Creating Literals

You can see the Literal class at work in the Literals example on the CD-ROM. When you click the button in this example, the code inserts the HTML needed to display the word "Hello" in a centered HTML <h1> header—<div align='center'> <h1>Hello</h1></div>—into the Web form, as you can see in Figure 15.10.

Figure 15.10: The Literals example.

Here's Webform1.aspx from the Literals example:

<%@ Page Language="vb" AutoEventWireup="false" Codebehind=
"WebForm1.aspx.vb" Inherits="Literals.WebForm1"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
  <HEAD>
    <title></title>
    <meta name="GENERATOR" content="Microsoft Visual Studio.NET 7.0">
    <meta name="CODE_LANGUAGE" content="Visual Basic 7.0">
    <meta name=vs_defaultClientScript content="JavaScript">
    <meta name=vs_targetSchema
    content="http://schemas.microsoft.com/intellisense/ie5">
  </HEAD>
  <body MS_POSITIONING="GridLayout">

    <form id="Form1" method="post" runat="server">
<asp:Button id=Button1 style="Z-INDEX: 101; LEFT: 96px;
POSITION: absolute; TOP: 106px" runat="server" Text="Click me">
</asp:Button>
<asp:Literal id=Literal1 runat="server"></asp:Literal>

    </form>

  </body>
</HTML>

And here's WebForm1.aspx.vb from the same project:

Public Class WebForm1
    Inherits System.Web.UI.Page
    Protected WithEvents Literal1 As System.Web.UI.WebControls.Literal
    Protected WithEvents Button1 As System.Web.UI.WebControls.Button

#Region " Web Form Designer Generated Code "

    'This call is required by the Web Form Designer.
    <System.Diagnostics.DebuggerStepThrough()> _
        Private Sub InitializeComponent()

    End Sub

    Private Sub Page_Init(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles MyBase.Init
        'CODEGEN: This method call is required by the Web Form Designer
        'Do not modify it using the code editor.
        InitializeComponent()
    End Sub

#End Region

    Private Sub Page_Load(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles MyBase.Load
        'Put user code to initialize the page here
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles Button1.Click
        Literal1.Text = "<div align='center'><h1>Hello</h1></div>"
    End Sub
End Class

Here's how the code inserts the <h1> header when you click the button in this example:

    Private Sub Button1_Click(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles Button1.Click
        Literal1.Text = "<div align='center'><h1>Hello</h1></div>"
    End Sub