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HtmlInputRadioButton Class

Allows programmatic access to the HTML <input type= radio> element on the server.

For a list of all members of this type, see HtmlInputRadioButton Members.

System.Object
   System.Web.UI.Control
      System.Web.UI.HtmlControls.HtmlControl
         System.Web.UI.HtmlControls.HtmlInputControl
            System.Web.UI.HtmlControls.HtmlInputRadioButton

[Visual Basic]
Public Class HtmlInputRadioButton
   Inherits HtmlInputControl
   Implements IPostBackDataHandler
[C#]
public class HtmlInputRadioButton : HtmlInputControl,
   IPostBackDataHandler
[C++]
public __gc class HtmlInputRadioButton : public HtmlInputControl,
   IPostBackDataHandler
[JScript]
public class HtmlInputRadioButton extends HtmlInputControl
   implements IPostBackDataHandler

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.

Remarks

Use the HtmlInputRadioButton control to create a radio button on a Web page. The HtmlInputRadioButton control does not provide built-in functionality to display a caption for the radio button. To create a caption, use literal text in the Web page at the desired location. This allows you to control where the caption is displayed relative to the radio button. For example, if you want to display the caption on the right side of the radio button, declare an HtmlInputRadioButton control, followed by the caption text.

<input type="radio" 
 id="Radio1" 
 name="Mode" 
 runat="server"/>
Caption Text<br>

You can optionally associate a quantity with the HtmlInputRadioButton control by setting the Value property. This is useful when you have multiple radio buttons and need to perform a calculation, based on the selection.

HtmlInputRadioButton controls can be grouped together by specifying a common value for the Name property of each radio button you want to include in the group.

Note   When you group HtmlInputRadioButton controls together, only one radio button in the group can be selected at a time.

To determine whether the HtmlInputRadioButton control is selected, test the Checked property. If you have a group of HtmlInputRadioButton controls, you must iterate through the controls and test the Checked property of each control individually.

The HtmlInputRadioButton control provides a ServerChange event that is raised when the Checked property changes values between posts to the server. This allows you to create a custom event handler that performs a specific set of instructions when the event is raised, such as data validation.

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

Example

[Visual Basic, C#, JScript] The following example demonstrates how to use the HtmlInputRadioButton control to create a group of radio buttons.

[Visual Basic] 
<%@ Page Language="VB" AutoEventWireup="True" %>

<html>
<head>

   <script language="VB" runat="server">

    Sub Button1_Click(sender As Object, e As EventArgs)
        
        If Radio1.Checked = True Then
            Span1.InnerHtml = "Option 1 is selected"
        Else
            If Radio2.Checked = True Then
                Span1.InnerHtml = "Option 2 is selected"
            Else
                If Radio3.Checked = True Then
                    Span1.InnerHtml = "Option 3 is selected"
                End If
            End If
        End If
    End Sub 'Button1_Click

   </script>

</head>
<body>

   <form runat=server>

      <h3>HtmlInputRadioButton Sample</h3>

      <input type="radio" 
             id="Radio1" 
             name="Mode" 
             runat="server"/>

      Option 1<br>

      <input type="radio" 
             id="Radio2" 
             name="Mode" 
             runat="server"/>
      
      Option 2<br>

      <input type="radio" 
             id="Radio3" 
             name="Mode" 
             runat="server"/>

      Option 3

      <p>
      <span id="Span1" runat="server" />

      <p>
      <input type="button" 
             id="Button1" 
             value="Enter" 
             OnServerClick="Button1_Click" 
             runat="server">

   </form>

</body>
</html>
   

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

<html>
<head>

   <script language="C#" runat="server">

      void Button1_Click(object sender, EventArgs e) 
      {

         if (Radio1.Checked == true)
            Span1.InnerHtml = "Option 1 is selected";
         else if (Radio2.Checked == true)
            Span1.InnerHtml = "Option 2 is selected";
         else if (Radio3.Checked == true)
            Span1.InnerHtml = "Option 3 is selected";
      }

   </script>

</head>
<body>

   <form runat=server>

      <h3>HtmlInputRadioButton Sample</h3>

      <input type="radio" 
             id="Radio1" 
             name="Mode" 
             runat="server"/>

      Option 1<br>

      <input type="radio" 
             id="Radio2" 
             name="Mode" 
             runat="server"/>
      
      Option 2<br>

      <input type="radio" 
             id="Radio3" 
             name="Mode" 
             runat="server"/>

      Option 3

      <p>
      <span id="Span1" runat="server" />

      <p>
      <input type="button" 
             id="Button1" 
             value="Enter" 
             OnServerClick="Button1_Click" 
             runat="server">

   </form>

</body>
</html>
   

[JScript] 
<%@ Page Language="JScript" AutoEventWireup="True" %>

<html>
<head>

   <script language="JSCRIPT" runat="server">

    function Button1_Click(sender : Object, e : EventArgs){
        
        if(Radio1.Checked)
            Span1.InnerHtml = "Option 1 is selected"
        else if(Radio2.Checked)
            Span1.InnerHtml = "Option 2 is selected"
        else if(Radio3.Checked)
            Span1.InnerHtml = "Option 3 is selected"
    }

   </script>

</head>
<body>

   <form runat=server>

      <h3>HtmlInputRadioButton Sample</h3>

      <input type="radio" 
             id="Radio1" 
             name="Mode" 
             runat="server"/>

      Option 1<br>

      <input type="radio" 
             id="Radio2" 
             name="Mode" 
             runat="server"/>
      
      Option 2<br>

      <input type="radio" 
             id="Radio3" 
             name="Mode" 
             runat="server"/>

      Option 3

      <p>
      <span id="Span1" runat="server" />

      <p>
      <input type="button" 
             id="Button1" 
             value="Enter" 
             OnServerClick="Button1_Click" 
             runat="server">

   </form>

</body>
</html>
   

[C++] No example is available for C++. To view a Visual Basic, C#, or JScript example, click the Language Filter button Language Filter in the upper-left corner of the page.

Requirements

Namespace: System.Web.UI.HtmlControls

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

Assembly: System.Web (in System.Web.dll)

See Also

HtmlInputRadioButton Members | System.Web.UI.HtmlControls Namespace | Name | Value | Checked | ServerChange | HtmlInputCheckBox

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