User Guide

686 ActionScript classes

Example

The following example shows how to use the

length property to ascertain the number of

listener objects currently registered to the Key object.

var myListener:Object = new Object();

myListener.onKeyDown = function () {

trace ("You pressed a key.");

}

Key.addListener(myListener);

trace(Key._listeners.length); // Output: 1

onKeyDown (Key.onKeyDown event listener)

onKeyDown = function() {}

Notified when a key is pressed. To use onKeyDown, you must create a listener object. You can

then define a function for

onKeyDown and use addListener() to register the listener with the

Key object, as shown in the following example:

var keyListener:Object = new Object();

keyListener.onKeyDown = function() {

trace("DOWN -> Code: "+Key.getCode()+"\tACSII: "+Key.getAscii()+"\tKey:

"+chr(Key.getAscii()));

};

keyListener.onKeyUp = function() {

trace("UP -> Code: "+Key.getCode()+"\tACSII: "+Key.getAscii()+"\tKey:

"+chr(Key.getAscii()));

};

Key.addListener(keyListener);

Listeners enable different pieces of code to cooperate because multiple listeners can receive

notification about a single event.

A Flash application can only monitor keyboard events that occur within its focus. A Flash

application cannot detect keyboard events in another application.

Availability: ActionScript 1.0; Flash Player 6