Wrapper for DOTNET to native written in C++ CLI BestWay to pass structures?

Question

Yet I am writing a wrapper in C++ CLI for our application to give some new parts (written in C#) save and easy access to old native libraries. Therefore I need to pass some structures from C# to C++. These structures are defined in C++ Cli (dotnet) and also in C++.

Example:

\\C+++
typedef struct
{                                                           
INFO16   jahr   ;
INFO8    monat  ;
INFO8    tag    ;
INFO8    stunde ;
INFO8    minute ;
}
SDATUM;

\\c++ cli
[StructLayout(LayoutKind::Explicit)]
public value struct SDATUM
{
public:
  [FieldOffset(0)]
  UInt16 jahr;
  [FieldOffset(2)]
  Byte monat;
  [FieldOffset(3)]
  Byte tag;
  [FieldOffset(4)]
  Byte stunde;
  [FieldOffset(5)]
  Byte minute;
};

Now I provide some functions in C++ cli which accept this type as dotnet type SDATUM in form of pass by value,by reference (sdatum%) and pointer sdatum* like there corresponding native functions. What do I need to convert/cast these struct?

Answer 1

I found another solution which is very easy, short and does not need copying data. You could call native functions which want a C SDATUM in this way:

//signature
void someFunction(SDATUM datum);

void someFunctionWrapper(SDATUM datum){
pin_ptr<SDATUM>  datum_pin=&datum;


//::SDATUM refers to the C-Type
someFunction(*(::SDATUM*)datum_pin);
}

I tested it and it works because both SDATUM Structs have the same bit structure. Because I only call short native functions I think fragmentation is no problem.