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TextBox.TextBox Constructor

Initializes a new instance of the TextBox class.

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

public TextBox ()
public TextBox ()
public function TextBox ()
Not applicable.

Use this constructor to create and initialize a new instance of the TextBox class.

The following table shows the initial property value for an instance of TextBox.


Initial value



The following code example demonstrates how to use the TextBox constructor to dynamically add a TextBox control to the page.

Security noteSecurity 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 (Visual Studio).

<%@ Page Language="C#" AutoEventWireup="True" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
<html xmlns="" > 

    <title> TextBox Constructor Example </title>
<script runat="server">

      protected void Page_Load(Object sender, EventArgs e)

         // Create UserTextBox TextBox control.
         TextBox UserTextBox = new TextBox();

         // Configure the UserTextBox TextBox control.
         UserTextBox.ID = "UserTextBox";
         UserTextBox.Columns = 50;

         // Add UserTextBox TextBox control to the Controls collection 
         // of the TextBoxControlPlaceHolder PlaceHolder control.


      protected void Submit_Click(Object sender, EventArgs e)

         // Retrieve the UserTextBox TextBox control from the TextBoxControlPlaceHolder
         // PlaceHolder control.
         TextBox TempTextBox = (TextBox)TextBoxControlPlaceHolder.FindControl("UserTextBox");

         // Display the Text property.
         Message.Text = "The TextBox control above is dynamically generated. <br /> You entered: " + 





   <form id="form1" runat="server">

      <h3> TextBox Constructor Example </h3>

      Enter some text and click the Submit button. <br /><br />

      <asp:PlaceHolder ID="TextBoxControlPlaceHolder"

      <br /><br />
      <asp:Button ID="SubmitButton"

      <br /><br />

      <asp:Label ID="Message"



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