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Label Class

.NET Framework 3.5

Represents a label control, which displays text on a Web page.

Namespace:  System.Web.UI.WebControls
Assembly:  System.Web (in System.Web.dll)
C#
C++
JScript
VB
Copy 
[ControlValuePropertyAttribute("Text")]
[AspNetHostingPermissionAttribute(SecurityAction.InheritanceDemand, Level = AspNetHostingPermissionLevel.Minimal)]
[AspNetHostingPermissionAttribute(SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
public class Label : WebControl, ITextControl
ASP.NET
Copy 
<asp:Label />

Use the Label control to display text in a set location on the page. Unlike static text, you can customize the displayed text through the Text property.

You can also use the Literal and PlaceHolder controls to display text on the Web Forms page. However, unlike the Label control, these controls do not render any additional tags.

Security note Security Note:

This control can be used to display 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.

Accessibility

The markup rendered by default for this control might not conform to accessibility standards such as the Web Content Accessibility Guidelines 1.0 (WCAG) priority 1 guidelines. For details about accessibility support for this control, see ASP.NET Controls and Accessibility.

The following example demonstrates how to create a Label control on a Web page.

Note Note:

The following code sample uses the single-file code model and may not work correctly if copied directly into a code-behind file. This code sample must be copied into an empty text file that has an .aspx extension. For more information on the ASP.NET Web page code model, see ASP.NET Web Page Code Model.
Security note Security Note:

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.
C#
VB
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<%@ 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>Label Example</title>
<script language="C#" runat="server">

      void Button_Click(Object Sender, EventArgs e) 
      {
         Label1.Text = Server.HtmlEncode(Text1.Text);
      }

   </script>

</head>

<body>

   <form id="Form1" runat="server">

      <h3>Label Example</h3>

      <asp:Label id="Label1" 
                 Text="Label Control" 
                 runat="server"/>

      <p>

      <asp:TextBox id="Text1" 
           Text="Copy this text to the label"
           Width="200px"  
           runat="server" />

      <asp:Button id="Button1" 
           Text="Copy" 
           OnClick="Button_Click" 
           runat="server"/>
      </p>

   </form>

</body>
</html>
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0
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Security issues

The documentation is badly worded with regards to security.

It states "This control can be used to display 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.".

ASP.NET validation will NOT help you here - only input is validated, not the rendered output of the Label control. It makes it seem as though you're safe including user-generated content in this control.

The contents of an <asp:Label> control are not "HTML Encoded" - if the control is used to display user-generated content (databound or otherwise) without first HTML Encoding it, the page has a serious security problem. Use <asp:Literal Mode="Encode"> instead, if possible.

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