymous

23-Dec-04 19:34

like this:
::ShowWindow(::CreateWindow("Button","Button1",WS_CHILD|WS_VISIBLE,10,10,100,50,m_hWnd,NULL,AfxGetApp()->m_hInstance,NULL),SW_NORMAL);

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.