TextBox Class (System.Web.UI.WebControls)

TextBox Class

.NET Framework Class Library

TextBox Class

Displays a text box control for user input.

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

Syntax

Visual Basic (Declaration)

<ValidationPropertyAttribute("Text")> _
<ControlValuePropertyAttribute("Text")> _
<AspNetHostingPermissionAttribute(SecurityAction.LinkDemand, Level := AspNetHostingPermissionLevel.Minimal)> _
<AspNetHostingPermissionAttribute(SecurityAction.InheritanceDemand, Level := AspNetHostingPermissionLevel.Minimal)> _
Public Class TextBox _
    Inherits WebControl _
    Implements IPostBackDataHandler, IEditableTextControl, ITextControl

Visual Basic (Usage)

Dim instance As TextBox

[ValidationPropertyAttribute("Text")]
[ControlValuePropertyAttribute("Text")]
[AspNetHostingPermissionAttribute(SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
[AspNetHostingPermissionAttribute(SecurityAction.InheritanceDemand, Level = AspNetHostingPermissionLevel.Minimal)]
public class TextBox : WebControl, IPostBackDataHandler, 
    IEditableTextControl, ITextControl

Visual C++

[ValidationPropertyAttribute(L"Text")]
[ControlValuePropertyAttribute(L"Text")]
[AspNetHostingPermissionAttribute(SecurityAction::LinkDemand, Level = AspNetHostingPermissionLevel::Minimal)]
[AspNetHostingPermissionAttribute(SecurityAction::InheritanceDemand, Level = AspNetHostingPermissionLevel::Minimal)]
public ref class TextBox : public WebControl, 
    IPostBackDataHandler, IEditableTextControl, ITextControl

JScript

public class TextBox extends WebControl implements IPostBackDataHandler, IEditableTextControl, ITextControl

ASP.NET

<asp:TextBox />

Remarks

The TextBox server control is an input control that lets the user enter text. By default, the TextMode property of the control is set to TextBoxMode.SingleLine, which displays a single-line text box. However, you can also use the TextBox control to display a multiline text box or a text box that masks user input by changing the value of the TextMode property to TextBoxMode.MultiLine or TextBoxMode.Password, respectively. The text displayed in the TextBox control is specified or determined by using the Text property.

The TextBox control contains several properties that allow you to control the appearance of the control. The display width of the text box, in characters, is determined by its Columns property. If the TextBox control is a multiline text box, the number of rows it displays is determined by the Rows property. To display text that wraps within the TextBox control, set the Wrap property to true.

You can also specify how data is entered in the TextBox control by setting a few properties. To prevent the text displayed in the control from being modified, set the ReadOnly property to true. If you want to limit the user input to a specified number of characters, set the MaxLength property.

For a list of initial property values for an instance of TextBox, see the TextBox constructor.

Caution:
This control can be used to accept user input, which might include malicious client script. Check any information that is sent from a client for executable script, SQL statements, or other code before displaying it in your application. You can use validation controls to verify user input before displaying the input text in a control. ASP.NET provides an input request validation feature to block script and HTML in user input. For more information, see Securing Standard Controls, How to: Protect Against Script Exploits in a Web Application by Applying HTML Encoding to Strings, and Validating User Input in ASP.NET Web Pages.

Caution:

This control can be used to accept user input, which might include malicious client script. Check any information that is sent from a client for executable script, SQL statements, or other code before displaying it in your application. You can use validation controls to verify user input before displaying the input text in a control. ASP.NET provides an input request validation feature to block script and HTML in user input. For more information, see Securing Standard Controls, How to: Protect Against Script Exploits in a Web Application by Applying HTML Encoding to Strings, and Validating User Input in ASP.NET Web Pages.

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.

Topic	Location
How to: Get and Set Values in TextBox Web Server Controls	Building ASP .NET Web Applications
How to: Get and Set Values in TextBox Web Server Controls	Building ASP .NET Web Applications
How to: Get and Set Values in TextBox Web Server Controls	Building ASP .NET Web Applications in Visual Studio
How to: Get and Set Values in TextBox Web Server Controls	Building ASP .NET Web Applications in Visual Studio
How to: Protect Against Script Exploits in a Web Application by Applying HTML Encoding to Strings	Building ASP .NET Web Applications
How to: Protect Against Script Exploits in a Web Application by Applying HTML Encoding to Strings	Building ASP .NET Web Applications
How to: Protect Against Script Exploits in a Web Application by Applying HTML Encoding to Strings	Building ASP .NET Web Applications in Visual Studio
How to: Protect Against Script Exploits in a Web Application by Applying HTML Encoding to Strings	Building ASP .NET Web Applications in Visual Studio
How to: Respond to Changes in a TextBox Web Server Control	Building ASP .NET Web Applications
How to: Respond to Changes in a TextBox Web Server Control	Building ASP .NET Web Applications
How to: Respond to Changes in a TextBox Web Server Control	Building ASP .NET Web Applications in Visual Studio
How to: Respond to Changes in a TextBox Web Server Control	Building ASP .NET Web Applications in Visual Studio
How to: Set a TextBox Web Server Control for Password Entry	Building ASP .NET Web Applications
How to: Set a TextBox Web Server Control for Password Entry	Building ASP .NET Web Applications
How to: Set a TextBox Web Server Control for Password Entry	Building ASP .NET Web Applications in Visual Studio
How to: Set a TextBox Web Server Control for Password Entry	Building ASP .NET Web Applications in Visual Studio
How to: Set ASP.NET Web Server Control Properties	Building ASP .NET Web Applications
How to: Set ASP.NET Web Server Control Properties	Building ASP .NET Web Applications
How to: Set ASP.NET Web Server Control Properties	Building ASP .NET Web Applications in Visual Studio
How to: Set ASP.NET Web Server Control Properties	Building ASP .NET Web Applications in Visual Studio
How to: Set Focus on ASP.NET Web Server Controls	Building ASP .NET Web Applications
How to: Set Focus on ASP.NET Web Server Controls	Building ASP .NET Web Applications
How to: Set Focus on ASP.NET Web Server Controls	Building ASP .NET Web Applications in Visual Studio
How to: Set Focus on ASP.NET Web Server Controls	Building ASP .NET Web Applications in Visual Studio
How to: Specify Multiline Input for a TextBox Web Server Control	Building ASP .NET Web Applications
How to: Specify Multiline Input for a TextBox Web Server Control	Building ASP .NET Web Applications
How to: Specify Multiline Input for a TextBox Web Server Control	Building ASP .NET Web Applications in Visual Studio
How to: Specify Multiline Input for a TextBox Web Server Control	Building ASP .NET Web Applications in Visual Studio
Walkthrough: Creating a Basic Web Page in Visual Web Developer	Building ASP .NET Web Applications in Visual Studio
Walkthrough: Creating a Basic Web Page in Visual Web Developer	Building ASP .NET Web Applications in Visual Studio
Walkthrough: Creating a Basic Web Page in Visual Web Developer	Building ASP .NET Web Applications in Visual Studio
Walkthrough: Creating and Using ASP.NET Master Pages in Visual Web Developer	Building ASP .NET Web Applications in Visual Studio
Walkthrough: Creating and Using ASP.NET Master Pages in Visual Web Developer	Building Applications with Visual Web Developer
Walkthrough: Creating and Using ASP.NET Master Pages in Visual Web Developer	Building ASP .NET Web Applications in Visual Studio
Walkthrough: Data Binding to a Custom Business Object	Building ASP .NET Web Applications in Visual Studio
Walkthrough: Data Binding to a Custom Business Object	Building ASP .NET Web Applications in Visual Studio
Walkthrough: Data Binding to a Custom Business Object	Building ASP .NET Web Applications in Visual Studio
Walkthrough: Validating User Input in a Web Forms Page	Building ASP .NET Web Applications in Visual Studio
Walkthrough: Validating User Input in a Web Forms Page	Building Applications with Visual Web Developer
Walkthrough: Validating User Input in a Web Forms Page	Building ASP .NET Web Applications in Visual Studio
Walkthrough: Working with Cascading Style Sheet Styles in Visual Web Developer	Building ASP .NET Web Applications in Visual Studio

Examples

The following code example demonstrates how to use the TextBox control to get user input. When the user clicks the Add button, the sum of the values entered in the text boxes is displayed.

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.

Visual Basic

<%@ 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  > 

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

      Protected Sub AddButton_Click(sender As Object, e As EventArgs)

         Dim Answer As Integer

         Answer = Convert.ToInt32(Value1.Text) + Convert.ToInt32(Value2.Text)

         AnswerMessage.Text = Answer.ToString()

      End Sub

   </script>

</head>

<body>

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

      <h3> TextBox Example </h3>

      <table>

         <tr>

            <td colspan="5">

               Enter integer values into the text boxes. <br />
               Click the Add button to add the two values. <br />
               Click the Reset button to reset the text boxes.

            </td>

         </tr>

         <tr>

            <td colspan="5">

               &nbsp;

            </td>

         </tr>

         <tr align="center">

            <td>

               <asp:TextBox ID="Value1"
                    Columns="2"
                    MaxLength="3"
                    Text="1"
                    runat="server"/>

            </td>

            <td>

               + 

            </td>

            <td>

               <asp:TextBox ID="Value2"
                    Columns="2"
                    MaxLength="3"
                    Text="1"
                    runat="server"/>

            </td>

            <td>

               =

            </td>

            <td>

               <asp:Label ID="AnswerMessage"
                    runat="server"/>

            </td>

         </tr>

         <tr>

            <td colspan="2">

               <asp:RequiredFieldValidator
                    ID="Value1RequiredValidator"
                    ControlToValidate="Value1"
                    ErrorMessage="Please enter a value.<br />"
                    Display="Dynamic"
                    runat="server"/>

               <asp:RangeValidator
                    ID="Value1RangeValidator"
                    ControlToValidate="Value1"
                    Type="Integer"
                    MinimumValue="1"
                    MaximumValue="100"
                    ErrorMessage="Please enter an integer <br /> between than 1 and 100.<br />"
                    Display="Dynamic"
                    runat="server"/>

            </td>

            <td colspan="2">

               <asp:RequiredFieldValidator
                    ID="Value2RequiredValidator"
                    ControlToValidate="Value2"
                    ErrorMessage="Please enter a value.<br />"
                    Display="Dynamic"
                    runat="server"/>

               <asp:RangeValidator
                    ID="Value2RangeValidator"
                    ControlToValidate="Value2"
                    Type="Integer"
                    MinimumValue="1"
                    MaximumValue="100"
                    ErrorMessage="Please enter an integer <br /> between than 1 and 100.<br />"
                    Display="Dynamic"
                    runat="server"/>

            </td>

            <td>

               &nbsp

            </td>

         </tr>

         <tr align="center">

            <td colspan="4">

               <asp:Button ID="AddButton"
                    Text="Add"
                    OnClick="AddButton_Click"
                    runat="server"/>

            </td>

            <td>

               &nbsp;

            </td>

         </tr>

      </table>

   </form>

</body>
</html>

<%@ 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  > 

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

      protected void AddButton_Click(Object sender, EventArgs e)
      {
         int Answer;

         Answer = Convert.ToInt32(Value1.Text) + Convert.ToInt32(Value2.Text);

         AnswerMessage.Text = Answer.ToString();

      }

   </script>

</head>

<body>

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

      <h3> TextBox Example </h3>

      <table>

         <tr>

            <td colspan="5">

               Enter integer values into the text boxes. <br />
               Click the Add button to add the two values. <br />
               Click the Reset button to reset the text boxes.

            </td>

         </tr>

         <tr>

            <td colspan="5">

               &nbsp;

            </td>

         </tr>

         <tr align="center">

            <td>

               <asp:TextBox ID="Value1"
                    Columns="2"
                    MaxLength="3"
                    Text="1"
                    runat="server"/>

            </td>

            <td>

               + 

            </td>

            <td>

               <asp:TextBox ID="Value2"
                    Columns="2"
                    MaxLength="3"
                    Text="1"
                    runat="server"/>

            </td>

            <td>

               =

            </td>

            <td>

               <asp:Label ID="AnswerMessage"
                    runat="server"/>

            </td>

         </tr>

         <tr>

            <td colspan="2">

               <asp:RequiredFieldValidator
                    ID="Value1RequiredValidator"
                    ControlToValidate="Value1"
                    ErrorMessage="Please enter a value.<br />"
                    Display="Dynamic"
                    runat="server"/>

               <asp:RangeValidator
                    ID="Value1RangeValidator"
                    ControlToValidate="Value1"
                    Type="Integer"
                    MinimumValue="1"
                    MaximumValue="100"
                    ErrorMessage="Please enter an integer <br /> between than 1 and 100.<br />"
                    Display="Dynamic"
                    runat="server"/>

            </td>

            <td colspan="2">

               <asp:RequiredFieldValidator
                    ID="Value2RequiredValidator"
                    ControlToValidate="Value2"
                    ErrorMessage="Please enter a value.<br />"
                    Display="Dynamic"
                    runat="server"/>

               <asp:RangeValidator
                    ID="Value2RangeValidator"
                    ControlToValidate="Value2"
                    Type="Integer"
                    MinimumValue="1"
                    MaximumValue="100"
                    ErrorMessage="Please enter an integer <br /> between than 1 and 100.<br />"
                    Display="Dynamic"
                    runat="server"/>

            </td>

            <td>

               &nbsp

            </td>

         </tr>

         <tr align="center">

            <td colspan="4">

               <asp:Button ID="AddButton"
                    Text="Add"
                    OnClick="AddButton_Click"
                    runat="server"/>

            </td>

            <td>

               &nbsp;

            </td>

         </tr>

      </table>

   </form>

</body>
</html>

.NET Framework Security

AspNetHostingPermission
for operating in a hosted environment. Demand value: LinkDemand; Permission value: Minimal.
AspNetHostingPermission
for operating in a hosted environment. Demand value: InheritanceDemand; Permission value: Minimal.

Inheritance Hierarchy

System..::.Object
  System.Web.UI..::.Control
    System.Web.UI.WebControls..::.WebControl
      System.Web.UI.WebControls..::.TextBox

Thread Safety

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

Platforms

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.

Version Information

.NET Framework

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

Reference

TextBox Members

System.Web.UI.WebControls Namespace

Other Resources

TextBox Web Server Control Overview

Script Exploits Overview