Undefined Value

[krishnasamy]

Hi,

I have declaring the variable following way in vc++,

BYTE* pTemplate = NULL;

BYTE* pTemp;

When I Trace the "pTemplate" value at runtime which returns "<Undefined Value>".

The same in C# defined,

IntPtr pTemplate
byte[] template = null;
IntPtr pTemp;

what is the problem of defining in vc++?

[dmjpro]

Hi,

I have declaring the variable following way in vc++,

BYTE* pTemplate = NULL;

BYTE* pTemp;

When I Trace the "pTemplate" value at runtime which returns "<Undefined Value>".

The same in C# defined,

IntPtr pTemplate
byte[] template = null;
IntPtr pTemp;

what is the problem of defining in vc++?

What is BYTE?
Is that any user defined Data Type?
And please could you give me the whole code so that I can trace it?

Kind regards,
Dmjpro.

[krishnasamy]

What is BYTE?
Is that any user defined Data Type?
And please could you give me the whole code so that I can trace it?

Kind regards,
Dmjpro.

Hi,
Thanks for your reply.

When i give the definition of that BYTE type i get the following reference in system header file.

typedef unsigned char BYTE;

Its not user defined data type. Its based vc6.0 data type.

Here i given my code.
[code=c]
BYTE* pTemplate = NULL;
BYTE* pTemp;
int err = PR2_Ptr(IPhandl e, 1, Data, pTemp, size, quality, FALSE, 500, 500);
txt_ChkRet->Text = err.ToString();
[/code]

[Banfa]

What does the function PR2_Ptr do?
What does the function PR2_Ptr expect to be passed as arguments?

I suspect the problem is that you pass PR2_Ptr the pTemp parameter which is a NULL pointer, I think you probably need to allocate memory to it first.

[krishnasamy]

What does the function PR2_Ptr do?
What does the function PR2_Ptr expect to be passed as arguments?

I suspect the problem is that you pass PR2_Ptr the pTemp parameter which is a NULL pointer, I think you probably need to allocate memory to it first.

Thanks for your reply.

PR2_Ptr is a Function Prototype. I declare that below way,

typedef int (CALLBACK* PROC2_IP) ( IDS_HANDLE hHandle, int numFingers, CaptureData pData[], BYTE* &pTemplate, unsigned int &size, unsigned char &quality, bool bQuick, int MaxWidth, int MaxHeight);

HINSTANCE hinstLib_IP;

INIT_IP IP_InitPtr;
PROC2_IP PR2_Ptr;

PR2_Ptr = (PROC2_IP) GetProcAddress( hinstLib_IP, "process2") ;

if (fRunTimeLinkSu ccess = (PR2_Ptr != NULL))
(PR2_Ptr);


int err = PR2_Ptr(IPhandl e, 1, Data, pTemplate, size, quality, FALSE, 500, 500);

txt_ChkRet->Text = err.ToString();


I have used above code. How to allocate the memory to pTemplate?

Please suggest me.