TextBox.ReadOnly Property
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Gets or sets a value indicating whether the contents of the TextBox control can be changed.
public:
virtual property bool ReadOnly { bool get(); void set(bool value); };[System.ComponentModel.Bindable(true)]
public virtual bool ReadOnly { get; set; }[System.ComponentModel.Bindable(true)]
[System.Web.UI.Themeable(false)]
public virtual bool ReadOnly { get; set; }[<System.ComponentModel.Bindable(true)>]
member this.ReadOnly : bool with get, set[<System.ComponentModel.Bindable(true)>]
[<System.Web.UI.Themeable(false)>]
member this.ReadOnly : bool with get, setPublic Overridable Property ReadOnly As BooleanProperty Value
true if the contents of the TextBox control cannot be changed; otherwise, false. The default value is false.
- Attributes
Examples
The following code example demonstrates how to use the ReadOnly property to prevent any changes to the text displayed in the TextBox control.
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.
<%@ 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> MultiLine TextBox Example </title>
<script runat="server">
protected void SubmitButton_Click(Object sender, EventArgs e)
{
Message.Text = "Thank you for your comment: <br />" + Comment.Text;
}
protected void Check_Change(Object sender, EventArgs e)
{
Comment.Wrap = WrapCheckBox.Checked;
Comment.ReadOnly = ReadOnlyCheckBox.Checked;
}
</script>
</head>
<body>
<form id="form1" runat="server">
<h3> MultiLine TextBox Example </h3>
Please enter a comment and click the submit button.
<br /><br />
<asp:TextBox ID="Comment"
TextMode="MultiLine"
Columns="50"
Rows="5"
runat="server"/>
<br />
<asp:RequiredFieldValidator
ID="Value1RequiredValidator"
ControlToValidate="Comment"
ErrorMessage="Please enter a comment.<br />"
Display="Dynamic"
runat="server"/>
<asp:CheckBox ID="WrapCheckBox"
Text="Wrap Text"
Checked="True"
AutoPostBack="True"
OnCheckedChanged="Check_Change"
runat="server"/>
<asp:CheckBox ID="ReadOnlyCheckBox"
Text="ReadOnly"
Checked="False"
AutoPostBack="True"
OnCheckedChanged="Check_Change"
runat="server"/>
<asp:Button ID="SubmitButton"
Text="Submit"
OnClick="SubmitButton_Click"
runat="server"/>
<hr />
<asp:Label ID="Message"
runat="server"/>
</form>
</body>
</html>
<%@ 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> MultiLine TextBox Example </title>
<script runat="server">
Protected Sub SubmitButton_Click(sender As Object, e As EventArgs )
Message.Text = "Thank you for your comment: <br />" + Comment.Text
End Sub
Protected Sub Check_Change(sender As Object, e As EventArgs )
Comment.Wrap = WrapCheckBox.Checked
Comment.ReadOnly = ReadOnlyCheckBox.Checked
End Sub
</script>
</head>
<body>
<form id="form1" runat="server">
<h3> MultiLine TextBox Example </h3>
Please enter a comment and click the submit button.
<br /><br />
<asp:TextBox ID="Comment"
TextMode="MultiLine"
Columns="50"
Rows="5"
runat="server"/>
<br />
<asp:RequiredFieldValidator
ID="Value1RequiredValidator"
ControlToValidate="Comment"
ErrorMessage="Please enter a comment.<br />"
Display="Dynamic"
runat="server"/>
<asp:CheckBox ID="WrapCheckBox"
Text="Wrap Text"
Checked="True"
AutoPostBack="True"
OnCheckedChanged="Check_Change"
runat="server"/>
<asp:CheckBox ID="ReadOnlyCheckBox"
Text="ReadOnly"
Checked="False"
AutoPostBack="True"
OnCheckedChanged="Check_Change"
runat="server"/>
<asp:Button ID="SubmitButton"
Text="Submit"
OnClick="SubmitButton_Click"
runat="server"/>
<hr />
<asp:Label ID="Message"
runat="server"/>
</form>
</body>
</html>
Remarks
Use the ReadOnly property to specify whether the contents of the TextBox control can be changed. Setting this property to true will prevent users from entering a value or changing the existing value. Note that the user of the TextBox control cannot change this property; only the developer can.
Important
The Text value of a TextBox control with the ReadOnly property set to true is sent to the server when a postback occurs, but the server does no processing for a read-only text box. This prevents a malicious user from changing a Text value that is read-only. The value of the Text property is preserved in the view state between postbacks unless modified by server-side code.
This property cannot be set by themes or style sheet themes. For more information, see ThemeableAttribute and ASP.NET Themes and Skins.
