CODEWITHSUNDEEP
c++struct
msbir
msbir

Reputation: 67

C++ struct access violation

I have the following struct defined in the header file:

typedef struct _wfs_cdm_physicalcu
{
    LPSTR           lpPhysicalPositionName;
    CHAR            cUnitID[5];
    ULONG           ulInitialCount;
    ULONG           ulCount;
    ULONG           ulRejectCount;
    ULONG           ulMaximum;
    USHORT          usPStatus;
    BOOL            bHardwareSensor;
} WFSCDMPHCU, * LPWFSCDMPHCU;

And in my code file I try to use it like this:

LPWFSCDMPHCU cdm_physical_cass;
strcpy(cdm_physical_cass->cUnitID, "1234");
cdm_physical_cass->lpPhysicalPositionName = "DISP1";
cdm_physical_cass->bHardwareSensor = FALSE;
cdm_physical_cass->ulInitialCount = 100;

The code compiles fine, however I get access violation on that strcpy so I think the struct is not initialized properly. Any thoughts?

Upvotes: 0

Views: 983

Answers (3)

Manos Nikolaidis
Manos Nikolaidis

Reputation: 22224

LPWFSCDMPHCU cdm_physical_cass; is not a struct it's a pointer to a struct of type WFSCDMPHCU. You must allocate memory for the struct pointed to by cdm_physical_cass. The function WFMAllocateBuffer is recommended for that.

Upvotes: 1

Taoufik J
Taoufik J

Reputation: 800

Since LPWFSCDMPHCU is a pointer and not a struct , you'll need to allocate memory(malloc or new depending of the language) for that pointer ( LPWFSCDMPHCU ) then you can use the fields.

Upvotes: 0

Jarod42
Jarod42

Reputation: 217255

cdm_physical_cass is not initialized/allocated. You have to call

LPWFSCDMPHCU cdm_physical_cass = new WFSCDMPHCU;

Better would be to use smart pointers (as std::unique_ptr).

Upvotes: 4

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