HtmlForm.UniqueID Property

Gets the unique programmatic identifier assigned to the HtmlForm control.

Namespace: System.Web.UI.HtmlControls
Assembly: System.Web (in system.web.dll)

public override string UniqueID { get; }
/** @property */
public String get_UniqueID ()

public override function get UniqueID () : String

Not applicable.

Property Value

The unique programmatic identifier assigned to the HtmlForm control.

Use the UniqueID property to get the unique programmatic identifier assigned to the HtmlForm control. This property overrides the base implementation to return a constant value when the control is contained in an INamingContainer-implemented object other than a page, such as a custom server control. If the naming container is a page, the value of the HtmlForm control's ID property is returned.

The UniqueID property and the Name property always return the same value. This is useful when the HtmlForm control is rendered on a browser that requires the HtmlForm control's UniqueID and Name properties to be the same. To keep these properties synchronized, the Name property always returns the value of the UniqueID property.


The name attribute is not an XHTML-compliant attribute and by default is not rendered by ASP.NET. For more information on configuring ASP.NET for non-XHTML rendering, see How to: Configure ASP.NET Web Sites for Non-XHTML Rendering.

The following code example demonstrates how to use the UniqueID property to retrieve the unique identifier for an HtmlForm control.

<%@ page language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
<script runat="Server">
  void Button1_Click(object sender, System.EventArgs e)
    // Write the form's UniqueID to the specified Label control.
    Label1.Text = "The HtmlForm control's UniqueID is "
                  + Form1.UniqueID + ".";

  void Button2_Click(object sender, System.EventArgs e)
    // Write the button's UniqueID to the specified Label control.
    Label2.Text = "This Button control's UniqueID is "
                 + Button2.UniqueID + ".";

<html xmlns="" >


    <title>HtmlForm UniqueID Property Example</title>



    <form id="Form1"
    <h3>HtmlForm UniqueID Property Example</h3>        
    <asp:button id="Button1"
                text="Get the form's UniqueID" 
    <asp:label id="Label1"
    <br />
    <asp:button id="Button2" 
                text="Get this button's UniqueID"

    <asp:label id="Label2"



Windows 98, Windows Server 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

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