Edit

TextBox.TagKey Property

  • Reference

Definition

Namespace:
System.Web.UI.WebControls
Assembly:
System.Web.dll

Gets the HTML tag for the text box control. This property is protected.

protected:
 virtual property System::Web::UI::HtmlTextWriterTag TagKey { System::Web::UI::HtmlTextWriterTag get(); };
protected override System.Web.UI.HtmlTextWriterTag TagKey { get; }
member this.TagKey : System.Web.UI.HtmlTextWriterTag
Protected Overrides ReadOnly Property TagKey As HtmlTextWriterTag

Property Value

HtmlTextWriterTag

Textarea if the text box is multiline; otherwise, Input.

Examples

The following code example demonstrates how to use the TagKey property to create a custom text box.

Important

This example has a text box that accepts user input, which is a potential security threat. By default, ASP.NET Web pages validate that user input does not include script or HTML elements. For more information, see Script Exploits Overview.

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS.Controls" Assembly="Samples.AspNet.CS" %>
<%@ Page Language="C#" AutoEventWireup="True" %>
<!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>
        <title>Custom TextBox - TagKey - C# Example</title>
    </head>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom TextBox - TagKey - C# Example</h3>
            
            <aspSample:CustomTextBoxTagKey 
              id="TextBox1" 
              runat="server">Hello World!
            </aspSample:CustomTextBoxTagKey>
            
        </form>
    </body>
</html>

<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB.Controls" Assembly="Samples.AspNet.VB" %>
<%@ Page Language="VB" AutoEventWireup="True" %>
<!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>
        <title>Custom TextBox - TagKey - VB.NET Example</title>
    </head>
    <body>
        <form id="Form1" method="post" runat="server">
            <h3>Custom TextBox - TagKey - VB.NET Example</h3>
            
            <aspSample:CustomTextBoxTagKey 
              id="TextBox1" 
              runat="server">Hello World!
          </aspSample:CustomTextBoxTagKey>
          
        </form>
    </body>
</html>

using System.Web;
using System.Security.Permissions;

namespace Samples.AspNet.CS.Controls
{
  [AspNetHostingPermission(SecurityAction.Demand, Level=AspNetHostingPermissionLevel.Minimal)]
  public sealed class CustomTextBoxTagKey : System.Web.UI.WebControls.TextBox
  {
    protected override System.Web.UI.HtmlTextWriterTag TagKey
    {
      get 
      {
        // If the TextMode is MultiLine, return a Textarea tag, 
        // else return an Input tag.
        if (this.TextMode == System.Web.UI.WebControls.TextBoxMode.MultiLine)
        {
          return System.Web.UI.HtmlTextWriterTag.Textarea;
        }
        else
        {
          return System.Web.UI.HtmlTextWriterTag.Input;
        }
      }
    }
  }
}

Imports System.Web
Imports System.Security.Permissions

Namespace Samples.AspNet.VB.Controls
    <AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
    Public NotInheritable Class CustomTextBoxTagKey
        Inherits System.Web.UI.WebControls.TextBox

        Protected Overrides ReadOnly Property TagKey() As System.Web.UI.HtmlTextWriterTag
            Get
                ' If the TextMode is MultiLine, return a Textarea tag, else return an Input tag.
                If Me.TextMode = System.Web.UI.WebControls.TextBoxMode.MultiLine Then
                    Return System.Web.UI.HtmlTextWriterTag.Textarea
                Else
                    Return System.Web.UI.HtmlTextWriterTag.Input
                End If
            End Get
        End Property
    End Class
End Namespace

Applies to