Register dll!!!!

You need to build your .dll assembly in .NET but have it registered for COM Interop. Have you done this? You also need to define interfaces to your class methods in C# to see the methods properly. Have you done this?

Are you sure?

Please see the example below of some old VB code that works using COM Interop. I think you may not have defined everything properly in your assembly...

Imports System.Security.Cryptography
Imports System.IO
Imports System.Text
Imports System.Text.Encoding
Imports System.Runtime.CompilerServices
Imports System.Runtime.InteropServices

'GUID hard coded to prevent changing on recompile 
<GuidAttribute("9a1ebc2c-f02f-463b-876d-b25431f0696b")> _
'InterfaceType is Dual
<InterfaceType(ComInterfaceType.InterfaceIsDual)> _
'Public Interface created with signatures matching methods in class and properties… 
Public Interface ICrypto
    'Methods 
    Function EncryptString(ByVal Content As String) As Boolean
    Function DecryptString() As Boolean
    Function EncryptFile(ByVal Filename As String, ByVal Target As String) As Boolean
    Function DecryptFile(ByVal Filename As String, ByVal Target As String) As Boolean
    Function GenerateHash(ByVal Content As String) As Boolean
    Function StandardBankGenerateHash(ByVal Content As String, ByVal fileName As String) As Boolean
    Function SetEncryptionAlgorithm(ByVal value As Integer) As Boolean
    Function GetEncryptionAlgorithm() As Integer
    Function SetEncoding(ByVal value As Integer) As Boolean
    Function GetEncoding() As Integer
    Sub Clear()
    'Properties
    Property Key() As String
    Property Content() As String
    ReadOnly Property CryptoException() As CryptographicException

End Interface

'Class defined as ComVisible and GUID static
<ComVisible(True)> _
<GuidAttribute("46155048-ff63-4e63-bc1e-f2e32b66e907")> _
<ProgId("Crypto")> _
<ClassInterface(ClassInterfaceType.None)> _
'Public Interface is Implemented
Public Class Crypto : Implements ICrypto
'Have not expanded the region of Class Variables below…
+ Class Variables Regions

#Region "Public Functions"
Public Property Key() As String Implements ICrypto.Key
        Get
            Return _key
        End Get
        Set(ByVal value As String)
            _key = value
        End Set
End Property
Public Property Content() As String Implements ICrypto.Content
        Get
            Return _content
        End Get
        Set(ByVal Value As String)
            _content = Value
        End Set
End Property
Public ReadOnly Property CryptoException() As CryptographicException        Implements ICrypto.CryptoException
        Get
            Return _exception
        End Get
End Property
Public Function SetEncryptionAlgorithm(ByVal value As Integer) As Boolean Implements ICrypto.SetEncryptionAlgorithm
        _algorithm = value
        Return True
End Function

Public Function GetEncryptionAlgorithm() As Integer Implements ICrypto.GetEncryptionAlgorithm
        Return _algorithm
End Function
Public Function SetEncoding(ByVal value As Integer) As Boolean Implements ICrypto.SetEncoding
        _encodingType = value
        Return True
End Function

Public Function GetEncoding() As Integer Implements ICrypto.GetEncoding
        Return _encodingType
End Function


Public Function EncryptString(ByVal Content As String) As Boolean Implements ICrypto.EncryptString
        Dim cipherBytes() As Byte

        Try
            cipherBytes = _Encrypt(Content)
        Catch ex As CryptographicException
            _exception = New CryptographicException(ex.Message, ex.InnerException)
            Return False
        End Try

        If _encodingType = EncodingType.Hex Then
            _content = BytesToHex(cipherBytes)
        Else
            _content = System.Convert.ToBase64String(cipherBytes)
        End If

        Return True
End Function

Your syntax should be something like...

regasm myNewInterface.dll /tlb:myNewInterace.tlb /codebase

Clearly you would need to have navigated first to the file path where your .dll is otherwise you'll get errors.

Then you should see everything in NAV!
\:D/