private unsafe static int TryExcelImpl12(int xlFunction, out object result, params object[] parameters)
{
int xlReturn;
// Set up the memory to hold the result from the call
XlOper12 resultOper = new XlOper12();
resultOper.xlType = XlType12.XlTypeEmpty;
int i = sizeof(XlOper12);
XlOper12 *pResultOper = &resultOper; // No need to pin for local struct
// Special kind of ObjectArrayMarshaler for the parameters (rank 1)
using (XlObjectArray12Marshaler paramMarshaler = new XlObjectArray12Marshaler(1, true))
{
XlOper12 **ppOperParameters = (XlOper12 **)paramMarshaler.MarshalManagedToNative(parameters);
xlReturn = Excel12v(xlFunction, parameters.Length, ppOperParameters, pResultOper);
}
// pResultOper now holds the result of the evaluated function
// Get ObjectMarshaler for the return value
ICustomMarshaler m = XlObject12Marshaler.GetInstance("");
result = m.MarshalNativeToManaged((IntPtr)pResultOper);
// And free any memory allocated by Excel
Excel12v(xlFree, 1, &pResultOper, (XlOper12 *)IntPtr.Zero);
return(xlReturn);
}
internal static void XlAutoFree12(IntPtr pXloper12)
{
// 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.
XlObjectArray12Marshaler.FreeMemory();
}