[VB.NET]ドロップダウンリストで初期表示を未選択状態にする

Option Strict On

Public Class WebForm1
    Inherits System.Web.UI.Page

[ Web フォーム デザイナで生成されたコード ]

    Private Sub Button1_Click(...) Handles Button1.Click
        Dim hItems As New System.Collections.ArrayList()

        hItems.Add(New Person(Nothing, Nothing))
        hItems.Add(New Person("N00001", "中博俊"))
        hItems.Add(New Person("J00001", "じゃんぬ"))
        hItems.Add(New Person("J00002", "Jitta"))
        hItems.Add(New Person("T00001", "trapemiya"))
        hItems.Add(New Person("K00001", "夏椰"))
        hItems.Add(New Person("M00001", "まゆりん"))
        hItems.Add(New Person("N00001", "なおこ (･∀･)"))

        Me.DropDownList1.DataSource = hItems
        Me.DropDownList1.DataValueField = "Code"
        Me.DropDownList1.DataTextField = "Name"
        Me.DropDownList1.DataBind()
    End Sub

End Class

Public Class Person

  #Region "　コンストラクタ　"

    Public Sub New(ByVal code As String, ByVal name As String)
        _Code = code
        _Name = name
    End Sub

  #End Region

  #Region "　Code プロパティ　"

    Private _Code As String

    Public ReadOnly Property Code() As String
        Get
            Return _Code
        End Get
    End Property

  #End Region

  #Region "　Name プロパティ　"

    Private _Name As String

    Public ReadOnly Property Name() As String
        Get
            Return _Name
        End Get
    End Property

  #End Region

End Class