Web複合コントロールのデザイン時の表示について

protected override void OnLoad(EventArgs e) {
	base.EnsureChildControls();
	base.OnLoad (e);
}

Public Class ccTextDesigner
    Inherits System.Web.UI.Design.ControlDesigner

    Public Overrides Function GetDesignTimeHtml() As String

        Dim ctl As ccText = CType(Me.Component, ccText)
        Dim sw As New StringWriter
        Dim tw As New HtmlTextWriter(sw)

        Dim _txt As TextBox
        Dim _hl As HyperLink

        '入力テキスト
        _txt = New TextBox
        _txt.Text = ctl.Text
        _txt.Width = ctl.TextWidth
        _txt.CssClass = ctl.CssClassText
        _txt.Enabled = ctl.Enabled
        _txt.RenderControl(tw)

        'ハイパーリンク
        If ctl.HyperLinkVisible Then
            _hl = New HyperLink
            _hl.Text = ctl.HyperlinkTextForDesigner
            _hl.NavigateUrl = ctl.HyperlinkNavigateUrl
            _hl.CssClass = ctl.CssClassHyperlink
            _hl.RenderControl(tw)
        End If

        Return sw.ToString()

    End Function

End Class

    Dim ctl As ccText = CType(Me.Component, ccText)
    Dim sw As New StringWriter
    Dim tw As New HtmlTextWriter(sw)

    ctl.RenderControl(tw)

    Return sw.ToString()

<DefaultEvent("Click"), _
 DefaultProperty("Text")> _
Public Class NonDesignerCustomControl
    Inherits System.Web.UI.WebControls.WebControl
    Implements INamingContainer

    ' 子コントロール描画
    Protected Overrides Sub RenderContents(ByVal writer As System.Web.UI.HtmlTextWriter)
        MyBase.EnsureChildControls()
        MyBase.RenderContents(writer)
    End Sub

    ' 公開用イベント
    <Browsable(True)> _
    Public Event Click As EventHandler

    ' イベント処理
    Protected Overridable Sub OnClick(ByVal source As Object, ByVal e As EventArgs)
        Text = "押された"
        RaiseEvent Click(source, e)
    End Sub

    Private Sub Button1_Click(ByVal source As Object, ByVal e As EventArgs)
        OnClick(source, e)
    End Sub

    ' 子コントロール追加
    Protected Overrides Sub CreateChildControls()
        Controls.Add(New LiteralControl("<h2>"))

        Dim Label1 As New System.Web.UI.WebControls.Label
        Label1.Text = "入力→"
        Controls.Add(Label1)

        Dim TextBox1 As New System.Web.UI.WebControls.TextBox
        TextBox1.Text = "999"
        Controls.Add(TextBox1)

        Dim Button1 As New System.Web.UI.WebControls.Button
        Button1.Text = "押す"
        AddHandler Button1.Click, AddressOf Button1_Click
        Controls.Add(Button1)

        Controls.Add(New LiteralControl("</h2>"))
    End Sub

    ' 公開用プロパティ
    <Browsable(True)> _
    Public Property Text() As String
        Get
            Return DirectCast(Controls(2), System.Web.UI.WebControls.TextBox).Text
        End Get
        Set(ByVal Value As String)
            DirectCast(Controls(2), System.Web.UI.WebControls.TextBox).Text = Value
        End Set
    End Property

End Class