Gets or sets a value indicating whether the Web server control is enabled.
Assembly: System.Web (in System.Web.dll)
When the property of a control is set to false, the control typically appears dimmed. If the control is an input element, the browser prevents the user from clicking or typing in it. HTML elements that are rendered for a server control are marked as disabled by setting their disabled attribute or their CSS class attribute. For more information, see SupportsDisabledAttribute and ControlRenderingCompatibilityVersion.
This property propagates down the control hierarchy. If you disable a container control, the child controls within that container are also disabled. For more information, see the IsEnabled property.
In a custom composite control, this inheritance behavior does not apply to controls that have not yet created their child controls. You must either set the enabled state of the child controls when they are created, or override the property to call the EnsureChildControls method.
Disabling a control only prevents interaction with the control by the user through the browser UI. It is possible for a user to craft a request that submits a postback that is processed by the page even if controls on the page are disabled. Before you process a postback request, check to make sure that the control is enabled and visible.
Not all controls support this property. See the individual controls for details.
|Walkthrough: Validating User Input in a Web Forms Page||Building ASP .NET Web Applications in Visual Studio|
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 Web Forms code model, see ASP.NET Web Forms Page Code Model.
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="VB" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <script runat="server"> Sub SubmitBtn1_Click(ByVal sender As Object, ByVal e As EventArgs) TextBox1.Enabled = Not (TextBox1.Enabled) End Sub </script> <html xmlns="http://www.w3.org/1999/xhtml" > <head id="Head2" runat="server"> <title>Enabled Property Example</title> </head> <body> <form id="form1" runat="server"> <div> <h3>Enabled Property of a Web Control</h3> <p> <asp:TextBox id="TextBox1" BackColor="LightBlue" runat="server">Light Blue</asp:TextBox> </p> <p> <asp:TextBox id="TextBox2" BackColor="LightGreen" runat="server">Light Green</asp:TextBox> </p> <asp:Button id="SubmitBtn1" runat="server" Text="Click to disable or enable the light blue text box" OnClick="SubmitBtn1_Click" /> </div> </form> </body> </html>