Conditional handler : Event Handler « Event « Flex

1. Flex
2. Event
3. Event Handler

Conditional handler

            


<!--
Code from Flex 4 Documentation "Using Adobe Flex 4".

This user guide is licensed for use under the terms of the Creative Commons Attribution 
Non-Commercial 3.0 License. 

This License allows users to copy, distribute, and transmit the user guide for noncommercial 
purposes only so long as 
  (1) proper attribution to Adobe is given as the owner of the user guide; and 
  (2) any reuse or distribution of the user guide contains a notice that use of the user guide is governed by these terms. 
The best way to provide notice is to include the following link. 
To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/

-->



<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
    xmlns:mx="library://ns.adobe.com/flex/mx"
    xmlns:s="library://ns.adobe.com/flex/spark"
    initialize="initApp(event)">
    <s:layout>
        <s:VerticalLayout />
    </s:layout>
    <fx:Script>
         
        import mx.controls.Alert; 
        private function initApp(e:Event):void { 
            cb1.addEventListener(MouseEvent.CLICK, handleCheckBoxChange); 
            b1.addEventListener(MouseEvent.CLICK, logAction); 
        } 
        private function handleCheckBoxChange(e:Event):void { 
            if (cb1.selected) { 
                b1.addEventListener(MouseEvent.CLICK, logAction); 
                ta1.text += "Added log listener." + "\n"; 
            } else { 
                b1.removeEventListener(MouseEvent.CLICK, logAction); 
                ta1.text += "Removed log listener." + "\n"; 
            } 
        } 
        private function performAction(e:Event):void { 
            Alert.show("You performed the action."); 
        } 
        private function logAction(e:Event):void { 
            ta1.text += "Action performed: " + e.type + ".\n"; 
        } 
      
    </fx:Script>
    <s:Button label="Perform Action" id="b1"
        click="performAction(event)" />
    <s:CheckBox id="cb1" label="Log?" selected="true" />
    <s:TextArea id="ta1" height="200" width="300" />
</s:Application>

   
    
    
    
    
    
    
    
    
    
    
    
  

Related examples in the same category

1.	Using event object to make event handlers more generic
2.	Creating function and use it as event handler
3.	A function returning String and use it in button event handler
4.	Register handler function to Button control
5.	Remove handler
6.	Use the handler property to specify the function Argument String
7.	Use the handlerFunction property to specify the function
8.	Add handlers and then remove handlers
9.	Using ActionScript in MXML event handlers
10.	Specify Event object as a parameter in the event handler function
11.	Define an event handler inline and binds a call to the handler function to the control
12.	Event handler function
13.	Parent container's click handler disables the target control after the target handles the event
14.	Handler children clicked event from parent clicked event
15.	Priority parameter and event handler event
16.	Add itself to event handler
17.	To use the Event object, you specify it as a parameter in the event handler function
18.	Create two event handler functions
19.	Bind a call to the handler function to the control that triggers the event
20.	Simple Event Handler
21.	Pass string into event handler
22.	Use initialize event to register event handler
23.	Event handler sequence
24.	Use SetEventHandler to set event handler to a target
25.	Add SecurityErrorEvent.SECURITY_ERROR event handler
26.	Write simple event handler code inline
27.	Add event handler to ChangeWatcher
28.	Use itemDoubleClick event handler to display HitData information
29.	Event Object Handler
30.	Define variable in click event handler
31.	Handler result event and fault event for ItemResponder
32.	Using removeEventListener() method to remove event handler
33.	Add and remove event handlers
34.	Gets the value of the current target's x, y, and width properties in the focusIn event handler,
35.	Define an event handler for the drag
36.	Creates the groups in ActionScript by using an event handler