C / C++ / MFC Discussion Boards

Richard Andrew x644-Nov-07 8:56

4-Nov-07 8:56

I am trying to use the Win32 debugging functions.

The problem arises that the target process always dies when I detach the debugger with "DebugActiveProcessStop()".

Even if I previously call "DebugSetProcessKillOnExit( FALSE )", the target process still exits.

Does anyone have any experience with these functions?

Hide Window before it's creation

vikrant kpr4-Nov-07 6:59

vikrant kpr

4-Nov-07 6:59

Hey Friends

I am trying to run an exe which creates a window.
Now i do not want the window to be visible.
Is there any way to do it?

::ShellExecute(0,"Open","myapp.exe",0,0,SW_HIDE);

even using above it displays the window & does not hides it

Regards

Re: Hide Window before it's creation

Peter Weyzen4-Nov-07 7:19

Peter Weyzen

4-Nov-07 7:19

Ultimately, the app being started has control of whether it shows or hides.

Look at your startup code... CWinApp has a var called m_nCmdShow which contains the intended app startup (your SW_HIDE) -- it's up to you to use it.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~<br />
Peter Weyzen<br />
Staff Engineer<br />
<A HREF="http://www.soonr.com">SoonR Inc -- PC Power delivered to your phone</A>

Re: Hide Window before it's creation

Neo Andreson4-Nov-07 15:43

Neo Andreson

4-Nov-07 15:43

Get the Handle of tht window and hide it using ShowWindow(FALSE)..
ThankXXXXXXXXXXxx

calling .net dll from vs6 c++

BoscoBill4-Nov-07 6:28

BoscoBill

4-Nov-07 6:28

Hi.
I need to call a .net dll from my (unmanaged) vs6 C++ project.
Has anyone done this and could you show me how?
Thanks.

Re: calling .net dll from vs6 c++

Peter Weyzen4-Nov-07 7:12

Peter Weyzen

4-Nov-07 7:12

See Here[^]

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~<br />
Peter Weyzen<br />
Staff Engineer<br />
<A HREF="http://www.soonr.com">SoonR Inc -- PC Power delivered to your phone</A>

Re: calling .net dll from vs6 c++

BoscoBill4-Nov-07 7:34

BoscoBill

4-Nov-07 7:34

Thanks, Peter.
But this approach seems a bit torturous and involves a lot of overhead.
Can't imagine performance would be too good.
I was looking for a simpler solution that some of you have used in a production environment.

Re: calling .net dll from vs6 c++

Mark Salsbery5-Nov-07 5:48

Mark Salsbery

5-Nov-07 5:48

BoscoBill wrote:
this approach seems a bit torturous and involves a lot of overhead.

You don't have much choice.

Switch to VS .NET or VS 2005+ and it will be much easier, since you'll have
managed support built in to the C++ language.

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Re: calling .net dll from vs6 c++

BoscoBill5-Nov-07 6:37

BoscoBill

5-Nov-07 6:37

Has anyone successfully used the Regasm approach in production?
That seems like it may be workable.

Re: calling .net dll from vs6 c++

Mark Salsbery5-Nov-07 7:02

Mark Salsbery

5-Nov-07 7:02

BoscoBill wrote:
Has anyone successfully used the Regasm approach in production?

I have no idea. It's still a viable solution, especially if you're good with COM Smile | :)

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Query regarding MFC application

Chirag_kalra4-Nov-07 5:36

Chirag_kalra

4-Nov-07 5:36

Hi
I'm facing some problem in standard MFC application. In my application, I'm able to run only 3 insatnces of my application simultaneously.That is, i'm able to open only three login screens at the same time, but I dont want this limitaton. I'm currently working in Windows XP. However, when I ran my application in Windows NT, only 4 instances can ber run at a time. When I tried to open it fourth time in Windows XP, it gets crashed at the following line of code.

//winfrm.cpp

BOOL CFrameWnd::Create(LPCTSTR lpszClassName,
LPCTSTR lpszWindowName,
DWORD dwStyle,
const RECT& rect,
CWnd* pParentWnd,
LPCTSTR lpszMenuName,
DWORD dwExStyle,
CCreateContext* pContext)
{
HMENU hMenu = NULL;
if (lpszMenuName != NULL)
{
// load in a menu that will get destroyed when window gets destroyed
HINSTANCE hInst = AfxFindResourceHandle(lpszMenuName, RT_MENU);
if ((hMenu = ::LoadMenu(hInst, lpszMenuName)) == NULL)
{
TRACE(traceAppMsg, 0, "Warning: failed to load menu for CFrameWnd.\n");
PostNcDestroy(); // perhaps delete the C++ object
return FALSE;
}}
m_strTitle = lpszWindowName; // save title for later

if (!CreateEx(dwExStyle, lpszClassName, lpszWindowName, dwStyle,
rect.left, rect.top, rect.right - rect.left, rect.bottom - rect.top,
pParentWnd->GetSafeHwnd(), hMenu, (LPVOID)pContext))
{
TRACE(traceAppMsg, 0, "Warning: failed to create CFrameWnd.\n");
if (hMenu != NULL)
DestroyMenu(hMenu);
return FALSE;
}

return TRUE;
}

Can anybody please advise on this?

Chirag Kalra

Chirag Kalra

MoveFileEx fails

Royce Fickling4-Nov-07 5:34

Royce Fickling

4-Nov-07 5:34

Hi,

I am trying to use the WinAPI function MoveFileEx to move an entire folder, but can't get the formats of the paths correct. Are trailing backslashes required on either or both paths? Are *.* required? I think I have tried every conceivable combination. Can someone please tell me what I am doing wrong?

Thanks
Confused | :confused:

Re: MoveFileEx fails

Nelek4-Nov-07 21:59

Nelek

4-Nov-07 21:59

I think it will be better if you stablish the path, and then you iterate with the individual file names.

The backslashes should be needed in the string,

CString szFile1 = "C:\\MyFolder\\MyFile1.ext"
CString szFile2 = "C:\\MyFolder\\MyFile2.ext"
...

And I mean:

CString szPath = "C:\\MyFolder\\";
use FindFirstFile (...)
while (FindNextFile (...) can be used)
Get the name and move the file

Greetings.

--------
M.D.V.

If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?

Help me to understand what I'm saying, and I'll explain it better to you

Wink | ;)

plzzz Hellppp meeeee exercise for tomorroww

eerrikkaa4-Nov-07 2:46

eerrikkaa

4-Nov-07 2:46

plz help me to complation this code :

#include<iostream>
using namespace ::std;

class calculator
{
private :
int x , y ,z

public :

}

Re: plzzz Hellppp meeeee exercise for tomorroww

David Crow4-Nov-07 2:48

David Crow

4-Nov-07 2:48

eerrikkaa wrote:
}

There's your hint.

"Normal is getting dressed in clothes that you buy for work and driving through traffic in a car that you are still paying for, in order to get to the job you need to pay for the clothes and the car and the house you leave vacant all day so you can afford to live in it." - Ellen Goodman

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Re: plzzz Hellppp meeeee exercise for tomorroww

Hamid_RT4-Nov-07 3:07

Hamid_RT

4-Nov-07 3:07

Re: plzzz Hellppp meeeee exercise for tomorroww

Stephen Hewitt4-Nov-07 3:19

Stephen Hewitt

4-Nov-07 3:19

There should be be semicolons as shown below:

class calculator
{
private:
int x, y, z;
 
public:
};

Steve

Re: plzzz Hellppp meeeee exercise for tomorroww

ThatsAlok4-Nov-07 18:54

ThatsAlok

4-Nov-07 18:54

eerrikkaa wrote:
#include
using namespace ::std;

class calculator
{
private :
int x , y ,z

public :

}

The answer will help you to compile the code., but nothing will run.

you have to include void main() in your program to see something running.

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
Never mind - my own stupidity is the source of every "problem" - Mixture

cheers,
Alok Gupta
VC Forum Q&A :- I/IV
Support CRY- Child Relief and You

SMTP mail server

bigdenny2004-Nov-07 1:04

bigdenny200

4-Nov-07 1:04

Hey all,

I asked this question before, but (surprisingly) did'nt get any replies.
Let me rephrase it in a bit different way..

I want to implement a SMTP server in C++, but dont know where to start from.
I looked up in internet for any tutorials or any already existing SMTP server classes,
but couldnt find any of them. The only thing that I found were classes for SMTP
clients, i.e. for sending emails, but that is not what I need as you can see.

I would really appreciate any helpful comments regarding this matter.

Thanks.

which way is more efficient to check bit value

George_George4-Nov-07 1:02

George_George

4-Nov-07 1:02

Hello everyone,

I have a long array (char*) and I need to check which bit is the first bit whose value is 1.

I have two ways to implement,

1. Iterate each byte, then iterate each bit in each byte one by one;
2. Iterate each byte, and check whether the value of the byte itself is non-zero, if yes, then iterate each bit in the byte to find which bit is the first bit which is set to 1, or else skip this byte and continue to iterate next byte.

I think (2) is always faster, right? But I do not know why (2) is faster since it is just my personal estimation without any concrete basis analysis.

thanks in advance,
George

Re: which way is more efficient to check bit value

David Crow4-Nov-07 2:48

David Crow

4-Nov-07 2:48

George_George wrote:
I think (2) is always faster, right?

Only because it skips bytes with a value of 0. If your input set had no such values, there would be no difference.

Re: which way is more efficient to check bit value

George_George4-Nov-07 18:15

George_George

4-Nov-07 18:15

Thanks DavidCrow,

I agree. If the character buffer array does not have a long heading 0-value bytes, there should not be any differences.

regards,
George

Re: which way is more efficient to check bit value

C^hris L^osinger4-Nov-07 5:47

C^hris L^osinger

4-Nov-07 5:47

2 will be much faster, for data which is likely to have a lot of 0 bytes.

and, as long as you're checking for 0, you might as well test for 255 (all bit set), too.

and, that brings up a question: is there a way to test all the other bit patterns a byte can have without having to shift and mask each one ?

the answer is Yes.

int look_up_table[256];
look_up_table[0] = -1; // no bits set
look_up_table[1] = 0; // first bit set is bit 0
look_up_table[2] = 1; // first bit set is bit 1
look_up_table[3] = 1; // first bit set is bit 1
look_up_table[4] = 2; // first bit set is bit 2
look_up_table[5] = 2; // first bit set is bit 2
look_up_table[6] = 2; // first bit set is bit 2
look_up_table[7] = 2; // first bit set is bit 2
look_up_table[8] = 3; // first bit set is bit 3
...
look_up_table[255] = 7; // first bit set is bit 7

then, to see which bit is set:

int first_bit_set = look_up_table[byte_to_test];

that will outperform any shift-and-mask algorithm probably by an order f magnitude.

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Re: which way is more efficient to check bit value

George_George4-Nov-07 18:26

George_George

4-Nov-07 18:26

Thanks Chris Losinger,

Looks like you have smarter ways to solve my question. I am always interested to learn better ideas. I have studied your idea for a while and I do not quite understand why you have two value 1? four value 2?

Especially I do not quite understand this,

int first_bit_set = look_up_table[byte_to_test];

Could you show me some samples about how it works? Sorry for my stupid and confusion. Smile | :)

Chris Losinger wrote:
int look_up_table[256];
look_up_table[0] = -1; // no bits set
look_up_table[1] = 0; // first bit set is bit 0
look_up_table[2] = 1; // first bit set is bit 1
look_up_table[3] = 1; // first bit set is bit 1
look_up_table[4] = 2; // first bit set is bit 2
look_up_table[5] = 2; // first bit set is bit 2
look_up_table[6] = 2; // first bit set is bit 2
look_up_table[7] = 2; // first bit set is bit 2
look_up_table[8] = 3; // first bit set is bit 3

regards,
George

Re: which way is more efficient to check bit value

C^hris L^osinger5-Nov-07 0:58

C^hris L^osinger

5-Nov-07 0:58

binary 0 = 00000000
binary 1 = 00000001 : first bit set is bit 0
binary 2 = 00000010 : first bit set is bit 1
binary 3 = 00000011 : first bit set is bit 1
binary 4 = 00000100 : first bit set is bit 2
binary 5 = 00000101
binary 6 = 00000110
binary 7 = 00000111
binary 8 = 00001000 : first bit set is bit 3
binary 9 = 00001001 : first bit set is bit 3
binary 10= 00001010 : first bit set is bit 3

etc.,

up to 255 = 11111111 : first bit set is bit 7

so, look_up_table is an array of values that track the first bit set for each value a BYTE can hold.

if you want to know the first bit set in 10, for example:

int first_bit_set = look_up_table[10];

that gives you...3

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