You can create a clone of any class by calling this helper function:




    Function DeepClone(Of T)(ByRef orig As T) As T

        ' Don't serialize a null object, simply return the default for that object
        If (Object.ReferenceEquals(orig, Nothing)) Then Return Nothing

        Dim formatter As New BinaryFormatter()
        Dim stream As New MemoryStream()

        formatter.Serialize(stream, orig)
        stream.Seek(0, SeekOrigin.Begin)

        Return CType(formatter.Deserialize(stream), T)

    End Function

This works by serializing all the information from your class into a portable object and then rewriting it in order to sever any reference pointers.

> **Note**: The passed in class and any other classes it exposes as properties must be marked [`<Serializable()>`][1] in order to use [`BinaryFormatter.Serialize`][2]



If you want to make your own class expose the clonable method itself, you can add the method and implement the [`ICloneable`][3] interface like this:



    <Serializable()>
    Public Class MyClass : Implements ICloneable

        'NOTE - The Account class must also be Serializable
        Public Property PersonAccount as Account
        Public Property FirstName As String

        Function Clone(ByRef orig As MyClass) As MyClass Implements ICloneable.Clone
    
            ' Don't serialize a null object, simply return the default for that object
            If (Object.ReferenceEquals(orig, Nothing)) Then Return Nothing
    
            Dim formatter As New BinaryFormatter()
            Dim stream As New MemoryStream()
    
            formatter.Serialize(stream, orig)
            stream.Seek(0, SeekOrigin.Begin)
    
            Return CType(formatter.Deserialize(stream), T)
    
        End Function
    
    End Class

> **Note**: Be aware ICloneable comes with it's share of [controversies][4] as it does not indicate to the caller if it is performing a deep or shallow clone.  In reality, you don't need the interface to be able to add the method to your class.

[1]: https://msdn.microsoft.com/en-us/library/System.SerializableAttribute(v=vs.110).aspx
[2]: https://msdn.microsoft.com/en-us/library/System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Serialize(v=vs.110).aspx
[3]: https://msdn.microsoft.com/en-us/library/system.icloneable(v=vs.110).aspx
[4]: https://stackoverflow.com/q/699210/1366033

Can I please have some help to perform a deep copy of an object.

Here is my code:

    Option Explicit On
    Option Strict On

    <Serializable> Public Class [Class]
    Private _Name As String
    Private _ListOfFields As New List(Of Field)

    Public Property Name As String
        Get
            Return _Name
        End Get
        Set(value As String)
            _Name = value
        End Set
    End Property

    Public Property ListOfFields As List(Of Field)
        Get
            Return _ListOfFields
        End Get
        Set(value As List(Of Field))
            _ListOfFields = value
        End Set
    End Property

    Public Function Clone() As [Class]
        Return DirectCast(Me.MemberwiseClone, [Class])
    End Function

    End Class

Field is a Class that I have written myself as well.

What do I need to modify for the Clone() Function to return a deep copy?