ICheckBoxControl Interface
Defines the property and event a control implements to act as a check box.
Assembly: System.Web (in System.Web.dll)
| Name | Description | |
|---|---|---|
![]() | Checked | Gets or sets the value of an ICheckBoxControl control that indicates whether the control is selected. |
| Name | Description | |
|---|---|---|
![]() | CheckedChanged | Occurs when the value of the Checked property changes between posts to the server. |
The ICheckBoxControl interface defines the property and event that must be implemented for a control to act as a check box on a Web page. The Checked property can be used to determine whether the check box is selected or to set the property programmatically. The CheckedChanged event is raised when the Checked value changes between posts to the server.
CheckBox implements ICheckBoxControl. The following code example demonstrates how to read the value of the Checked property and respond to a CheckedChanged event.
<%@ 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 runat="server"> <title>CheckBox CheckedChanged Example</title> <script runat="server"> Sub Check_Clicked(sender As Object, e As EventArgs) ' Calculate the subtotal and display the result in currency format. ' Include tax if the check box is selected. Message.Text = CalculateTotal(checkbox1.Checked).ToString("c") End Sub Sub Page_Load(sender As Object, e As EventArgs) ' Display the subtotal without tax when the page is first loaded. If Not IsPostBack Then ' Calculate the subtotal and display the result in currency format. Message.Text = CalculateTotal(false).ToString("c") End If End Sub Function CalculateTotal(Taxable As Boolean) As Double ' Calculate the subtotal for the example. Dim Result As Double = 1.99 + 2.99 + 3.99 ' Add tax, if applicable. If(Taxable) Result += Result * 0.086 End If Return Result End Function </script> </head> <body> <form id="form1" runat="server"> <h3>CheckBox CheckedChanged Example</h3> Select whether to include tax in the subtotal. <br /><br /> <table border="1" cellpadding="5"> <tr> <th colspan="2"> Shopping cart </th> </tr> <tr> <td> Item 1 </td> <td> $1.99 </td> </tr> <tr> <td> Item 2 </td> <td> $2.99 </td> </tr> <tr> <td> Item 3 </td> <td> $3.99 </td> </tr> <tr> <td> <b>Subtotal</b> </td> <td> <asp:Label id="Message" runat="server"/> </td> </tr> <tr> <td colspan="2"> <asp:CheckBox id="checkbox1" runat="server" AutoPostBack="True" Text="Include 8.6% sales tax" TextAlign="Right" OnCheckedChanged="Check_Clicked"/> </td> </tr> </table> </form> </body> </html>
Available since 2.0
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