char pointer in a stucture for dll

[Yannick]

Hi,

I have to send a structure to a dll, with a pointer to a char in. Here is the structure :

--------------------------

Struct Reference

Data Fields

unsigned long CamType

16 Bit used, hardware id of camera

unsigned long VendorID

24 Bit used, baumer ieee id

unsigned long ChipIDHi

8 Bit used, serial number of 1394 interface

unsigned long ChipIDLo

32 Bit used, serial number of 1394 interface

unsigned long Payloadsize

payloadsize of camera device

unsigned long Reserved [8]

char DspVersion [32]

SignProc null terminated ansii string.

char HwcVersion [32]

label

unsigned long CamLabel

32 Bit used, label as logical camera id

char * CamName

null terminated ansii string

------------------------------

Can I do this without using CIN method ? If I can't, could you help me, I tried but I failed !

here is the dll function

FX_DeviceInfo( devNum, &DevInformation ); where &DevInformation is the structure !

Thanks

[Yannick]

i used this method http://forums.lavag.org/index.php?act=Atta...ost&id=1974 to put a cluster in input of the dll, but the output is a different cluster.

At input there's 2 arrays of 32 chars, and at output, the arrays are only composed of 8 chars.

edit :

I succeeds with the .doc method. When I transformed the array in cluster, i didn't change the default size of cluster.

Thanks !

[Rolf Kalbermatter]

QUOTE(Yannick @ Oct 4 2007, 03:18 AM)

Hi,

I have to send a structure to a dll, with a pointer to a char in. Here is the structure :

Duplicate post, see http://forums.ni.com/ni/board/message?board.id=170&message.id=276066#M276066' target="_blank">here.

The explanation in that post for string pointers inside a structure is wrong. It won't work like that without extra measures. Depending on the DLL it may crash immediately, corrupt some memory silently and crash later on, but something will go wrong sooner or later.

Rolf Kalbermatter

[hviewlabs]

Maybe, pointer functions newly available in 8.5 (and DLL Wizard that uses them in wrappers) can help:

http://forums.lavag.org/index.php?showtopi...ost&p=38888

[hviewlabs]

Maybe, pointer functions newly available in 8.5 (and DLL Wizard that uses them in wrappers) can help:

http://forums.lavag.org/index.php?showtopi...ost&p=38888

[Rolf Kalbermatter]

QUOTE(hviewlabs @ Nov 20 2007, 09:03 PM)

Maybe, pointer functions newly available in 8.5 (and DLL Wizard that uses them in wrappers) can help:

http://forums.lavag.org/index.php?showtopi...ost&p=38888

Try to use the library import wizard in 8.5. It can do some of these things for not to complicated structures, but if that does not work those functions won't help you magically. You will have to understand at least as much about C and pointers in C as you would need to write your own wrapper DLL in C to deal with that in a more clean and much easier to maintain manner.

Rolf Kalbermatter

[Rolf Kalbermatter]

QUOTE(hviewlabs @ Nov 20 2007, 09:03 PM)

Maybe, pointer functions newly available in 8.5 (and DLL Wizard that uses them in wrappers) can help:

http://forums.lavag.org/index.php?showtopi...ost&p=38888

Try to use the library import wizard in 8.5. It can do some of these things for not to complicated structures, but if that does not work those functions won't help you magically. You will have to understand at least as much about C and pointers in C as you would need to write your own wrapper DLL in C to deal with that in a more clean and much easier to maintain manner.

Rolf Kalbermatter