http://livedocs.adobe.com/ Macromedia LiveDocs - online documentation with user feedback. Copyright 2009, Macromedia, Inc. 2009-11-26T11:15:11 en-us http://livedocs.adobe.com/flash/9.0/ActionScriptLangRefV3/flash/events/EventDispatcher.html#82504 Out of concern about the garbage collection of objects with event listeners, I ran a few experiments. I created a parent class with an enter frame event listener that instantiated a child each frame and displayed the memory usage of Flash, like so:<br /><br />Parent<br />{<br /> function enterFrame(event:Event):void<br /> {<br /> var c:Child = new Child();<br /> trace(System.totalMemory);<br /> }<br />}<br /><br />The child is not added to the display list and after enterFrame(), the parent has no references to it. By watching the memory usage, I determined that if the child...<br /><br />1. Has a keyboard or mouse event listener on itself citing a function either within the child class or outside, it is garbage collected.<br /><br />2. Has a reference to the parent [as in c = new Child(this)], it is garbage collected.<br /><br />3. Has a limited cycle timer with an event listener pointing to a function either within or outside the class, it is garbage collected.<br /><br />4. Has an enter frame event listener, it is _not_ garbage collected.<br /><br />5. Has an infinite cycle timer, it is _not_ garbage collected. Even if the child no longer maintains a reference to the timer.<br /><br />6. Has an event listener placed on an outside object (such as the parent) pointing to a function within the child class, it is _not_ garbage collected.<br /><br />The garbage collection scheme is thus quite intelligent. If you were to create a button object, for example, with only mouse and keyboard event listeners, there is no need to be concerned with memory issues caused by not removing event listeners.<br /><br />-Josh Josh Devan 0 0 2008-03-31T13:38:19