IEnumerable, IEnumerator (VB) : IEnumerable « Collections « ASP.NET Tutorial

<%@ Page Language="VB" %>
<script runat="server">
Sub Page_Load()
  Dim _customCollection = New CustomCollection(10)  
  
  DemoOutput.Text = ""
  Dim _customItem As CustomItem
  For Each _customItem In _customCollection
    DemoOutput.Text += _customItem.Index & "<br />"
  Next
End Sub

Public Class CustomCollection
  Implements IEnumerable, IEnumerator

  Private customItems() As CustomItem
  Private currentIndex As Integer = -1

  Public Sub New(ByVal Count As Integer)
    Dim index As Integer

    ReDim customItems(Count - 1)
    For index = 0 To Count - 1
      customItems(index) = New CustomItem(index)
    Next
  End Sub

#Region "Implementation of IEnumerable"
  Public Function GetEnumerator() As IEnumerator Implements IEnumerable.GetEnumerator
    Return CType(Me, IEnumerator)
  End Function
#End Region

#Region "Implementation of IEnumerator"
  Public Sub Reset() Implements IEnumerator.Reset
    currentIndex = -1
  End Sub

  Public Function MoveNext() As Boolean Implements IEnumerator.MoveNext
    If currentIndex < customItems.Length - 1 Then
      currentIndex = currentIndex + 1
      Return True
    Else
      Return False
    End If
  End Function

  Public ReadOnly Property Current() As Object Implements IEnumerator.Current
    Get
      Return customItems(currentIndex)
    End Get
  End Property
#End Region
End Class

Public Class CustomItem
  Private _index As Integer

  Public ReadOnly Property Index() As Integer
    Get
      Return _index
    End Get
  End Property

  Public Sub New(ByVal Index As Integer)
    _index = Index
  End Sub
End Class
</script>
<html>
  <head>
    <title>Creating a Custom Collection</title>
  </head>
  <body>
    <form id="MainForm" runat="server">
      Output of Looping through a Custom Collection
      <br />
      <asp:literal id="DemoOutput" runat="server" />
    </form>
  </body>
</html>
7.6.IEnumerable
	7.6.1.	Using CustomCollection
	7.6.2.	IEnumerable, IEnumerator
	7.6.3.	IEnumerable, IEnumerator (VB)