clistiterator.cls

Visual Basic 6 大学教程的代码

VERSION 1.0 CLASS
BEGIN
  MultiUse = -1  'True
  Persistable = 0  'NotPersistable
  DataBindingBehavior = 0  'vbNone
  DataSourceBehavior  = 0  'vbNone
  MTSTransactionMode  = 0  'NotAnMTSObject
END
Attribute VB_Name = "CListIterator"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = True
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
' Fig. 21.3
' Class CListIterator
Option Explicit
Private mBookmark As CListNode
Private mFirstNode As CListNode

Public Property Let StartNode(ByVal vNewValue As Variant)
   Set mFirstNode = vNewValue
   Set mBookmark = mFirstNode
End Property

' return next item in list
Public Function NextItem()
   Dim tempData As Variant
   
   If mBookmark Is Nothing Then
      NextItem = Null
   Else
      tempData = mBookmark.Data
      Set mBookmark = mBookmark.NextNode
      NextItem = tempData
   End If
End Function

Public Function HasMoreItems() As Boolean
   HasMoreItems = IIf(Not mBookmark Is Nothing, True, False)
End Function

' reset mBookmark to beginning of list
Public Sub ResetmBookmark()
   mBookmark = mFirstNode
End Sub