hashtable-recupero elementi in ordine di immissione

[pietro09]

c'è il modo di recuperare gli elementi inseriti in un HashTable secondo l'ordine di inserimento? :master:

[djciko]

credo che l'unica sia inserire una chiave con il timestamp relativo all'inserimento, oppure usare un array recuperandoli con l'indice crescente

[pietro09]

Originariamente inviato da djciko
credo che l'unica sia inserire una chiave con il timestamp relativo all'inserimento, oppure usare un array recuperandoli con l'indice crescente

:master: in effetti siamo arrivati alle stesse conclusioni. Però voglio tentare altre strade e chissà :master:

[pietro09]

forse così va :master:

Partial Class prove_a
    Inherits System.Web.UI.Page

    Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim j As New NameObjectCollection()
        j.Add("stefano", 1)
        j.Add("carlo", 2)
        j.Add("nicola", 3)

        For i As Integer = 0 To j.Count - 1
            Response.Write(j.Keys(i) & ": " & j(i) & "
")
        Next
        Response.Write(j("nicola") & "
")
        Response.Write(j(2) & "
")
    End Sub

    Private Class NameObjectCollection
        Inherits NameObjectCollectionBase

        Public Sub Add(ByVal key As String, ByVal value As Object)
            If Array.IndexOf(Me.BaseGetAllKeys, key) = -1 Then
                Me.BaseAdd(key, value)
            End If

        End Sub

        Public Sub Clear()
            Me.BaseClear()
        End Sub

        Public Sub Remove(ByVal key As String)
            Me.BaseRemove(key)
        End Sub

        Public Sub Remove(ByVal index As Integer)
            Me.BaseRemoveAt(index)
        End Sub

        Default Public Property Item(ByVal key As String)
            Get
                Return Me.BaseGet(key)
            End Get
            Set(ByVal value)
                Me.BaseSet(key, value)
            End Set
        End Property

        Default Public Property Item(ByVal index As Integer)
            Get
                Return Me.BaseGet(index)
            End Get
            Set(ByVal value)
                Me.BaseSet(index, value)
            End Set
        End Property
    End Class
End Class

[pietro09]

questo è un altro tentativo: gliela date una occhiata per vedere se va bene? :master:

Public Class HashtableInsertionOrder
    Inherits DictionaryBase

    Private _al As ArrayList

    Public Sub New()
        Me._al = New ArrayList()
    End Sub

    Public Sub Add(ByVal key As Object, ByVal value As Object)
        If Not (Me.Dictionary.Contains(key)) Then
            Me.Dictionary.Add(key, value)
            Me._al.Add(key)
        Else
            Me.Dictionary("key") = value
        End If
    End Sub

    Public Sub Remove(ByVal key As Object)
        Me.Dictionary.Remove(key)
        Me._al.Remove(key)
    End Sub

    Default Public Property Item(ByVal key As Object) As Object
        Get
            Return Me.Dictionary(key)
        End Get
        Set(ByVal value As Object)
            Me.Dictionary(key) = value
        End Set
    End Property

    Default Public Property Item(ByVal index As Integer) As DictionaryEntry
        Get
            Return New DictionaryEntry(Me._al(index), Me.Dictionary(Me._al(index)))
        End Get
        Set(ByVal value As DictionaryEntry)
            Me.Dictionary(Me._al(index)) = value.Value
        End Set
    End Property


    Public ReadOnly Property Keys() As Object()
        Get
            Return Me._al.ToArray()
        End Get
    End Property

    Public ReadOnly Property Values() As Object()
        Get
            Dim o(Me._al.Count - 1) As Object
            For i As Integer = 0 To Me._al.Count - 1
                o(i) = Me.Dictionary(Me._al(i))
            Next
            Return o
        End Get
    End Property

    Public Sub SortKeys()
        Me._al.Sort()
    End Sub

    Public Sub SortValues()
        Dim k As Object() = Me.Keys()
        Dim v As Object() = Me.Values()
        Array.Sort(v, k)
        Me._al = New ArrayList(k)
    End Sub

End Class

questo per il collaudo

        Dim ht As New HashtableInsertionOrder()
        ht.Add("stefano", 10)
        ht.Add("carlo", 20)
        ht.Add("nicola", 30)
        ht.Add("pietro", 40)
        ht.Add("lucia", 50)

        PrintLn("non ordinato")
        Response.Write("<hr />")
        For Each de As DictionaryEntry In ht
            PrintLn(de.Value, de.Key.ToString())
        Next

        PrintLn()
        PrintLn("ordine di inserimento")
        Response.Write("<hr />")
        For i As Integer = 0 To ht.Count - 1
            PrintLn(ht(i).Value, ht(i).Key.ToString)
        Next


        PrintLn()
        PrintLn("ordine alfabetico delle chiavi")
        Response.Write("<hr />")
        ht.SortKeys()
        For i As Integer = 0 To ht.Count - 1
            PrintLn(ht(i).Value, ht(i).Key.ToString)
        Next

        PrintLn()
        PrintLn("ordine alfabetico dei valori")
        Response.Write("<hr />")
        ht.SortValues()
        For i As Integer = 0 To ht.Count - 1
            PrintLn(ht(i).Value, ht(i).Key.ToString)
        Next

        Response.Write("<hr />")