var fullscreenMode:Boolean = false; fs_btn.addEventListener(MouseEvent.CLICK,onbtnHandle); function onbtnHandle(evt:MouseEvent):void { if (fullscreenMode==false) { fullscreenMode=true; stage.displayState=StageDisplayState.FULL_SCREEN; } else if (fullscreenMode == true) { fullscreenMode=false; stage.displayState=StageDisplayState.NORMAL; } } 舞台上按钮名字是fs_btn