Flex - RadioButton Control

Introduction

The RadioButton control allows the user make a single choice within a set of mutually exclusive choices.

Class Declaration

Following is the declaration for spark.components.RadioButton class −

public class RadioButton 
   extends ToggleButtonBase
      implements IFocusManagerGroup

Public Properties

Sr.No	Properties & Description
1	enabled : Boolean [override] The RadioButton component is enabled if the RadioButtonGroup is enabled and the RadioButton itself is enabled.
2	group : RadioButtonGroup The RadioButtonGroup component to which this RadioButton belongs.
3	groupName : String Specifies the name of the group to which this RadioButton component belongs, or specifies the value of the id property of a RadioButtonGroup component if this RadioButton is part of a group defined by a RadioButtonGroup component.
4	value : Object Optional user-defined value that is associated with a RadioButton component.

Public Methods

Sr.No	Method & Description
1	RadioButton() Constructor.

Methods Inherited

This class inherits methods from the following classes −

spark.components.supportClasses.ToggleButtonBase
spark.components.supportClasses.ButtonBase
spark.components.supportClasses.SkinnableComponent
mx.core.UIComponent
mx.core.FlexSprite
flash.display.Sprite
flash.display.DisplayObjectContainer
flash.display.InteractiveObject
flash.display.DisplayObject
flash.events.EventDispatcher
Object

Flex RadioButton Control Example

Let us follow the following steps to check usage of RadioButton control in a Flex application by creating a test application −

Step	Description
1	Create a project with a name HelloWorld under a packagecom.tutorialspoint.client as explained in the Flex - Create Application chapter.
2	Modify HelloWorld.mxml as explained below. Keep rest of the files unchanged.
3	Compile and run the application to make sure business logic is working as per the requirements.

Following is the content of the modified mxml file src/com.tutorialspoint/HelloWorld.mxml.

<?xml version = "1.0" encoding = "utf-8"?>
<s:Application xmlns:fx = "http://ns.adobe.com/mxml/2009"
   xmlns:s = "library://ns.adobe.com/flex/spark"
   xmlns:mx = "library://ns.adobe.com/flex/mx"
   width = "100%" height = "100%" minWidth = "500" minHeight = "500">
   
   <fx:Style source = "/com/tutorialspoint/client/Style.css" />
   <fx:Script>
      <![CDATA[
         [Bindable]
         private var selectedOption:String = "";
         protected function option_clickHandler(event:MouseEvent):void {
            var radioButton:RadioButton = event.target as RadioButton;
            switch (radioButton.id) {
               case option1.id:
                  selectedOption = option1.label;
                  break;
               case option2.id:
                  selectedOption = option2.label;
                  break;
               case option3.id:
                  selectedOption = option3.label;
                  break;
               case option4.id:
                  selectedOption = option4.label;
                  break;
            }			
         }
      ]]>
   </fx:Script>
   
   <s:BorderContainer width = "550" height = "400" id = "mainContainer" 
      styleName = "container">
      <s:VGroup width = "100%" height = "100%" gap = "50" 
         horizontalAlign = "center" verticalAlign = "middle">
         <s:Label id = "lblHeader" text = "Form Controls Demonstration" 
            fontSize = "40" color = "0x777777" styleName = "heading" />
         
         <s:Panel id = "radioButtonPanel" title = "Using RadioButton" 
            width = "420" height = "200" >
            <s:layout>
               <s:VerticalLayout  gap = "10" verticalAlign = "middle"
                  horizontalAlign = "center" />	
            </s:layout>
            
            <s:RadioButton groupName = "options" id = "option1" 
               label = "item #1" width="150" 
               click = "option_clickHandler(event)" />
            <s:RadioButton groupName = "options" id = "option2" 
               label = "item #2" width="150" 
               click = "option_clickHandler(event)" />
            <s:RadioButton groupName = "options" id = "option3" 
               label = "item #3" width="150" 
               click = "option_clickHandler(event)" />
            <s:RadioButton groupName = "options" id = "option4" 
               label = "item #4" width = "150" 
               click = "option_clickHandler(event)" />
            <s:Label id = "selectedOptionLabel" fontWeight = "bold" 
               text = "Item selected: {selectedOption}" width = "150" />
         </s:Panel>
      </s:VGroup>	 
   </s:BorderContainer>	
</s:Application>

Once you are ready with all the changes done, let us compile and run the application in normal mode as we did in Flex - Create Application chapter. If everything is fine with your application, it will produce the following result: [ Try it online ]

flex_form_controls.htm