C / C++ / MFC Discussion Boards

Re: Multiple inclusion of header file

ThatsAlok10-May-05 23:21

ThatsAlok

10-May-05 23:21

toxcct wrote:
are these the same ?

Sigh | :sigh:

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

cheers,
Alok Gupta

Where are smart pointers used

Girish60110-May-05 19:37

Girish601

10-May-05 19:37

Hello Group

Can anybody in the group Try to Explain,What are Smart pointers and what are the advantages over the pointers and exactly where are they used frequently???

VC++

Re: Where are smart pointers used

S. Senthil Kumar10-May-05 20:23

S. Senthil Kumar

10-May-05 20:23

Smart pointers can be used wherever you use raw pointers. They basically make sure that every new is paired with a matching delete and that you delete allocated memory only once. Typically, they do this by reference counting.

Regards
Senthil
_____________________________
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Re: Where are smart pointers used

Girish60110-May-05 20:47

Girish601

10-May-05 20:47

First of all very thanks to S.Senthil Kumar for taking time to describe this concept.

But it is bit theoretical can i have some more information on this regarding how to use this concept

VC++

Re: Where are smart pointers used

Aamir Butt10-May-05 21:24

Aamir Butt

10-May-05 21:24

Take a look at CComPtr class in MSDN. This is an example of smart pointers.

"I would luv to change the world, but they wont give me the source code" Frown | :(

My Articles

Re: Where are smart pointers used

toxcct11-May-05 1:09

toxcct

11-May-05 1:09

...or search for std::autoPtr for C++ standard

TOXCCT >>> GEII power
[toxcct][VisualCalc]

convert OpenGL to HPGL?

lxy10-May-05 18:25

lxy

10-May-05 18:25

Is there any open source codes which can convert OpenGL rendering to HPGL format file?

Registerclipboardformat..or setclipboarddata does these functions support unicode for custom formats?

vineet_bhargava10-May-05 18:06

vineet_bhargava

10-May-05 18:06

Hi all,
I am registering a clipboard format as follows

UINT format = Registerclipboardformat(_T("FileName"));
then using the same format for setting the clipboard data

Setclipboarddata(format,hclipboarddata);

Now when i pass the file name to the handle, i could see in the memory location the path name is correct but after the execution of setclipboarddata command and after closing the clipboard when i see on the clipbook viewer, only drive letter is pasted.

Pl. answer to me ?

Thanks..
Vineet
Confused | :confused:

Libraries

DOC Wilson10-May-05 17:50

DOC Wilson

10-May-05 17:50

In VC++ 5.0 through 7.0 creating a static library is no big deal. Any projects created can find the libraries quite easily. Now I need to use a specific library in a VC++.Net environment and am a loss as to how to.

I am a teacher at a community college and basically teach c++ console applications and the texts that I use currently contain a copy of VC++ 6.0 but our classrooms are fixed with VC++.Net

Any help would be helpful.

I am a new member and hope to submit this particular library that provides a sequre method for fetching keyboard data for all primitive types, strings and dates for console applications which obviate the not-so-secure cin.

DOC Confused | :confused:

Re: Libraries

Christian Graus10-May-05 17:55

Christian Graus

10-May-05 17:55

Maybe this will help ?

http://www.functionx.com/vcnet/libraries/staticnet.htm[^]

Christian Graus - Microsoft MVP - C++

enum problem

Ista10-May-05 16:12

Ista

10-May-05 16:12

I have an include fiel enums.h that houses off enums used
enum WordDirection
{
Right = 0,
Down,
Diag_Down,
Diag_Up
};

I have a class 'A'
private:
int _iRow;
int _iCol;
bool _bHighlight;
std::vector<cletter> _arrLetters;
WordDirection _enumDirection;
TCHAR _sWord[16];

now adding the include into the cpp seems fine. but the compile flips in the enum line of the include file and says "error C2011: 'WordDirection' : 'enum' type redefinition"

nick

I'm not an expert yet, but I play one at work. Yeah and here too.

Re: enum problem

Christian Graus10-May-05 16:40

Christian Graus

10-May-05 16:40

your file is being included more than once, so it's trying to create the enum more than once ( I reckon ). If you're using precompiled headers ( stdafx.h ), try including it in there and nowhere else in your project. The other thing is to put an inclusion guard block around your code so it will only include once. I think #pragma once is all you need to do this, at the top of the file.

Christian Graus - Microsoft MVP - C++

Close IE.

Member 46884410-May-05 15:17

Member 468844

10-May-05 15:17

I need to close IE after starting IE with Createprocess. I am using ::PostMessage to try to close IE, but it is not working. I want to use Createprocess to start IE.
LPSTR szAPP = "c:\\progra~1\\intern~1\\iexplore.exe";
(CreateProcess(NULL,szAPP, NULL,NULL,FALSE,0,NULL,NULL,&StartupInfo,&ProcessInfo));
Sleep(10000);
hWnd=FindWindow(_T("IEFrame"), NULL);

::PostMessage(hWnd, WM_CLOSE, NULL, NULL);

Re: Close IE.

Aamir Butt10-May-05 21:27

Aamir Butt

10-May-05 21:27

Why dont u use ExitProcess API to close it.

"I would luv to change the world, but they wont give me the source code" Frown | :(

My Articles

Re: Close IE.

ThatsAlok10-May-05 22:52

ThatsAlok

10-May-05 22:52

ZakAkili wrote:
hWnd=FindWindow(_T("IEFrame"), NULL);

Hi Mr Zak,
have you check for returned hWnd, may be it's NULL?

ZakAkili wrote:
::PostMessage(hWnd, WM_CLOSE, NULL, NULL);

Try WM_QUIT or pass ProcessInfo.hProcess returned from CreateProcess to TerminateProcess to closedown the IE

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

cheers,
Alok Gupta

Re: Close IE.

David Crow11-May-05 3:41

David Crow

11-May-05 3:41

Try:

LPCSTR szAPP = "c:\\progra~1\\intern~1\\iexplore.exe"; 
CreateProcess(NULL,szAPP,NULL,NULL,FALSE,0,NULL,NULL,&StartupInfo,&ProcessInfo));
 
Sleep(10000);
 
TerminateProcess(ProcessInfo.hProcess, 0);

"Ideas are a dime a dozen. People who put them into action are priceless." - Unknown

Re: Close IE.

Member 46884411-May-05 21:32

Member 468844

11-May-05 21:32

Thanks, All of the replys have helped.

Byte conversion?!

Shining200510-May-05 11:54

Shining2005

10-May-05 11:54

Hi Guys.

I was reading through one of Mike's articles on sockets. And I just CANT
seems to wrap my brain around this one:

BYTE* bp = (BYTE*)(&dataLength) + sizeof(dataLength) - cbLeftToReceive;
I got this far:

(Its a Byte)(Called bp) = (Point to Byte)(&WHAT?!?!) + Something?
Okay now I'm lost.. I simply dont get the (&dataLength), now Datalength
is just an int, so what with the (&int) what does it do?

What does the syntax here mean?

Somebody please help me out!

Shine

Re: Byte conversion?!

PJ Arends10-May-05 12:16

PJ Arends

10-May-05 12:16

Mike who?

Which article?

Shining2005 wrote:
BYTE* bp = (BYTE*)(&dataLength) + sizeof(dataLength) - cbLeftToReceive;

BYTE* bp ==> bp is a pointer to a BYTE

(BYTE*)(&dataLength) ==> casting the address of dataLength to a BYTE pointer

+ sizeof(dataLength) ==> advance the BYTE pointer to the byte just past the end of the memory occupied by datalength

- cbLeftToReceive; ==> bring the pointer back cbLeftToReceive bytes

"You're obviously a superstar." - Christian Graus about me - 12 Feb '03

"Obviously ??? You're definitely a superstar!!!" mYkel - 21 Jun '04

Within you lies the power for good - Use it!

Honoured as one of The Most Helpful Members of 2004

convert a DWORD to BYTE[4]

bouli10-May-05 11:27

bouli

10-May-05 11:27

Hello gurus,

I'd like to know how I can convert a DWORD (32 bits) value into a byte array of four bytes (32 bits)?

<br />
DWORD   dwLength=(DWORD) file.GetLength();<br />
BYTE    length[4];<br />

length contains the value dwLength as a 4 bytes array.

Thanks Smile | :)

Best regards.

There is no spoon.

Re: convert a DWORD to BYTE[4]

PJ Arends10-May-05 11:49

PJ Arends

10-May-05 11:49

for (int i = 3; i >= 0; --i)
{
   length[3 - i] = (dwLength & (0xff << (i * 8))) >> (i * 8);
}

"You're obviously a superstar." - Christian Graus about me - 12 Feb '03

"Obviously ??? You're definitely a superstar!!!" mYkel - 21 Jun '04

Within you lies the power for good - Use it!

Honoured as one of The Most Helpful Members of 2004

Re: convert a DWORD to BYTE[4]

Michael Dunn10-May-05 13:02

Michael Dunn

10-May-05 13:02

DWORD dwLength=(DWORD) file.GetLength();
BYTE length[sizeof(DWORD)]; 
 
*(DWORD*) &length[0] = dwLength;

Keep in mind that any code doing anything with the bytes will have to account for the endian type of the CPU.

--Mike--
Visual C++ MVP Cool | :cool:

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Re: convert a DWORD to BYTE[4]

bouli10-May-05 13:10

bouli

10-May-05 13:10

Hi,

Thanks Smile | :)

Actually I've found the following way:

<br />
length[0]=HIBYTE(HIWORD(dwLength));<br />
length[1]=LOBYTE(HIWORD(dwLength));<br />
length[2]=HIBYTE(LOWORD(dwLength));<br />
length[3]=LOBYTE(LOWORD(dwLength));<br />

which also works Smile | :)

There is no spoon.

Re: convert a DWORD to BYTE[4]

Mike_V10-May-05 13:30

Mike_V

10-May-05 13:30

Or how about:

BYTE *pLength = (BYTE*)dwLength;

pLength[0] will equal the low byte (assuming an intel machine)

What do you need this for?

Re: convert a DWORD to BYTE[4]

Michael Dunn10-May-05 15:27

Michael Dunn

10-May-05 15:27

It works, but not the same way as my code in my earlier post. Yours forces big-endian order. Which isn't wrong per se, it's just something to be aware of. Don't try to write that byte array out to a file and read it back in as a DWORD, for example.

--Mike--
Visual C++ MVP Cool | :cool:

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