IEnumerable<T> Interface

$0Notes to Implementers.  IEnumerable<T> is included for parity with non-generic collections; implementing IEnumerable<T> allows a generic collection to be passed to a method that expects an IEnumerable object.$0 $0

$0Notes to Implementers.  IEnumerable is included for parity with non-generic collections; implementing IEnumerable allows a generic collection to be passed to a method that expects an IEnumerable object.$0

linked from http://msdn.microsoft.com/en-us/library/bb360635.aspx, i went into this page, i cont file count method some times.

dont know why.

''' <summary>
''' Copyright © Omar Amin Ibrahim 2011
''' silverlight1212@yahoo.com
''' </summary>
''' <remarks></remarks>
Public NotInheritable Class RiverNileEnumerator

    Public Shared Function GetList(Of T)(ByVal list As IList(Of T)) As RiverNileListEnumerator(Of T)
        If (list Is Nothing) Then
            Throw New ArgumentNullException("list")
        End If
        Return New RiverNileListEnumerator(Of T)(list)
    End Function

    Public Shared Function GetCollection(Of T)(ByVal collection As ICollection(Of T)) As RiverNileCollectionEnumerator(Of T)
        If (collection Is Nothing) Then
            Throw New ArgumentNullException("collection")
        End If
        Return New RiverNileCollectionEnumerator(Of T)(collection)
    End Function

    Public Class RiverNileCollectionEnumerator(Of T)
        Implements IEnumerable(Of T)
        Implements IEnumerator(Of T)

#Region " Fields "

        Private _collectiont As ICollection(Of T)
        Private _index As Integer
        Private _current As T

#End Region

#Region " Constructor "

        Public Sub New(ByVal collection As ICollection(Of T))
            MyBase.New()
            _collectiont = collection
            _index = -1
            _current = CType(Nothing, T)
        End Sub

#End Region

#Region " Properties "

        Public ReadOnly Property Current As T
            Get
                If _current Is Nothing Then
                    Throw New InvalidOperationException()
                End If

                Return _current
            End Get
        End Property

        Private ReadOnly Property System_Collections_Generic_Current As T Implements System.Collections.Generic.IEnumerator(Of T).Current
            Get
                Return Me.Current
            End Get
        End Property

        Private ReadOnly Property System_Collections_Current As Object Implements System.Collections.IEnumerator.Current
            Get
                Return Me.Current
            End Get
        End Property

#End Region

#Region " Methods "

        Public Function GetEnumerator() As IEnumerator(Of T)
            Return New RiverNileCollectionEnumerator(Of T)(Me._collectiont)
        End Function

        Public Function MoveNext() As Boolean
            _index = _index + 1
            If _index = _collectiont.Count Then
                Return False
            Else
                _current = _collectiont(_index)
            End If
            Return True
        End Function

        Public Sub Reset()
            _index = -1
            _current = CType(Nothing, T)
        End Sub

        Private Function System_Collections_Generic_GetEnumerator() As System.Collections.Generic.IEnumerator(Of T) Implements System.Collections.Generic.IEnumerable(Of T).GetEnumerator
            Return Me.GetEnumerator
        End Function

        Private Function System_Collections_GetEnumerator() As System.Collections.IEnumerator Implements System.Collections.IEnumerable.GetEnumerator
            Return Me.GetEnumerator
        End Function

        Private Function System_Collections_MoveNext() As Boolean Implements System.Collections.IEnumerator.MoveNext
            Return MoveNext()
        End Function

        Private Sub System_Collections_Reset() Implements System.Collections.IEnumerator.Reset
            Me.Reset()
        End Sub

        Private Sub System_IDisposable_Dispose() Implements IDisposable.Dispose
            ' do nothing
        End Sub

#End Region

    End Class

    Public Class RiverNileListEnumerator(Of T)

        Implements IEnumerable(Of T)
        Implements IEnumerator(Of T)

#Region " Fields "

        Private _list As IList(Of T)
        Private _index As Integer
        Private _current As T

#End Region

#Region " Constructor "

        Public Sub New(ByVal list As IList(Of T))
            MyBase.New()
            _list = list
            _index = -1
            _current = CType(Nothing, T)
        End Sub

#End Region

#Region " Properties "

        Public ReadOnly Property Current As T Implements System.Collections.Generic.IEnumerator(Of T).Current
            Get
                If _current Is Nothing Then
                    Throw New InvalidOperationException()
                End If

                Return _current
            End Get
        End Property

        Private ReadOnly Property System_Collections_Current As Object Implements System.Collections.IEnumerator.Current
            Get
                Return Me.Current
            End Get
        End Property

#End Region

#Region " Methods "

        Public Function GetEnumerator() As System.Collections.Generic.IEnumerator(Of T) Implements System.Collections.Generic.IEnumerable(Of T).GetEnumerator
            Return New RiverNileListEnumerator(Of T)(Me._list)
        End Function

        Private Function System_Collections_GetEnumerator() As System.Collections.IEnumerator Implements System.Collections.IEnumerable.GetEnumerator
            Return Me.GetEnumerator
        End Function

        Public Function MoveNext() As Boolean Implements System.Collections.IEnumerator.MoveNext
            _index = _index + 1
            If _index = _list.Count Then
                Return False
            Else
                _current = _list(_index)
            End If
            Return True
        End Function

        Public Sub Reset() Implements System.Collections.IEnumerator.Reset
            _index = -1
            _current = CType(Nothing, T)
        End Sub

        Private Sub System_IDisposable_Dispose() Implements IDisposable.Dispose
            ' do nothing
        End Sub

#End Region

    End Class

End Class ' RiverNileEnumerator



.....How To Use ......

Public Class Form1

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        Dim ColorList As ICollection(Of KnownColor) = New List(Of KnownColor) From {KnownColor.Aqua, KnownColor.Red, KnownColor.Black}

        For Each clr As KnownColor In RiverNileEnumerator.GetCollection(ColorList)
            ListBox1.Items.Add(clr)
        Next

        Dim StringList As IList(Of String) = New List(Of String) From {"Omar", "Amin", "Ibrahim"}

        For Each Str As String In RiverNileEnumerator.GetList(StringList)
            ListBox2.Items.Add(Str)
        Next
    End Sub


End Class