Flex actionscript，从 AsyncToken 调用中获取数据

Question

我有 blazeDS 的 Flex/Java 项目。现在我有一个 actionscript 文件，它调用另一个 actionscript 的方法，该方法调用 remoteObject（在 db 上进行简单选择的 java 类）

代码如下：

Home.as

..
private var _dm:DataManager = new DataManager;
public function getPerson():void { // this is connect to a button in .mxml
    _dm.getPerson();
}
..

DataManager.as

public class DataManager {
    private var _service:RemoteObject;
    private var _url:URLRequest;
    private var loCs:ChannelSet = new ChannelSet();

    public function DataManager () {
        _service = new RemoteObject("PeopleDAO");
        loCs.addChannel(new AMFChannel("canale", "http://localhost:8080/FlexTRYOUT/messagebroker/amf"));
        _service.channelSet = loCs;
    }

    private function onFault(event:FaultEvent,token:Object):void {
        var _fail:String = "fault";
    }
    private function onResult(event:ResultEvent,token:Object):void {
        per = event.result as People; // is a bean class
        Alert.show(per.nome);
    }

    public function getPerson():void {
        var token:AsyncToken = _service.getPersona();
        token.addResponder(new AsyncResponder(onResult,onFault));
    }
}

调用工作正常，它调用DataManger.java 类的java 方法名称getPerson()。它只返回一个带有姓名和姓氏的对象（理解这个该死的 AsyncCall 只是一个很好的世界）。问题是我不知道如何使用经典（java）返回类型将此结果发送到Home.as。我在onResult 方法中有结果，但我不知道如何得到它。

我尝试按照 Brian 的指示进行操作，但我只是在浪费时间。也许是因为我不是 flex actionscript 程序员，但我添加了 Brian 发布的代码：

public function getPerson():void { // this is connect to a button in .mxml
    _dm.addEventListener(DATA_RECEIVED, onPersonFound); * compile error 1
    _dm.getPerson();
}

错误是 DATA_RECEIVED 未定义

比在 DataManager 中：

public class DataManager {
    public static const DATA_RECEIVED:String = "DATA_RECEIVED";

    ...

    private function onResult(event:ResultEvent,token:Object):void {
        per = event.result as People; // is a bean class
        dispatchEvent(new DataReceivedEvent(DATA_RECEIVED, per)); * compile error 2
    }
}

错误 2 是调用了可能的未定义方法 dispatchEvent

错在哪里？请大家写下完整的代码，因为我在使用 flex - actionscript - 从两天开始就开始了，我有一些时间来尝试解决方案。谢谢

好的，对不起，我只是用同样的问题创建一个新的（但更详细和更清晰）。一步一步我正在研究这种语言，并且我设法实现了 Brian 代码，但是 DataManager.as 类必须扩展 EventDispatcher，如果我不扩展它，我就会发布我发布的编译错误。目前我设法在 addEventListener 调用中定义的方法中获取 resultEvent 数据（在本例中为 onPeopleFound ）。非常感谢布赖恩，我想我将来肯定会再次需要你的帮助（至少在项目被接受之前）。再见

Answer 1

您可以调整方法getPerson 使两个参数引用回调函数。

public function getPerson(onResultCallback:Function, onFaultCallback:Function):void {
   var token:AsyncToken = _service.getPersona();
   token.addResponder(new AsyncResponder(onResultCallback,onFaultCallback));
}

这样你可以在你需要的类的实例中接收数据。

Answer 2

一种选择是在您从 Java 调用中取回数据时分派一个事件：

Home.as

...
public function getPerson():void { // this is connect to a button in .mxml
    _dm.addEventListener(DATA_RECEIVED, onPersonFound);
    _dm.getPerson();
}

private function onPersonFound(dataEvent:DataReceivedEvent):void {
    var person:People = dataEvent.people;
    //Do important processing...
}
...

在 DataManager.as 中

public class DataManager {
    public static const DATA_RECEIVED:String = "DATA_RECEIVED";

    ...

    private function onResult(event:ResultEvent,token:Object):void {
        per = event.result as People; // is a bean class
        dispatchEvent(new DataReceivedEvent(DATA_RECEIVED, per));
    }
}

DataReceivedEvent.as 看起来就像How to dispatch an event with added data - AS3 的答案

public class DataReceivedEvent extends Event
{
    public static const DATA_RECEIVED:String = "DATA_RECEIVED";

    // this is the object you want to pass through your event.
    public var result:Object;

    public function DataReceivedEvent(type:String, result:Object, bubbles:Boolean=false, cancelable:Boolean=false)
    {
        super(type, bubbles, cancelable);
        this.result = result;
    }

    // always create a clone() method for events in case you want to redispatch them.
    public override function clone():Event
    {
        return new DataReceivedEvent(type, result, bubbles, cancelable);
    }
}