Imports System
Imports System.Collections
Public Class ROCollection
Inherits ReadOnlyCollectionBase
Public Sub New(sourceList As IList)
InnerList.AddRange(sourceList)
End Sub 'New
Default Public ReadOnly Property Item(index As Integer) As [Object]
Get
Return InnerList(index)
End Get
End Property
Public Function IndexOf(value As [Object]) As Integer
Return InnerList.IndexOf(value)
End Function
Public Function Contains(value As [Object]) As Boolean
Return InnerList.Contains(value)
End Function
End Class
Public Class SamplesCollectionBase
Public Shared Sub Main()
Dim myAL As New ArrayList()
myAL.Add("A")
myAL.Add("B")
myAL.Add("C")
Dim myCol As New ROCollection(myAL)
PrintIndexAndValues(myCol)
End Sub
Public Shared Sub PrintIndexAndValues(myCol As ROCollection)
Dim i As Integer
For i = 0 To myCol.Count - 1
Console.WriteLine(" [{0}]: {1}", i, myCol(i))
Next i
Console.WriteLine()
End Sub
End Class