IComparable : IComparable « Collections « VB.Net Tutorial

1. VB.Net Tutorial
2. Collections
3. IComparable

Imports System.Collections

Module Test
    Public Sub Main()

        Dim objEmployee1 As New Employee()
        Dim objEmployee2 As New Employee()
        Dim objEmployee3 As New Employee()

        objEmployee1.FirstName = "A"
        objEmployee1.LastName = "B"
        objEmployee2.FirstName = "C"
        objEmployee2.LastName = "D"
        objEmployee3.FirstName = "E"
        objEmployee3.LastName = "F"

        Dim slPeople As New SortedList()

        slPeople.Add(objEmployee1, 1)
        slPeople.Add(objEmployee2, 2)
        slPeople.Add(objEmployee3, 3)

        Dim objDE As DictionaryEntry

        For Each objDE In slPeople
            Console.WriteLine("{0} {1}",CType(objDE.Key, Employee).DisplayName, CType(objDE.Value,Integer))
        Next
    End Sub
End Module

Public Class Employee
    Implements IComparable
    Public FirstName As String
    Public LastName As String

    Public ReadOnly Property DisplayName() As String
        Get
            Return String.Format("{0} {1}", FirstName, LastName)
        End Get
    End Property

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

        Dim objOtherEmployee As Employee
        objOtherEmployee = CType(obj, Employee)

        If objOtherEmployee.LastName > Me.LastName Then
            Return -1
        ElseIf objOtherEmployee.LastName < Me.LastName Then
            Return 1
        Else
            If objOtherEmployee.FirstName > Me.FirstName Then
                Return -1
            ElseIf objOtherEmployee.FirstName < Me.FirstName Then
                Return 1
            Else
                Return 0
            End If
        End If
    End Function
End Class

A B 1
C D 2
E F 3