Question

Is this possible?

Public Class Foo
    public var as string

    public sub Load(byval filename as string)
        'This is done
        [...]
        oItem = [...] 'Code to deserialize

        me = oItem 'THIS LINE
    end sub
end class

So that you can load foo from the serialized file like so:

Public Sub Main
    Dim f as Foo = new Foo()
    f.load("myFile")
end sub

Up until now i’ve had a function that that returns Foo as Object (I’m trying to make the serialize / deserialize process general so I can just copy and paste and avoid explicitly setting each variable)

Answer 1

No, what you want to do in your case is have Load be a Shared Function that returns the newly created item.

More like:

Public Class Foo
    public var as string

    public Shared Function Load(byval filename as string) As Foo
        'This is done
        [...]
        oItem = [...] 'Code to deserialize

        Return oItem
    end sub
end class

Public Sub Main
    Dim f as Foo
    f = Foo.load("myFile")
end sub

Also, rather than embedding the deserialization directly into each class, you can have a general purpose method, such as:

''' <summary>
''' This method is used to deserialize an object from a file that was serialized using the SoapFormatter
''' </summary>
''' <param name="sFileName"></param>
''' <returns></returns>
''' <remarks></remarks>
Public Function Deserialize(Of T)(ByVal sFileName As String) As T
    ' Exceptions are handled by the caller

    Using oStream As Stream = File.Open(sFileName, FileMode.Open, IO.FileAccess.Read)
        If oStream IsNot Nothing Then
            Return DirectCast((New SoapFormatter).Deserialize(oStream), T)
        End If
    End Using

    Return Nothing
End Function

which you can then call as:

Public Sub Main
    Dim f as Foo
    f = Deserialize(Of Foo)("myFile")
end sub