Re: Linker problem - C / C++ / MFC Discussion Boards

FarPointer22-Dec-05 1:55

22-Dec-05 1:55

Hi All ,
i have some data(raw data) and i want to save those as xml in to hardisk , how do i do it in vc++,can any one help me sending the link or give an idea .

Regards
Farpointer

Re: Writing xml

Sebastian Schneider22-Dec-05 2:18

Sebastian Schneider

22-Dec-05 2:18

I suggest that you read up on MSXML. You still need to read the "raw" data yourself, though - either by reading it into a datastructure or - if its "human readable" - by parsing it into one.

MSXML provides loads of functions to read and write XML files.

There are some other XML libs out there that might be more advanced or sophisticated, but until now, I only had to read a few setting from a file that held some configuration options.

MSXML should be available on most win-boxes, though I am not sure about the relation between windows-version/SP and msxml-release.

With VC7, you could also use the tools provided by the .NET-Runtime, which handles XML pretty well, but would require the .NET Redistributable to be installed on the target system.

If you need further information on XML per se: I think a saw a free EBook on the O'Reilly-Website dealing with XML in general.

Cheers,
Sebastian

--
Contra vim mortem non est medicamen in hortem.

Re: Wrinting as xml

ThatsAlok22-Dec-05 2:20

ThatsAlok

22-Dec-05 2:20

farpointer wrote:
one help me sending the link or give an idea

http://www.codeproject.com/soap/markupclass.asp[^]

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

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

Linker problem

ThatsAlok22-Dec-05 1:44

ThatsAlok

22-Dec-05 1:44

HI EveryBody,
I am facing a problem... i am not able to compile this code.. could any body suggest me work around for following code :-

#include <iostream.h>
typedef int wxCoord ;

template <class T>
class CTextDropTarget
{
private:
     bool (T::*m_pt2CallbackFunc)(wxCoord x, wxCoord y);
public:
     CTextDropTarget(bool (T::*pt2Func)(wxCoord x, wxCoord y));
     virtual ~CTextDropTarget(void);
     virtual bool OnDropText(wxCoord x, wxCoord y);

};

template <class T>
CTextDropTarget<T>::CTextDropTarget(bool ( T::*pt2Func)(wxCoord x, wxCoord y))
{
	m_pt2CallbackFunc=pt2Func;
	
}


template <class T>
CTextDropTarget<T::~CTextDropTarget(void)
{
}


template <class T>
bool CTextDropTarget<T>::OnDropText(wxCoord x, wxCoord y)
{
     return false;
}


class CSACAddressListCtrl
{
	public:
     CTextDropTarget<CSACAddressListCtrl> *m_pDropTarget;
    static  bool OnTextDropTarget(wxCoord x, wxCoord y)
	{
		return x+y;
	}
};

 
void main()
{
    CTextDropTarget* m_pDropTarget = new CTextDropTarget<CSACAddressListCtrl>( &CSACAddressListCtrl::OnTextDropTarget);
 
}

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

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

-- modified at 8:01 Thursday 22nd December, 2005

Re: Linker problem

toxcct22-Dec-05 2:18

toxcct

22-Dec-05 2:18

dear alok what does the compiler or the linker say ?

TOXCCT >>> GEII power
[toxcct][VisualCalc 2.20][VisualCalc 3.0]

Re: Linker problem

ThatsAlok22-Dec-05 2:22

ThatsAlok

22-Dec-05 2:22

toxcct wrote:
dear alok what does the compiler or the linker say ?

Ohh Sorry!, here is what compiler/linker says Smile | :)

D:\Alok\Test Project\cpp\11.cpp(70) : warning C4800: 'int' : forcing value to bool 'true' or 'false' (performance warning)

D:\Alok\Test Project\cpp\11.cpp(78) : error C2664: '__thiscall 
CTextDropTarget<class CSACAddressListCtrl>::CTextDropTarget<class 
CSACAddressListCtrl>(bool (__thiscall CSACAddressListCtrl::*)
(int,int))' : 
cannot convert parameter 1 from 'bool (__cdecl *)(int,int)' to 'bool (__thiscall CSACAddressListCtrl::*)(int,int)'
There is no context in which this conversion is possible
Error executing cl.exe.

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

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

-- modified at 8:23 Thursday 22nd December, 2005

Re: Linker problem

David Crow22-Dec-05 2:38

David Crow

22-Dec-05 2:38

ThatsAlok wrote:
D:\Alok\Test Project\cpp\11.cpp(70)

I don't see 70 lines in your code snippet. Confused | :confused:

"Take only what you need and leave the land as you found it." - Native American Proverb

Re: Linker problem

ThatsAlok22-Dec-05 2:40

ThatsAlok

22-Dec-05 2:40

DavidCrow wrote:
I don't see 70 lines in your code snippet.

Hai Sir,
while posting code.. I removed blank lines from source code.. actually problem is at this line :-

CTextDropTarget* m_pDropTarget = 
new CTextDropTarget<CSACAddressListCtrl>
( &CSACAddressListCtrl::OnTextDropTarget);

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

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

Re: Linker problem

toxcct22-Dec-05 2:40

toxcct

22-Dec-05 2:40

this is a compiler error (not a linker one.

it says that it cannot convert a __cdecl function pointer to a __thiscall one...
i don't know why it does happen, but you might try to call a global function thinking it is a class member.

TOXCCT >>> GEII power
[toxcct][VisualCalc 2.20][VisualCalc 3.0]

Re: Linker problem

ThatsAlok22-Dec-05 2:42

ThatsAlok

22-Dec-05 2:42

toxcct wrote:
i don't know why it does happen, but you might try to call a global function thinking it is a class member.

Any other solution!

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

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

Re: Linker problem

Cedric Moonen22-Dec-05 2:54

Cedric Moonen

22-Dec-05 2:54

toxcct wrote:
i don't know why it does happen

It is because the prototypes for a normal function (__cdecl) and a member function of a class (__thiscall) are different. For the class function, an extra parameter is passed implicitely which is the this parameter (in order for the function to be able to know which instance of the class called her).

Two solution: change the function to a global function (which is not really appropriate) or change it into a static function. A static function (member of a class) is shared among all instances of that class thus, it doesn't require the implicit this parameter but this also implies that you cannot use non-static members (functions or variables) of the class.

Re: Linker problem

Cedric Moonen22-Dec-05 3:00

Cedric Moonen

22-Dec-05 3:00

Remove the static keyword from the OnTextDropTarget function in your CSACAddressListCtrl class.

The constructor of your template class expects a member function of your class (template) thus if this function is static, the prototype is different ( see my other post in response to toxcct).

Re: Linker problem

ThatsAlok22-Dec-05 18:59

ThatsAlok

22-Dec-05 18:59

Cedric Moonen wrote:
Remove the static keyword from the OnTextDropTarget function in your CSACAddressListCtrl class.

Hai Cedric,
I know that way... but i am looking for templatized solution... which i believe not that simple Smile | :)

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

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

Re: Linker problem

Eytukan22-Dec-05 3:19

Eytukan

22-Dec-05 3:19

a question from ALOK??? Unsure | :~

, that should be a real question. Smile | :)

"But your mind is very complex, very tricky. It makes simple things complicated. -- that's its work. And for centuries it has been trained for only one thing: to make things so complicated that your life becomes impossible."- Osho

<marquee scrollamount="1" scrolldelay="1" direction="up" height="10" step="1">
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Re: Linker problem

ThatsAlok22-Dec-05 19:37

ThatsAlok

22-Dec-05 19:37

VivekuniQ wrote:
a question from ALOK???, that should be a real question

Why! Isn't I am human being... I have problems too..

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

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

Re: Linker problem

ThatsAlok22-Dec-05 21:39

ThatsAlok

22-Dec-05 21:39

VivekuniQ wrote:
that should be a real question.

and real answer :-
http://www.codeproject.com/script/comments/forums.asp?msg=1315456&forumid=1647#xx1315456xx[^]

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

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

Re: Linker problem

S. Senthil Kumar22-Dec-05 3:48

S. Senthil Kumar

22-Dec-05 3:48

Basically what Cedric said. For static functions, the declaration of the pointer to the function does include the classname. So if you had

bool (*m_pt2CallbackFunc)(wxCoord x, wxCoord y);

instead of

bool (T::*m_pt2CallbackFunc)(wxCoord x, wxCoord y);

your code would have worked. If you do have the classname prefixed, you can only pass non-static member functions of T.

Regards
Senthil
_____________________________
My Blog | My Articles | WinMacro

Re: Linker problem

ThatsAlok22-Dec-05 18:49

ThatsAlok

22-Dec-05 18:49

S. Senthil Kumar wrote:
Basically what Cedric said. For static functions, the declaration of the pointer to the function does include the classname. So if you had

bool (*m_pt2CallbackFunc)(wxCoord x, wxCoord y);

I know about that method... but I am trying to use templates with function pointer! any suggestion

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

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

Re: Linker problem

S. Senthil Kumar22-Dec-05 19:12

S. Senthil Kumar

22-Dec-05 19:12

I don't get it. Are you saying you want to solve the problem without changing the function pointer signature and the static modifier?

The problem you have is not in any way related to templates, it's because you are passing a wrong function to be assigned to a function pointer. Take this class for example.

class X
{
public:
	static void Y(bool x)
	{
	}
};

Now if the function pointer is typedeffed to typedef void (*Func)(bool x);, you can do Func f = &X::Y;. However, if the function pointer is typedeffed to typedef void (*X::Func)(bool x);, you can't do Func f = &X::Y;. That's because X::Func implies that the first (or last) parameter of the function pointed to by Func is the "this" pointer (thiscall calling convention). Because static functions don't take the "this" pointer as a parameter, the compiler will reject Func f = &X::Y;.

The solution is to remove the static modifier from Y, or, change the typedef by removing the X:: prefix.

Regards
Senthil
_____________________________
My Blog | My Articles | WinMacro

Re: Linker problem

ThatsAlok22-Dec-05 19:43

ThatsAlok

22-Dec-05 19:43

S. Senthil Kumar wrote:
The solution is to remove the static modifier from Y, or, change the typedef by removing the X:: prefix.

Hai Senthil,
Thanks for your time... I have found the solution, my friend soon post the code here !

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

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV

-- modified at 1:47 Friday 23rd December, 2005

Re: Linker problem

ThatsAlok22-Dec-05 21:33

ThatsAlok

22-Dec-05 21:33

here is the solution :-

#include <iostream>
#include <string>
using namespace std;
typedef int wxCoord;
typedef string wxString;

template <class T>
class CTextDropTarget
{
private:

typedef bool (T::*pt2Func)(wxCoord, wxCoord, const wxString&);
T* m_pParent;
pt2Func m_pt2CallbackFunc;

public:
CTextDropTarget(T* pParent, pt2Func pt2CallbackFunc);
virtual ~CTextDropTarget(void);
virtual bool OnDropText(wxCoord x, wxCoord y, const wxString& data);

};

template <class T>
CTextDropTarget<T>::CTextDropTarget(T* pParent, pt2Func pt2CallbackFunc)
: m_pParent(pParent)
, m_pt2CallbackFunc(pt2CallbackFunc)

{}

template <class T>
CTextDropTarget<T>::~CTextDropTarget(void)
{}

template <class T>
bool CTextDropTarget<T>::OnDropText(wxCoord x, wxCoord y, const wxString& data)
{
return (m_pParent->*m_pt2CallbackFunc)(x, y, data);
}

class CMyListCtrl
{
private:
CTextDropTarget<CMyListCtrl > *m_pDropTarget;
public:
CMyListCtrl()
{
m_pDropTarget = new CTextDropTarget< CMyListCtrl >(this, CMyListCtrl::OnTextDropTarget);
}

bool OnTextDropTarget(wxCoord x, wxCoord y, const wxString& data)
{
std::cout << data;
return true;
}
};

void main()
{
CMyListCtrl a;
}

<p align='right'> <small>"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow</small></p>
cheers,
<a target=_blank href="http://www.thatsalok.com"> Alok Gupta </a>
VC Forum Q&A :- <a href="http://www.codeproject.com/tips/cppfaq10dec04-23jan05.asp" target=_blank>I</a>/ <a href="http://www.codeproject.com/useritems/cppfaq25apr8jun.asp" target=_blank>IV</a>

COM in C language.

pc_dev22-Dec-05 1:07

pc_dev

22-Dec-05 1:07

I have an older program written in C laguage. can i add a COM component to it, so that i may use its funtionality.
any sample is highly appreciated.

Re: COM in C language.

Cedric Moonen22-Dec-05 1:53

Cedric Moonen

22-Dec-05 1:53

Is it C or C++ ? If it's C++, does it use the WIN32 API ?

Re: COM in C language.

pc_dev22-Dec-05 19:51

pc_dev

22-Dec-05 19:51

I am using simple c language no c++, currently there is no win api's, but in the future there may or may not use api's.

Re: COM in C language.

Andy Moore22-Dec-05 6:44

Andy Moore

22-Dec-05 6:44

Yes you can. Here is an example calling Microsoft's DirectX diagnostic utilities. The
interface IDxDiagProvider is a C++ class or a C structure. Here it is a C structure and the V-Table methods are called through the lpVtbl structure of function pointers. Also the pointer to the object it self is passed into the first parameter since there is no "this" pointer.

HRESULT hr;<br />
	BOOL bCleanupCOM = FALSE;<br />
	IDxDiagProvider* pDxDiagProvider = NULL;<br />
	DXDIAG_INIT_PARAMS dxDiagInitParams;<br />
	VARIANT var;<br />
	char strDestination[10];<br />
<br />
	hr = CoInitialize( NULL );<br />
<br />
	bCleanupCOM = SUCCEEDED( hr );<br />
<br />
	hr = CoCreateInstance( &CLSID_DxDiagProvider, NULL, CLSCTX_INPROC_SERVER,<br />
		                   &IID_IDxDiagProvider, (void**)&pDxDiagProvider );<br />
<br />
	if( SUCCEEDED( hr ) )<br />
	{<br />
		ZeroMemory( &dxDiagInitParams, sizeof( DXDIAG_INIT_PARAMS ) );<br />
<br />
		dxDiagInitParams.dwSize = sizeof( DXDIAG_INIT_PARAMS );<br />
		dxDiagInitParams.dwDxDiagHeaderVersion = DXDIAG_DX9_SDK_VERSION;<br />
		dxDiagInitParams.bAllowWHQLChecks = FALSE;<br />
		dxDiagInitParams.pReserved = NULL;<br />
<br />
		hr = pDxDiagProvider->lpVtbl->Initialize( pDxDiagProvider, &dxDiagInitParams );

I hope this helps.

Human beings were not meant to sit in little cubicles staring at computer screens all day, filling out useless forms and listening to eight different bosses drone on about about mission statements. -- Peter Gibbons

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