ITブログ時々なんでもブログ

１．改行表示できない原因

２．カスタムコントロールの実装

Option Explicit On
Option Strict On
Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls
<Assembly: TagPrefix("BaseLibrary.Controls", "custom")>
Namespace Controls
    <ToolboxData("<{0}:BaseButton runat=""server"" ID=""BaseButton1"" Text=""""/>")>
    Public Class BaseButton
        Inherits Button

        Private _text As String = String.Empty

        Public Shadows Property Text As String
            Get
                Return _text
            End Get
            Set(value As String)
                _text = value
                MyBase.Text = value
            End Set
        End Property

        Protected Overrides ReadOnly Property TagKey As HtmlTextWriterTag
            Get
                Return HtmlTextWriterTag.Button
            End Get
        End Property

        Protected Overrides Sub AddParsedSubObject(ByVal obj As Object)
            Dim ltrCtrl = DirectCast(obj, LiteralControl)
            If ltrCtrl Is Nothing Then
                Return
            End If

            Me.Text = ltrCtrl.Text

        End Sub

        Protected Overrides Sub RenderContents(ByVal writer As HtmlTextWriter)
            writer.Write(Me.Text)
        End Sub

    End Class

End Namespace

３．ASPX ページへの実装

<%@ Page Language="vb" AutoEventWireup="false" CodeBehind="Test.aspx.vb" Inherits="Test" %>
<%@ Register Assembly="BaseLibrary" Namespace="BaseLibrary.Controls" TagPrefix="custom" %>
<custom:BaseButton ID="BaseButton1" runat="server" Text='OK<br>2行目' CssClass="button enable" />