How do i make a array of user defined structure and creat a pointer for the same

Question

Function
The prototype of the dll function is
unsigned long PassThruIoctl(unsigned long A, unsigned long B, void *pvar1, void *pvar2);
"void *pvar1" and "void *pvar2" are pointers to different Structures. The value of  "unsigned long B" will determine what kind of Structure the pointer will represent.
One sample structure is given below when pvar1 is the pointer to SCONFIG_LIST.
typedef struct
      unsigned long ParameterID;    // this an input to the dll
      unsigned long Value;          // this is an output from dll
} SCONFIG;
typedef struct
      unsigned long NumOfParams;    // the no. of elements(SCONFIG) in array
(input)
      SCONFIG *ConfigPtr;           // the pointer to array of SCONFIG
(input)
} SCONFIG_LIST;
The function is supposed to get the values of configuration parameters (from an external interfacing device).
When I tried to run the function as shown in the attached VI, I always end up with error. The error I get is saying something about DLL corrupting the memory of Lab View.
Solved!
Go to Solution.

Answer 1

What will be the structure for pVar2?
One issue that I can see in you code is, for pvar1 instead of passing an array of clusters, you are passing a cluster of SCONFIG. Also you need to initialize the numbr of elements in the array before passing it to the DLL (see attached code). In this I have assumed that pVar2 is also expecting a similar input.
I was not able to run the code here becasue the dll is not there. So please try and let me know.
"A VI inside a Class is worth hundreds in the bush"
യവന്‍ പുലിയാണു കേട്ടാ!!!
Attachments:
GETCONFIG_2.vi ‏9 KB