private unsafe static int TryExcelImpl4(int xlFunction, out object result, params object[] parameters)
{
int xlReturn;
// Set up the memory to hold the result from the call
XlOper resultOper = new XlOper();
resultOper.xlType = XlType.XlTypeEmpty;
XlOper *pResultOper = &resultOper; // No need to pin for local struct
// Special kind of ObjectArrayMarshaler for the parameters (rank 1)
using (XlObjectArrayMarshaler paramMarshaler = new XlObjectArrayMarshaler(1, true))
{
XlOper **ppOperParameters = (XlOper **)paramMarshaler.MarshalManagedToNative(parameters);
xlReturn = Excel4v(xlFunction, pResultOper, parameters.Length, ppOperParameters);
}
// pResultOper now holds the result of the evaluated function
// Get ObjectMarshaler for the return value
ICustomMarshaler m = XlObjectMarshaler.GetInstance("");
result = m.MarshalNativeToManaged((IntPtr)pResultOper);
// And free any memory allocated by Excel
Excel4v(xlFree, (XlOper *)IntPtr.Zero, 1, &pResultOper);
return(xlReturn);
}
internal static void XlAutoFree(IntPtr pXloper)
{
// CONSIDER: This might be improved....
// Another option would be to have the Com memory allocator run in unmanaged code.
// Right now I think this is OK, and easiest from where I'm coming.
// This function can only be called after a return from a user function.
// I just free all the possibly big memory allocations.
XlObjectArrayMarshaler.FreeMemory();
}
