如何在ActionScript 3中编写key_down处理程序？

Question

好的，我尝试了大约8种不同的方法来将关键事件纳入我的代码中，但它们似乎都没有用。有人可以告诉我，当我按轮班时我如何移动这个球？先感谢您

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" 
  styleName = "plain"
    xmlns="cyanprime.*" 
    layout="absolute"
    width="600"
    height="400"
    frameRate="100"
    creationComplete="initApp()">

    <mx:Script>
        <![CDATA[
            public function initApp():void
            {

                Mouse.hide();
                canvas.init();
                canvas.addEventListener(KeyboardEvent.KEY_DOWN, keyDown);
            }

            private function keyDown(event:KeyboardEvent):void
            {
                canvas.KeyDownHandler(event);
            }
        ]]>
    </mx:Script>

  <MyGameCanvas id="canvas" width="100%" height="100%" themeColor="#ff000000" />
</mx:Application>

...

package cyanprime{

    import mx.core.UIComponent;
    import mx.controls.Image;
    import flash.events.*;
    import flash.utils.*;
    import flash.display.*;
    import flash.ui.Keyboard;

    public class MyGameCanvas extends UIComponent{
        [Embed(source="player.gif")]
        private var playerImage:Class;

        private var player:DisplayObject = new playerImage();
        private var player_x:Number;
        private var player_y:Number;
        private var ticker:Timer;



        public function init():void{
            // set up player
            addChild(player);

            ticker = new Timer(10); 
            ticker.addEventListener(TimerEvent.TIMER, onTick);
            ticker.start();

        }

        public function KeyDownHandler(event:KeyboardEvent):void{
            if(event.keyCode == Keyboard.SHIFT)
            player_x += 50;
        }

        public function onTick(evt:TimerEvent):void {
        }       
    }
}

Answer 1

您需要将侦听器添加到舞台上，并在发生ApplicationComplete事件（或在其处理程序中）之后进行广告

<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" applicationComplete="init()">
 <mx:Script>
    <![CDATA[

    public function init():void
    {
        trace('Initialization');
        stage.addEventListener(KeyboardEvent.KEY_DOWN, keyDown);    
    }

    private function keyDown(event:KeyboardEvent):void
    {
        trace(event.charCode);
    }       
    ]]>
 </mx:Script>
</mx:Application>

参考