| Package | mx.controls |
| Class | public class RadioButtonGroup |
| Inheritance | RadioButtonGroup  EventDispatcher Object |
| Implements | IMXMLObject |
| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 3 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
 | Starting with Flex 4.0, Adobe recommends that you use the spark.components.RadioButtonGroup class as an alternative to this class. |
The RadioButtonGroup control defines a group of RadioButton controls that act as a single mutually exclusive control; therefore, a user can select only one RadioButton control at a time. While grouping RadioButton instances in a RadioButtonGroup is optional, a group lets you do things like set a single event handler on a group of buttons, rather than on each individual button.
The id property is required when you use the
<mx:RadioButtonGroup> tag to define the name
of the group.
Notice that the RadioButtonGroup control is a subclass of EventDispatcher, not UIComponent, and implements the IMXMLObject interface. All other Flex visual components are subclasses of UIComponent, which implements the IUIComponent interface. The RadioButtonGroup control has support built into the Flex compiler that allows you to use the RadioButtonGroup control as a child of a Flex container, even though it does not implement IUIComponent. All other container children must implement the IUIComponent interface.
Therefore, if you try to define a visual component as a subclass of EventDispatcher that implements the IMXMLObject interface, you will not be able to use it as the child of a container.
MXML Syntax
Show MXML Syntax
Hide MXML SyntaxThe <mx:RadioButtonGroup> tag inherits all of the
tag attributes of its superclass, and adds the following tag attributes:
<mx:RadioButtonGroup
Properties
enabled="true|false"
id="No default"
labelPlacement="right|left|top|bottom"
Events
change="No default"
itemClick="No default"
/>
More examples
Learn more
Related API Elements
| Property | Defined By | ||
|---|---|---|---|
 | constructor : Object
A reference to the class object or constructor function for a given object instance. | Object | |
| enabled : Boolean
Determines whether selection is allowed. | RadioButtonGroup | ||
| labelPlacement : String
Position of the RadioButton label relative to the RadioButton icon
for each control in the group. | RadioButtonGroup | ||
| numRadioButtons : int [read-only]
The number of RadioButtons that belong to this RadioButtonGroup. | RadioButtonGroup | ||
| selectedValue : Object
The value of the value property of the selected
RadioButton control in the group, if this has been set
to be something other than null (the default value). | RadioButtonGroup | ||
| selection : RadioButton
Contains a reference to the currently selected
RadioButton control in the group. | RadioButtonGroup | ||
| Method | Defined By | ||
|---|---|---|---|
RadioButtonGroup(document:IFlexDisplayObject = null)
Constructor. | RadioButtonGroup | ||
| addEventListener(type:String, listener:Function, useCapture:Boolean = false, priority:int = 0, useWeakReference:Boolean = false):void
Registers an event listener object with an EventDispatcher object so that the listener
receives notification of an event. | EventDispatcher | |
|
Dispatches an event into the event flow. | EventDispatcher | |
Returns the RadioButton control at the specified index. | RadioButtonGroup | ||
|
Checks whether the EventDispatcher object has any listeners registered for a specific type
of event. | EventDispatcher | |
|
Indicates whether an object has a specified property defined. | Object | |
Implementation of the IMXMLObject.initialized() method
to support deferred instantiation. | RadioButtonGroup | ||
|
Indicates whether an instance of the Object class is in the prototype chain of the object specified
as the parameter. | Object | |
|
Indicates whether the specified property exists and is enumerable. | Object | |
|
Removes a listener from the EventDispatcher object. | EventDispatcher | |
|
Sets the availability of a dynamic property for loop operations. | Object | |
|
Returns the string representation of this object, formatted according to locale-specific conventions. | Object | |
|
Returns the string representation of the specified object. | Object | |
|
Returns the primitive value of the specified object. | Object | |
|
Checks whether an event listener is registered with this EventDispatcher object or any of
its ancestors for the specified event type. | EventDispatcher | |
| Event | Summary | Defined By | ||
|---|---|---|---|---|
| [broadcast event] Dispatched when the Flash Player or AIR application gains operating system focus and becomes active. | EventDispatcher | ||
| Dispatched when the value of the selected RadioButton control in this group changes. | RadioButtonGroup | |||
| [broadcast event] Dispatched when the Flash Player or AIR application operating loses system focus and is becoming inactive. | EventDispatcher | ||
| Dispatched when a user selects a RadioButton control in the group. | RadioButtonGroup | |||
enabled | property |
enabled:Boolean| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 3 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
Determines whether selection is allowed.
The default value is true.
This property can be used as the source for data binding. When this property is modified, it dispatches the enabledChanged event.
Implementation
public function get enabled():Boolean public function set enabled(value:Boolean):voidlabelPlacement | property |
labelPlacement:String| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 3 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
Position of the RadioButton label relative to the RadioButton icon for each control in the group. You can override this setting for the individual controls.
Valid values in MXML are "right", "left",
"bottom", and "top".
In ActionScript, you use the following constants to set this property:
ButtonLabelPlacement.RIGHT, ButtonLabelPlacement.LEFT,
ButtonLabelPlacement.BOTTOM, and ButtonLabelPlacement.TOP.
The default value is "right".
This property can be used as the source for data binding. When this property is modified, it dispatches the labelPlacementChanged event.
Implementation
public function get labelPlacement():String public function set labelPlacement(value:String):voidnumRadioButtons | property |
numRadioButtons:int [read-only] | Language Version: | ActionScript 3.0 |
| Product Version: | Flex 3 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
The number of RadioButtons that belong to this RadioButtonGroup.
The default value is "undefined".
This property can be used as the source for data binding. When this property is modified, it dispatches the numRadioButtonsChanged event.
Implementation
public function get numRadioButtons():intselectedValue | property |
selectedValue:Object| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 3 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
The value of the value property of the selected
RadioButton control in the group, if this has been set
to be something other than null (the default value).
Otherwise, selectedValue is the value of the
label property of the selected RadioButton.
If no RadioButton is selected, this property is null.
If you set selectedValue, Flex selects the
RadioButton control whose value or
label property matches this value.
The default value is null.
This property can be used as the source for data binding. When this property is modified, it dispatches the valueCommit event.
Implementation
public function get selectedValue():Object public function set selectedValue(value:Object):voidselection | property |
selection:RadioButton| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 3 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
Contains a reference to the currently selected
RadioButton control in the group.
You can access the property in ActionScript only;
it is not settable in MXML.
Setting this property to null deselects the currently selected RadioButton control.
The default value is null.
This property can be used as the source for data binding. When this property is modified, it dispatches the valueCommit event.
Implementation
public function get selection():RadioButton public function set selection(value:RadioButton):voidRadioButtonGroup | () | Constructor |
public function RadioButtonGroup(document:IFlexDisplayObject = null)| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 3 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
Constructor.
Parametersdocument:IFlexDisplayObject (default = null)document parameter should not be used.
|
Related API Elements
getRadioButtonAt | () | method |
public function getRadioButtonAt(index:int):RadioButton| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 3 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
Returns the RadioButton control at the specified index.
Parameters
index:int — The index of the RadioButton control in the
RadioButtonGroup control, where the index of the first control is 0.
|
RadioButton — The specified RadioButton control.
|
initialized | () | method |
public function initialized(document:Object, id:String):void| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 3 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
Implementation of the IMXMLObject.initialized() method
to support deferred instantiation.
Parameters
document:Object — The MXML document that created this object.
| |
id:String — The identifier used by document to refer to this object.
If the object is a deep property on document, id is null.
|
Related API Elements
change | Event |
flash.events.Eventproperty Event.type =
flash.events.Event.CHANGE| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 3 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
Dispatched when the value of the selected RadioButton control in this group changes.
TheEvent.CHANGE constant defines the value of the type property of a change event object.
This event has the following properties:
| Property | Value |
|---|---|
bubbles | true |
cancelable | false; there is no default behavior to cancel. |
currentTarget | The object that is actively processing the Event object with an event listener. |
target | The object that has had its value modified.
The target is not always the object in the display list
that registered the event listener. Use the currentTarget
property to access the object in the display list that is currently processing the event. |
itemClick | Event |
mx.events.ItemClickEventproperty ItemClickEvent.type =
mx.events.ItemClickEvent.ITEM_CLICK| Language Version: | ActionScript 3.0 |
| Product Version: | Flex 3 |
| Runtime Versions: | Flash Player 9, AIR 1.1 |
Dispatched when a user selects a RadioButton control in the group. You can also set a handler for individual RadioButton controls.
TheItemClickEvent.ITEM_CLICK constant defines the value of the
type property of the event object for an itemClick event.
The properties of the event object have the following values:
| Property | Value |
|---|---|
bubbles | false |
cancelable | false |
currentTarget | The Object that defines the
event listener that handles the event. For example, if you use
myButton.addEventListener() to register an event listener,
myButton is the value of the currentTarget. |
index | The index of the navigation item that was clicked. |
item | The item in the data provider of the navigation item that was clicked. |
label | The label of the navigation item that was clicked. |
relatedObject | The child object that generated the event. |
target | The Object that dispatched the event;
it is not always the Object listening for the event.
Use the currentTarget property to always access the
Object listening for the event. |
<?xml version="1.0" encoding="utf-8"?>
<!-- Simple example to demonstrate Halo RadioButtonGroup control. -->
<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">
<fx:Script>
<![CDATA[
import mx.controls.Alert;
import mx.events.ItemClickEvent;
// Event handler function to display the selected button
// in a Halo Alert control.
private function handleCard(evt:ItemClickEvent):void {
switch (evt.currentTarget.selectedValue) {
case "AmEx":
Alert.show("You selected American Express");
break;
case "MC":
Alert.show("You selected MasterCard");
break;
case "Visa":
Alert.show("You selected Visa");
break;
}
}
]]>
</fx:Script>
<fx:Declarations>
<mx:RadioButtonGroup id="cardtype" itemClick="handleCard(event);"/>
</fx:Declarations>
<s:Panel title="Halo RadioButtonGroup Control Example"
width="75%" height="75%"
horizontalCenter="0" verticalCenter="0">
<s:VGroup left="10" right="10" top="10" bottom="10">
<s:Label width="100%" color="blue"
text="Select a type of credit card."/>
<mx:RadioButton groupName="cardtype" id="americanExpress" value="AmEx"
label="American Express" width="150" />
<mx:RadioButton groupName="cardtype" id="masterCard" value="MC"
label="MasterCard" width="150" />
<mx:RadioButton groupName="cardtype" id="visa" value="Visa"
label="Visa" width="150" />
</s:VGroup>
</s:Panel>
</s:Application>
Thu Dec 6 2018, 01:12 PM -08:00