Using For Each with a Hashtable's default IEnumerator implementation (VB) : Hashtable « Collections « ASP.NET Tutorial






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<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default.aspx.vb" Inherits="_Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    
    </div>
    </form>
</body>
</html>

File: Default.aspx.vb

Imports System
Imports System.Collections
Imports Microsoft.VisualBasic

Public Class Person
    Implements IComparable
    Dim FirstName As String
    Dim LastName As String

    Public Sub New(ByVal First As String, ByVal Last As String)
        FirstName = First
        LastName = Last
    End Sub

    Public ReadOnly Property FullName() As String
        Get
            Return FirstName & " " & LastName
        End Get
    End Property

    Public Function CompareTo(ByVal obj As Object) _
        As Integer Implements IComparable.CompareTo

        If Not TypeOf (obj) Is Person Then
            Throw New ArgumentException("Object is not a Person!")
        End If

        Dim p2 As Person = CType(obj, Person)
        Dim lastNameResult As Integer = Me.LastName.CompareTo(p2.LastName)

        If lastNameResult = 0 Then
            Dim firstNameResult As Integer = Me.FirstName.CompareTo(p2.FirstName)
            Return firstNameResult
        Else
            Return lastNameResult
        End If
    End Function

End Class

Partial Class _Default
    Inherits System.Web.UI.Page

    Protected Sub Page_Load(ByVal sender As Object, _
            ByVal e As System.EventArgs) Handles Me.Load

        Dim scott As New Person("A", "B")
        Dim bill As New Person("C", "D")
        Dim srini As New Person("E", "F")

        Dim peopleHashtable As New Hashtable()
        peopleHashtable.Add("sh", scott)
        peopleHashtable.Add("be", bill)
        peopleHashtable.Add("ss", srini)

        Dim found As Person = CType(peopleHashtable("sh"), Person)
        Response.Write(found.FullName & "<BR/>")
        found = CType(peopleHashtable("be"), Person)
        Response.Write(found.FullName & "<BR/>")
        found = CType(peopleHashtable("sh"), Person)
        Response.Write(found.FullName & "<BR/>")

        For Each de As DictionaryEntry In peopleHashtable
            Response.Write(de.Key.ToString() & ":" & CType(de.Value, Person).FullName & _
               "<BR/>")
        Next
    End Sub
End Class








7.5.Hashtable
7.5.1.Hashtable collection
7.5.2.Retrieving Person objects from a Hashtable (C#)
7.5.3.Retrieving Person objects from a Hashtable (VB)
7.5.4.Using For Each with a Hashtable's default IEnumerator implementation (C#)
7.5.5.Using For Each with a Hashtable's default IEnumerator implementation (VB)
7.5.6.Using For Each with a Hashtable's Keys and Values member collections (C#)
7.5.7.Using For Each with a Hashtable's Keys and Values member collections (VB)