Hi again,

   I created a thread some days ago, while I was trying to access a C++ DLL
using my C# program. First of all, I want to thanks all the guys who helped
me. But I still have a problem... My C++ DLL has a function which has the
following prototype:

   long FF_Function(void* inInstance, char* inDate, FF_Struct**
outStructure, long* outNumber);

   The structure has the following prototype:

   struct FF_Struct
       {
       long    m_Index;
       char    m_ID[FF_ID_LEN];
       char    m_Date[FF_DATETIME_LEN];
       };

   I know that the function should return me an array of FF_Struct, and
that the parameter outNumber has the number of elements stored in the
FF_Struct array. Now, I'm tring to translate it in C#, and here is what I
did (which does not work, of course):

   public class FF_AO_OrderList
       {
       public int index;
       [MarshalAs(UnmanagedType.ByValTStr, SizeConst = FF_ID_LEN)]
       public string numeroCommande;
       [MarshalAs(UnmanagedType.ByValTStr, SizeConst = FF_DATETIME_LEN)]
       public string dateCommande;
       }

   [DllImport("FF_myDLL.dll")]
   public static extern int FF_Function
       (
       IntPtr inInstance,
       [MarshalAs(UnmanagedType.LPTStr)]
       string date,
       out FF_Struct[] outStructure,
       out int outNumber
       );

   I can access the function, but it returns me an error message ("The
parameters specified for the interface are incorrect."). I don't know how to
deal with this structure and its double pointer. Even in unsafe mode (then I
use a FF_Struct** parameter), I have the same problem.

   Does anyone knows what I'm missing ? I'd greatly appreciate some help,
as I'm completely out of ideas... Thanks !!!!

   Laurent