Re: C++ class definitions - C / C++ / MFC Discussion Boards

Re: C++ class definitions

David Crow28-Aug-07 2:36

David Crow

28-Aug-07 2:36

baerten wrote:
Is it possible that more than one declaration of public or protected blocks makes
internal errors?

No, it makes no difference. But, by simply moving member variables around, it's highly possible that you simply moved the problem, too.

"A good athlete is the result of a good and worthy opponent." - David Crow

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

Re: C++ class definitions

baerten28-Aug-07 2:44

baerten

28-Aug-07 2:44

Thanks for help

Do you think there is a memory fault between the start of the class and my char*-variable?

At the time where i had a similar problem, i moved also the declared (and corrupt) variable line by
line higher, to find at which place the error occurs.
But there was no special pointer which could be allocated with a buggy class which could provoque
f.ex. a buffer overrun

Re: C++ class definitions

David Crow28-Aug-07 2:48

David Crow

28-Aug-07 2:48

baerten wrote:
Do you think there is a memory fault between the start of the class and my char*-variable?

There's nothing wrong with the class declaration. You may be using it incorrectly, however.

"A good athlete is the result of a good and worthy opponent." - David Crow

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

Re: C++ class definitions

Russell^'28-Aug-07 3:06

Russell^'

28-Aug-07 3:06

Some MACRO sometimes create strange problems!

This is the definition of DECLARE_MESSAGE_MAP():

<code>#define DECLARE_MESSAGE_MAP() \
private: \
	static const AFX_MSGMAP_ENTRY _messageEntries[]; \
protected: \
	static const AFX_MSGMAP messageMap; \
	virtual const AFX_MSGMAP* GetMessageMap() const; \</code>

So if:

...
public:
DECLARE_MESSAGE_MAP()
UINT m_IsThisAPublicMemberAsIWant;
...

then m_IsThisAPublicMemberAsIWant;is .... protected!!!!!
Cry | :((

Hope helps Wink | ;)

Russell

Re: C++ class definitions

baerten28-Aug-07 3:16

baerten

28-Aug-07 3:16

Nice Macro LOL

I'll test if i move the variable before and after macros

Thanks for the suggestion Smile | :)

Re: C++ class definitions

Russell^'28-Aug-07 3:28

Russell^'

28-Aug-07 3:28

baerten wrote:
Nice Macro LOL

Yes! When I found this problem some years ago, as the cause of the bug in my project I was too happy: I closed my PC and went to the beach! Laugh | :laugh:

baerten wrote:
Thanks for the suggestion

You are wellcome Rose | [Rose]

Russell

Re: C++ class definitions

Maxwell Chen28-Aug-07 4:36

Maxwell Chen

28-Aug-07 4:36

I always make my own sections to separate from Wizard generated code. Such as:

// CBeeDlg dialog
class CBeeDlg : public CDialog
{
// Construction
public:
	CBeeDlg(CWnd* pParent = NULL);	// standard constructor

// Dialog Data
	enum { IDD = IDD_BEE_DIALOG };

protected:
	virtual void DoDataExchange(CDataExchange* pDX);	// DDX/DDV support
// Implementation
protected:
	// Generated message map functions
	virtual BOOL OnInitDialog();
	afx_msg void OnSysCommand(UINT nID, LPARAM lParam);
	afx_msg void OnPaint();
	afx_msg HCURSOR OnQueryDragIcon();
	DECLARE_MESSAGE_MAP()
 
 
 
// My own code begins below...
protected:
	void InitFont_();
	bool RefreshReaders_();
	void FreeResource_();
	void SetExitFlag_() { m_bExit = true; }
	void InitFrameParam_();
public:
	void LogMsg(CString sTxt, bool bDbgOnly = false);
	void LogErrorMsg();
};

Maxwell Chen

Re: C++ class definitions

Russell^'28-Aug-07 7:16

Russell^'

28-Aug-07 7:16

I think that this is one of the best ways, the code is also more clear and readable.
Wink | ;)

Russell

Re: C++ class definitions

Michael Dunn28-Aug-07 8:04

Michael Dunn

28-Aug-07 8:04

Moving members also changes how the class is laid out in memory. So if you have a bug in how you access member data, it may be hidden or exposed as you change how the members are arranged in memory.

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

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Redistributing a command-line program made with VC++ 2005?

Maxwell Chen28-Aug-07 1:31

Maxwell Chen

28-Aug-07 1:31

Even though there is the topic in MSDN for Side-by-Side and manifest stuffs, I still don't get the correct steps to redistribute a command-line program to another computer.

I use some functions and types of the standard C++ library and some win32 APIs in the program without MFC/ATL. I don't find any project option for statically link to CRT libraries.

The program is to be called by other program, so I don't want to have users run "VCRedist_x86.exe". I hope to keep it simple!

What would be the simplest way to redistribute this program?

Thanks!

Maxwell Chen

Re: Redistributing a command-line program made with VC++ 2005?

jhwurmbach28-Aug-07 1:48

jhwurmbach

28-Aug-07 1:48

Maxwell Chen wrote:
I don't find any project option for statically link to CRT libraries.

Project properties - C/C++ - Code Generation - Runtime Library = something without DLL.

Maxwell Chen wrote:
The program is to be called by other program, so I don't want to have users run "VCRedist_x86.exe".

But users only have to run this once. This would probably been done at installation time.
Or you have to force the users on computers without these files to download and install it once.

Maxwell Chen wrote:
What would be the simplest way to redistribute this program?

A Setup.Exe made with the VC-internal setup-functionality or free installers like NSIS[^] or Inno Setup[^].

Though I speak with the tongues of men and of angels, and have not money, I am become as a sounding brass, or a tinkling cymbal.
George Orwell, "Keep the Aspidistra Flying", Opening words

Re: Redistributing a command-line program made with VC++ 2005?

Maxwell Chen28-Aug-07 2:03

Maxwell Chen

28-Aug-07 2:03

jhwurmbach wrote:
Project properties - C/C++ - Code Generation - Runtime Library = something without DLL.

Thank you very much for your great help.
I changed from /MD to /MT, and it works!

jhwurmbach wrote:
A Setup.Exe made with the VC-internal setup-functionality or free installers like NSIS[^] or Inno Setup[^].

This program is to be called by an uninstaller to manipulate the registry. So it wouldn't fit for making a setup for this program though. Blush | :O

Maxwell Chen

Re: Redistributing a command-line program made with VC++ 2005?

jhwurmbach28-Aug-07 2:05

jhwurmbach

28-Aug-07 2:05

Maxwell Chen wrote:
This program is to be called by an uninstaller to manipulate the registry. So it wouldn't fit for making a setup for this program though.

But you could add it to the requirements at install time - then it would be there (and not be uninstalled, AFAIK) at uninstall time.

Though I speak with the tongues of men and of angels, and have not money, I am become as a sounding brass, or a tinkling cymbal.
George Orwell, "Keep the Aspidistra Flying", Opening words

Writing a C++ code to print a file

barun_iit28-Aug-07 1:29

barun_iit

28-Aug-07 1:29

Hi,
I want to write a C++ program to print a file in user space. But i don't know how to access the printer.

Please help me.
With thanks in advance,
barun

barun

Re: Writing a C++ code to print a file

Nishad S28-Aug-07 1:39

Nishad S

28-Aug-07 1:39

If you just want to print the file in text format, what about using "stdprn"?

- NS -

Re: Writing a C++ code to print a file

chandu00428-Aug-07 1:42

chandu004

28-Aug-07 1:42

USE system("print filename");

Re: Writing a C++ code to print a file

barun_iit28-Aug-07 18:10

barun_iit

28-Aug-07 18:10

Hi Using system is one of the way to handle this, but this method is not generic for other types of devices like scanner or USB stick etc.

We know that any device should be opened then read/write and finally to be closed. Can we write a C++ code to open any device and read/ write into it (e.g. printer) ?

With thanks in advance.
barun

barun

Identifying a corrupt exe

vipin_nvk28-Aug-07 1:15

vipin_nvk

28-Aug-07 1:15

Hello

My code copies an exe onto a USB flash drive using normal File copy functions, however it is quite possible that the USB flash drive might get disconnected during file copy and may not be copied properly (hence gets corrupted) So, when the user plugs in the USB flash drive next time he / she wont be able to use it. Is it possible programatically to identify a corrupted exe once the exe has been copied onto the USB flash drive ?

Thanx

Re: Identifying a corrupt exe

jhwurmbach28-Aug-07 1:38

jhwurmbach

28-Aug-07 1:38

Checksumming (e.g. MD5). Tools like MD5sum are readyly available in the internet.
But the corrupted exe will very properly not start, so it can't check itself.

Though I speak with the tongues of men and of angels, and have not money, I am become as a sounding brass, or a tinkling cymbal.
George Orwell, "Keep the Aspidistra Flying", Opening words

Re: Identifying a corrupt exe

kasturi_haribabu28-Aug-07 1:42

kasturi_haribabu

28-Aug-07 1:42

Although there is no Direct way to do this, letme specify some alternatives.

1. calculate the Check sum of the File before you save and validate it after your file copy operation is complete. (Less Error prone but effective)

2.Verify the Size of the file copied.

haribabu

Inside ntdll.dll

Waldermort28-Aug-07 1:04

Waldermort

28-Aug-07 1:04

Can anybody tell me why I'm unable to step inside ntdll with the MS debugger?

I am trying to hook NtCreateSection and replace the section with my own, but I'm getting access violation return codes. So I try stepping into the mthod in order to see what is going on, but I immediatly land on a JUMP instruction and get thrown back out. The code then fails with an "unable to read this address" pop-up. Stepping over the call causes no problems.

Anyway, I have a section created from a file with the PAGE_READONLY flag set, I tried changing this to PAGE_WRITECOPY which succeeds but I'm still unable to map the section. ( No access rights ). But the section is created with ALL_ACCESS_RIGHTS.

Any ideas?

Re: Inside ntdll.dll

Stephen Hewitt28-Aug-07 14:49

Stephen Hewitt

28-Aug-07 14:49

You can, but there won't be much to see as most of it just contains code to transition to kernel mode (where a user mode debugger can't follow).

Steve

Re: Inside ntdll.dll

Waldermort28-Aug-07 14:55

Waldermort

28-Aug-07 14:55

Yeah, I figured that out after decompiling the dll. I never found the solution to the problem though, I have a feeling the DACL was being set high while the section was being passed between user/kernel modes, preventing me access to it.

Templates

Russell^'28-Aug-07 0:16

Russell^'

28-Aug-07 0:16

Is there a sintax error? Confused | :confused:

template<typename MYTYPE> class CMyTemplate{
   ....
};

template<typename MYTYPE> class CFamily{
private:
	CMyTemplate< CMyTemplate<MYTYPE> > m_Member;:mad:
public:
   ....
};

VS tells:
Missing ";" before "<" where I delcare m_Member
OMG | :OMG:

Russell

Re: Templates

Russell^'28-Aug-07 0:52

Russell^'

28-Aug-07 0:52

After 4 painful days ... got it!
(to many #include in the project ... Blush | :O

)
tnx anyway Big Grin | :-D

Russell

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