https://barnamenevis.org/showpo...&postcount=120

کلاس مورد نظر باید اینترفیس IComparable رو پیاده سازی کند. (این اینترفیس تنها یک متود CompareTo دارد)
به نحوه ی پیاده سازی متود CompareTo دقت کنید :
کد:

Public Class Person

    Implements IComparable



    Private _firstname As String

    Public Property Firstname() As String

        Get

            Return _firstname

        End Get

        Set(ByVal value As String)

            _firstname = value

        End Set



    End Property



    Private _lastname As String

    Public Property Lastname() As String

        Get

            Return _lastname

        End Get

        Set(ByVal value As String)

            _lastname = value

        End Set



    End Property



    Private _age As Integer

    Public Property Age() As Integer

        Get

            Return _age

        End Get

        Set(ByVal value As Integer)

            _age = value

        End Set



    End Property



    Public Sub New(ByVal firstname As String, ByVal lastname As String, ByVal age As Integer)



        _firstname = firstname

        _lastname = lastname

        _age = age

    End Sub



    Public Function CompareTo(ByVal obj As Object) As Integer Implements IComparable.CompareTo



        If obj.GetType Is GetType(Person) Then



            Dim p2 As Person = obj

            Return _firstname.CompareTo(p2.Firstname)

        Else

            Throw New ArgumentException("Object is not a Person.")

        End If

    End Function





    Public Overrides Function ToString() As String



        Return String.Format("{0} {1}, Age = {2}", _firstname, _lastname, _age.ToString())

    End Function

End Class


مثال - Sort کردن افراد از روی اسم کوچک (استفاده از کلاس بالا) :
کد:




Dim persons As List(Of Person) = New List(Of Person)()

        persons.Add(New Person("Behrouz", "Rad", 30))

        persons.Add(New Person("Omid", "Mottaghi Rad", 31))

        persons.Add(New Person("Mehdi", "Keramati", 32))

        persons.Add(New Person("Ali", "Keshavarz", 33))

        persons.Add(New Person("Mohammad", "Heshemian", 34))

        persons.Add(New Person("Farhad", "XXX", 35))



        '//Before Sorting

        ListBox1.Items.AddRange(persons.ToArray())



        '//ُSorting List

        persons.Sort()



        '//Sorted List

        listBox2.Items.AddRange(persons.ToArray
())