Checking if two lists of objects are equal - asp.net

Question

I need to compare the values of two lists of objects in VB.NET in a web application. I can't seem to find any working examples of how to do this.
I have tried the example here: https://learn.microsoft.com/en-us/dotnet/api/system.linq.enumerable.sequenceequal?view=netframework-4.0
Where they implement a custom interface for doing so. But even using the exact code gives me errors.
Here is the code I'm currently trying. It's basically the same thing as Microsoft's example but using my own class:
Public Class ForumWithName
Inherits IEquatable(Of ForumWithName)
Private mForumID As Integer
Public Property ForumID() As Integer
Get
Return mForumID
End Get
Set(value As Integer)
mForumID = value
End Set
End Property
Private mForumName As String
Public Property ForumName As String
Get
Return mForumName
End Get
Set(value As String)
mForumName = value
End Set
End Property
Private mSubscribed As Boolean
Public Property Subscribed As Boolean
Get
Return mSubscribed
End Get
Set(value As Boolean)
mSubscribed = value
End Set
End Property
Public Function Compare(ByVal other As ForumWithName) As Boolean
If other Is Nothing Then Return False
Return Me.ForumID = other.ForumID AndAlso Me.Subscribed = other.Subscribed
End Function
Public Overrides Function Equals(ByVal obj As Object) As Boolean
Return Compare(TryCast(obj, ForumWithName))
End Function
Public Overrides Function GetHashCode() As Integer
Return (ForumID, Subscribed).GetHashCode()
End Function
End Class
This code fails to compile because of a few errors:
"Classes can inherit only from other classes"
"Predefined type 'ValueTuple(Of,) is not defined or imported."
"Visual Basic 10.0 does not support tuples"
"'GetHashCode' is not a member of '(ForumID as Integer, Subscribed as Boolean)'"
Once I get this code to work, my plan is to compare two lists of the "ForumWithName" class above.
For example(assume SubscribedsForum1 and SubscribedForums2 are both Lists(Of ForumWithName)):
If SubscribedForums1.SequenceEqual(SubscribedForums2) Then
Return True
Else
Return False
End If

Answer 1

IEquatable is an Interface, it needs to be Implemented and not inherited. (I am guessing here, but I think it's a Typo in the MSDN page you linked)
Change the class declare from:
Public Class ForumWithName
Inherits IEquatable(Of ForumWithName)
to be
Public Class ForumWithName
Implements IEquatable(Of ForumWithName)
Once you have done that, you will also need to add this function
Public Overloads Function Equals(other As ForumWithName) As Boolean Implements IEquatable(Of ForumWithName).Equals
Return Compare(TryCast(other, ForumWithName))
End Function
To work around the problem of not being able to use Tuples, you should be able to use this:
Public Overrides Function GetHashCode() As Integer
Return (ForumID & Subscribed).GetHashCode()
End Function
EDIT:
On a side note, you may want to include the properties ForumName and Subscribed in the GetHashCode function to check if the objects are truly equal to one another.