Criando coleções personalizadas com par Nome/Objeto
Quando desejamos criar coleções personalizadas normalmente criamos uma classe personalizada herdando de CollectionBase . Porém a collectionBase cria coleções apenas indexadas, não permite que utilizemos um par Key/Valor
Para utilizarmos isso deveremos fazer a herança de outra classe base: NameObjectCollectionBase.
Exemplo:
Public Class NameObjectCollection
Inherits System.Collections.Specialized.NameObjectCollectionBase
Sub Add(ByVal key As String, ByVal obj As Object)
Me.BaseAdd(key, obj)
End Sub
Sub Clear()
Me.BaseClear()
End Sub
The Remove method overload that takes a string key
Sub Remove(ByVal key As String)
Me.Remove(key)
End Sub
The Remove method overload that takes a numeric index
Sub Remove(ByVal index As Integer)
Me.Remove(index)
End Sub
The Item property overload that takes a string key
Default Property Item(ByVal key As String) As Object
Get
Return Me.BaseGet(key)
End Get
Set(ByVal Value As Object)
Me.BaseSet(key, Value)
End Set
End Property
The Item property overload that takes a numeric index
Default Property Item(ByVal index As Integer) As Object
Get
Return Me.BaseGet(index)
End Get
Set(ByVal Value As Object)
Me.BaseSet(index, Value)
End Set
End Property
End Class
Dim col As New NameObjectCollection
col.Add("one", 1)
col.Add("two", 2)
col.Add("three", 3)
visit elements by their index
For i As Integer = 0 To col.Count - 1
Console.WriteLine("col({0}) = {1}", i, col(i))
Next
visit elements by their key
For Each key As String In col
Console.WriteLine("col({0}) = {1}", key, col(key))
Next
