The text that you want to transform should be passed to this function.
<DllImport(uCalcDLL, CharSet:=CharSet.Ansi, CallingConvention:=CallingConvention.Cdecl, EntryPoint:="Input")> _
Private Sub Input__(ByVal TransformHandle As IntPtr,ByVal InputStr As String)
End Sub
[DllImport(uCalcDLL, CharSet=CharSet.Ansi, CallingConvention=CallingConvention.Cdecl, EntryPoint="Input")]
protected static extern void Input_(IntPtr TransformHandle, string InputStr);
{DLLImport}procedure Input__(TransformHandle: System.Pointer;InputStr: AnsiString); cdecl; external uCalcDLL name 'Input';
typedef void (* __Input)(void *TransformHandle, CONSTCHAR InputStr );
[DllImport(uCalcLib, CharSet=CharSet::Ansi, CallingConvention=CallingConvention::Cdecl, EntryPoint = "Input")]
static void Input_(void * TransformHandle, MARSHALSTR InputStr);