Array应用，对象应用

private var desction:Array = [0,0,0,0];
        private function onKeyDownHandler(_evt:KeyboardEvent):void {
            switch (_evt.keyCode) {
                case 37:
                    desction[0] = 1;
                    break;
                case 38:
                    desction[1] = 1;
                    break;
                case 39:
                    desction[2] = 1;
                    break;
                case 40:
                    desction[3] = 1;
                    break;
                default:
                    break;
            }
            //txt.text = desction.toString();
            trace("值：" + desction.toString())
            downTest(desction.join(""));
        }
        private function downTest(k:String):void {
            switch (k) {
                    case "0110":
                        txt.text = "  上+右";
                        break;
                    case "1100":
                        txt.text = "  上+左";
                        break;
                    case "0011":
                        txt.text = "  下+右";
                        break;
                    case "1001":
                        txt.text = "  下+左";
                        break;
                    case "1010":
                        txt.text = "  左+右";
                        break;
                    case "0101":
                        txt.text = "  上+下";
                        break;
                    case "1000":
                        txt.text = "  左";
                        break;
                    case "0100":
                        txt.text = "  上";
                        break;
                    case "0010":
                        txt.text = "  右";
                        break;
                    case "0001":
                        txt.text = "  下";
                        break;
                    default:
                        break;
                }
        }
        private function onKeyUpHandler(_evt:KeyboardEvent):void {
            switch (_evt.keyCode) {
                case 37:
                    desction[0] = 0;
                    break;
                case 38:
                    desction[1] = 0;
                    break;
                case 39:
                    desction[2] = 0;
                    break;
                case 40:
                    desction[3] = 0;
                    break;
                default:
                    break;
            }
        }

 对象应用:

var key_obj:Object = new Object();

private function onKeyDownHandler1(_evt:KeyboardEvent):void {
            var _code:String = String.fromCharCode(_evt.charCode);
            key_obj[_code] = true;
            
            for (var p:String in key_obj){ //用于其它字母和数字鍵
                trace("当前按下的键有：" + p + "值=true(key_obj[p])");
            }
            /*_evt.ctrlKey && trace("Ctrl键被按下");
               _evt.altKey && trace("Alt键被按下");
             _evt.shiftKey && trace("Shift键被按下");*/
        }

        private function onKeyUpHandler1(_evt:KeyboardEvent):void {
            var _code:String = String.fromCharCode(_evt.charCode);
            
            key_obj[_code] = null;
            delete key_obj[_code];
        }