package {
    import flash.display.Sprite;
    import fl.controls.Label;
    import flash.events.KeyboardEvent;
    import flash.ui.Keyboard;
    import flash.ui.*;
 
    public class KeyDown extends Sprite {
 
        private var lbl:Label;
        private var ball:Sprite;
        private var keyValueArr:Array;//捕获组合键时，用来存放本次（在未触KeyUp事件前）所有按下的所有键值
        private var keyNameArr:Array;//按键值对应的字符
 
        public function KeyDown():void {
            init();
        }
 
        private function init():void {
            stage.focus=this;//N多资料上说要先设置焦点，但是在实际测试中，发现不加这一行，好象也能处理键盘事件?
 
            lbl = new Label();
            lbl.text="请按键(支持Ctrl,Shift组合键)，这里将显示您的按键值，按方向键可以移动小球(支持8方向)";
            lbl.autoSize="center";
            addChild(lbl);
            lbl.width=stage.stageWidth;
            lbl.height=20;
            lbl.move(0,10);
 
            ball = new Sprite();
            addChild(ball);
 
            //画小球 
            ball.graphics.beginFill(0xff0000);
            ball.graphics.drawCircle(0,0,30);
            ball.graphics.endFill();
 
            //定位到舞台中心
            ball.x=stage.stageWidth/2;
            ball.y=stage.stageHeight/2;
 
            stage.addEventListener(KeyboardEvent.KEY_DOWN,KeyDownHandler);
            stage.addEventListener(KeyboardEvent.KEY_UP,KeyUpHandler);
 
            keyValueArr = new Array();
            keyNameArr = new Array();
        }
 
        public function KeyDownHandler(e:KeyboardEvent):void {
            //注:既然Alt总是被浏览器或播放器菜单栏 拦截，干脆就不检测了
            if (!(e.keyCode==Keyboard.SHIFT||e.keyCode==Keyboard.CONTROL)) {
                if (keyValueArr.indexOf(e.keyCode)==-1) {
                    keyValueArr.push(e.keyCode);
                    keyNameArr.push(String.fromCharCode(e.keyCode));
                }
            }
 
            lbl.text="您的按键值是："+ keyValueArr.join('，') +"；按键是：" + keyNameArr.join('，');
 
            //单方向移动
            if (keyValueArr.length==1) {
                switch (e.keyCode) {
                    case Keyboard.UP :
                        ball.y-=10;
                        break;
                    case Keyboard.DOWN :
                        ball.y+=10;
                        break;
                    case Keyboard.LEFT :
                        ball.x-=10;
                        break;
                    case Keyboard.RIGHT :
                        ball.x+=10;
                    default :
                        break;
                }
            } else if (keyValueArr.length>1) {
                //trace(keyValueArr.join('，'));             
                if (keyValueArr.indexOf(Keyboard.UP)!=-1 && keyValueArr.indexOf(Keyboard.LEFT)!=-1) {       
                    //左上
                    ball.x -= 10;
                    ball.y -= 10;
                } else if (keyValueArr.indexOf(Keyboard.UP)!=-1 && keyValueArr.indexOf(Keyboard.RIGHT)!=-1) {
                    //右上
                    ball.x += 10;
                    ball.y -= 10;
                }
                else if (keyValueArr.indexOf(Keyboard.DOWN)!=-1 && keyValueArr.indexOf(Keyboard.RIGHT)!=-1) {
                    //右下
                    ball.x += 10;
                    ball.y += 10;
                }
                else if (keyValueArr.indexOf(Keyboard.DOWN)!=-1 && keyValueArr.indexOf(Keyboard.LEFT)!=-1) {
                    //左下
                    ball.x -= 10;
                    ball.y += 10;
                }
            }
 
            if (e.ctrlKey) {
                if (keyValueArr.length>0) {
                    lbl.text="您按下了Ctrl + "+keyNameArr.join(',');
                }
            }
            if (e.shiftKey) {
                if (keyValueArr.length>0) {
                    lbl.text="您按下了Shift + "+keyNameArr.join(',');
                }
            }
 
        }
 
        public function KeyUpHandler(e:KeyboardEvent):void {
            keyValueArr.length=0;
            keyNameArr.length=0;
        }
    }
}