帮忙注释一下代码解决方案

帮忙注释一下代码
package{
import flash.events.*;
public class Thermometer extends EventDispatcher{
private var _temp:Number=32;
public static const TEMP_CHANGED:String="tempChanged";
public function set temp(newTemp:Number):void{
_temp=newTemp;
trace("Fired TEMP_CHANGED event");
dispatchEvent(new Event(TEMP_CHANGED));
}
public function get temp():Number{
return _temp;
}
}
}

package{
import Thermometer;
import flash.events.*;
public class TempDisplay{
public function TempDisplay(thermometer:Thermometer){
thermometer.addEventListener(Thermometer.TEMP_CHANGED,onTempChanged);
}
protected function onTempChanged(event:Event):void{
var thermometer:Thermometer=Thermometer(event.target);
trace(thermometer.temp+"F");
}
}
}

package{
import flash.display.*;
public class TemperatureMonitor extends Sprite{
protected var thermometer:Thermometer;
protected var tempDisplayF:TempDisplay;
public function TemperatureMonitor(){
thermometer=new Thermometer();
tempDisplayF=new TempDisplay(thermometer);
thermometer.temp=57;
thermometer.temp=98.6;
thermometer.temp=-12;
}
}
}

[解决办法]

Java code

package{import flash.events.*;public class Thermometer extends EventDispatcher{private var _temp:Number=32;//温度public static const TEMP_CHANGED:String="tempChanged";//温度改变事件//设置温度public function set temp(newTemp:Number):void{_temp=newTemp;trace("Fired TEMP_CHANGED event");dispatchEvent(new Event(TEMP_CHANGED));//派发温度改变事件}//获取温度public function get temp():Number{return _temp;}}}package{import Thermometer;import flash.events.*;public class TempDisplay{public function TempDisplay(thermometer:Thermometer){    //监听温度改变事件thermometer.addEventListener(Thermometer.TEMP_CHANGED,onTempChanged);}//温度改变后进行处理protected function onTempChanged(event:Event):void{var thermometer:Thermometer=Thermometer(event.target);trace(thermometer.temp+"F");}}}package{import flash.display.*;public class TemperatureMonitor extends Sprite{protected var thermometer:Thermometer;protected var tempDisplayF:TempDisplay;public function TemperatureMonitor(){thermometer=new Thermometer();tempDisplayF=new TempDisplay(thermometer);thermometer.temp=57;thermometer.temp=98.6;thermometer.temp=-12;}}}
[解决办法]
thermometer这是一个对象，event.target当前操作对象