howto parse struct to C++ dll from C#
- by Nerds Rule
I am trying to call a function in a unmanaged C++ dll.
It has this prototype:
[DllImport("C:\\Program Files\\MySDK\\VSeries.dll", EntryPoint = "BII_Send_Index_Template_MT" )]
internal unsafe static extern Int32 BII_Send_Index_Template_MT(IntPtr pUnitHandle, ref BII_Template template, Int32 option, Boolean async);
BII_Template template = new BII_Template();
error_code = BII_Send_Index_Template_MT(pUnitHandle, ref template, option, false);
I is how I define the BII_Template struct in C#:
public unsafe struct BII_Template {
public ulong id;
public ulong employee_id;
public ulong password;
public byte sensor_version;
public byte template_version;
public fixed char name[16];
public byte finger;
public byte admin_level;
public byte schedule;
public byte security_thresh;
public fixed byte noise_level[18];
public byte corramb;
public byte reference_x;
public byte reference_y;
public fixed byte ihcore[3];
public fixed byte ivcore[3];
public byte temp_xoffset;
public byte temp_yoffset;
public byte index;
public fixed byte inphase[5500];
};
It build and when I run it the dll return error_code = "The record checksum is invalid."
I assume that I am using the ref keyword in a wrong way or the size of some of the elements in the struct is wrong.
----- EDIT ------------
Here is the struct in C++:
typedef struct {
unsigned long id;
unsigned long employee_id;
unsigned long password;
unsigned char sensor_version;
unsigned char template_version;
char name[16];
unsigned char finger;
unsigned char admin_level;
unsigned char schedule;
unsigned char security_thresh;
unsigned char noise_level[18];
unsigned char corramb ;
unsigned char reference_x ;
unsigned char reference_y ;
unsigned char ihcore[NUM_CORE];
unsigned char ivcore[NUM_CORE];
unsigned char temp_xoffset;
unsigned char temp_yoffset;
unsigned char index;
unsigned char inphase[PACKED_ARRAY_SIZE];
} BII_Template;
