Macromedia flex 2-migrating applications to flex 2 Manual De Usuario

Using function listeners

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To find the appropriate static constant for your event type, see the events section of the 
control’s entry in Adobe Flex 2 Language Reference.

Using function listeners

When migrating, convert all object event listeners to function event listeners. You can no 
longer pass an object as the second parameter to the 

addEventListener()

 method. The 

listener argument of the 

addEventListener()

 method was of type Object, which also 

accepted a Function, but is now of type Function. If you try to pass an object listener, Flex 
reports an error.

For example, if you had the following:

<?xml version="1.0"?>
<mx:Application xmlns:mx="http://www.macromedia.com/2003/mxml" 

creationComplete="createHandler()">

<mx:Script>
import mx.core.Alert;
function createHandler() {

var myListener = new Object();
myListener.click = function(event) {

Alert.show("This is a log message");

}
myButton.addEventListener("click", myListener);
trace("Added listener");

}
</mx:Script>
<mx:Button label="Click Me" id="myButton"/>

</mx:Application>

Convert it to the following:

<?xml version="1.0"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" 

creationComplete="createHandler()">

<mx:Script>
import mx.controls.Alert;
private function createHandler():void {

trace("Added listener");
button1.addEventListener(MouseEvent.CLICK, myClickHandler);

}
private function myClickHandler(event:MouseEvent):void {

Alert.show("This is a log message");

} 
</mx:Script>
<mx:Button label="Click Me" id="button1"/>

</mx:Application>