问上为啥FLEX的全屏时候TEXT INPUT控件不能接受键盘消息

问下为啥FLEX的全屏时候TEXT INPUT控件不能接受键盘消息
大家好，新年快乐！
所用的软件：FLEX BUILDER 3 + MyEclipse 6.0
我初学FLEX，碰到如下问题：
全屏代码如下：

        public function toggleFullScreen():void{
                    try {
                            var tim:Timer;
                        switch (Application.application.stage.displayState) {
                            case StageDisplayState.FULL_SCREEN:
                                Application.application.stage.displayState = StageDisplayState.NORMAL;
                              /*  tim = new Timer(1000,1);
                                            tim.addEventListener(TimerEvent.TIMER, function(event:TimerEvent):void {        
                                                    dispatchEvent(new Event(ResizeEvent.RESIZE));
                                            });*/
                                            
                                            //this.stage.displayState = StageDisplayState.NORMAL;
                            stage.scaleMode = StageScaleMode.NO_SCALE;
                             
                             //by SUNJUN
                                            MapController.gi().map.setZoom(MapController.gi().map.getZoom()-1);