Is there a quick and efficient way to make classes equitable?

Question

I have many classes with often many properties/fields of primitive types or array/nullable of primitive types.

Public Class ClassN
    Public P1 As Integer
    Public P2 As Byte()
    Public P3 As String
    Public P4 As Short?
    '...
    Public P17 As Boolean
    Public P18 As Char()
End Class

At this point I've come up with a solution using attributes and a "equality service class" which performs the equality test. But is there a quicker and a more efficient way to implement this?

Code behind

<AttributeUsage((AttributeTargets.Field Or AttributeTargets.Property), AllowMultiple:=False, Inherited:=False)> _
Public Class EquatableAttribute
    Inherits Attribute
End Class

Public Class ClassN
    Implements IEquatable(Of ClassN)

    <Equatable()> Public P1 As Integer
    <Equatable()> Public P2 As Byte()
    <Equatable()> Public P3 As String
    <Equatable()> Public P4 As Short?
    '...
    <Equatable()> Public P17 As Boolean
    <Equatable()> Public P18 As Char()

    Public Overrides Function Equals(obj As Object) As Boolean
        Return Me.Equals(TryCast(obj, ClassN))
    End Function

    Public Overloads Function Equals(obj As ClassN) As Boolean Implements System.IEquatable(Of ClassN).Equals
        Return EqualityServices.Equals(Of ClassN)(Me, obj)
    End Function

End Class

Public NotInheritable Class EqualityServices

    Private Sub New()
    End Sub

    Public Overloads Shared Function Equals(Of T)(obj1 As T, obj2 As T) As Boolean
        If (obj1 Is Nothing) Then
            Return obj2 Is Nothing
        End If
        If (obj2 Is Nothing) Then
            Return False
        End If
        Dim type As Type = GetType(T)
        Dim members As MemberInfo() = Nothing
        If (Not EqualityServices.EquatableAttributeCache.TryGetValue(type, members)) Then
            members = New MemberInfo(-1) {}
            For Each info As MemberInfo In type.GetMembers((BindingFlags.Public Or BindingFlags.Instance))
                If (info.GetCustomAttributes(EqualityServices.EquatableAttributeType, False).Length > 0) Then
                    Select Case info.MemberType
                        Case MemberTypes.Field
                            Exit Select
                        Case MemberTypes.Property
                            With DirectCast(info, PropertyInfo)
                                If ((Not .CanRead) OrElse (.GetIndexParameters().Length > 0)) Then
                                    Continue For
                                End If
                            End With
                            Exit Select
                        Case Else
                            Continue For
                    End Select
                    ReDim Preserve members(members.Length)
                    members(members.Length - 1) = info
                End If
            Next
            EqualityServices.EquatableAttributeCache.Add(type, members)
        End If
        If (members.Length > 0) Then
            Dim value1 As Object = Nothing
            Dim value2 As Object = Nothing
            For Each info As MemberInfo In members
                Select Case info.MemberType
                    Case MemberTypes.Field
                        With DirectCast(info, FieldInfo)
                            type = .FieldType
                            value1 = .GetValue(obj1)
                            value2 = .GetValue(obj2)
                        End With
                        Exit Select
                    Case MemberTypes.Property
                        With DirectCast(info, PropertyInfo)
                            type = .PropertyType
                            value1 = .GetValue(obj1, Nothing)
                            value2 = .GetValue(obj2, Nothing)
                        End With
                        Exit Select
                    Case Else
                        Continue For
                End Select
                If (type.BaseType Is EqualityServices.ArrayType) Then
                    If (Not EqualityServices.SequenceEqual(CType(value1, Array), CType(value2, Array))) Then
                        Return False
                    End If
                Else
                    If (Not Object.Equals(value1, value2)) Then
                        Return False
                    End If
                End If
            Next
            Return True
        End If
        Return False
    End Function

    Private Shared Function SequenceEqual(ByVal array1 As Array, array2 As Array) As Boolean
        If (array1 Is Nothing) Then
            Return array2 Is Nothing
        End If
        If (array2 Is Nothing) Then
            Return False
        End If
        If (array1.Rank <> array2.Rank) Then
            Return False
        End If
        If (array1.Length <> array2.Length) Then
            Return False
        End If
        Dim length As Integer = (array1.Length - 1)
        If (length > -1) Then
            Dim list1 As IList = CType(array1, IList)
            Dim list2 As IList = CType(array2, IList)
            For index = 0 To length
                If (Not Object.Equals(list1.Item(index), list2.Item(index))) Then
                    Return False
                End If
            Next
        End If
        Return True
    End Function

    Private Shared ReadOnly EquatableAttributeCache As New Dictionary(Of Type, MemberInfo())
    Private Shared ReadOnly EquatableAttributeType As Type = GetType(EquatableAttribute)
    Private Shared ReadOnly ArrayType As Type = GetType(Array)

End Class

Answer 1

ReSharper can generate the relevant Equals, GetHashCode, etc. or an IEqualityComparer code for you.

You just, well, need ReSharper.

Here's an example (it's C# because I only have the C#-Edition of ReSharper at hand):