How to: Convert Between System::Guid and _GUID

The following code sample shows how to convert between a Guid and a _GUID.

Example

// convert_guids.cpp
// compile with: /clr
#include <windows.h>
#include <stdio.h>

using namespace System;

Guid FromGUID( _GUID& guid ) {
   return Guid( guid.Data1, guid.Data2, guid.Data3,
                guid.Data4[ 0 ], guid.Data4[ 1 ],
                guid.Data4[ 2 ], guid.Data4[ 3 ],
                guid.Data4[ 4 ], guid.Data4[ 5 ],
                guid.Data4[ 6 ], guid.Data4[ 7 ] );
}

_GUID ToGUID( Guid& guid ) {
   array<Byte>^ guidData = guid.ToByteArray();
   pin_ptr<Byte> data = &(guidData[ 0 ]);

   return *(_GUID *)data;
}

int main() {
   _GUID ng = {0x11111111,0x2222,0x3333,0x44,0x55,0x55,0x55,0x55,0x55,0x55,0x55};
   Guid mg;

   Console::WriteLine( (mg = FromGUID( ng )).ToString() );
   _GUID ng2 = ToGUID( mg );

   printf_s(  "%x-%x-%x-", ng2.Data1, ng2.Data2, ng2.Data3 );
   for (int i = 0 ; i < 8 ; i++) {
      if (i == 2)
         printf_s("-");
      printf_s("%x", ng2.Data4[i]);
   }
   printf_s("\n");
}

11111111-2222-3333-4455-555555555555
11111111-2222-3333-4455-555555555555

See also

Using C++ Interop (Implicit PInvoke)