Question

我正在使用Java + Flex做一个项目。我创建了Java类并使用Flex远程对象来调用该方法。当我在mxml中编写所有代码时，它运行良好。但是当我将脚本包装在as文件中时，会有一些好奇的东西。我需要在Flex按钮上单击两次以获取远程对象返回的结果。我认为我的档案有问题。

以下是我的MXML：

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" 
           xmlns:s="library://ns.adobe.com/flex/spark" 
           xmlns:mx="library://ns.adobe.com/flex/mx"
           minWidth="500" minHeight="600">
<fx:Declarations>
    <mx:RemoteObject id="Control" destination="Control" showBusyCursor="true" />
</fx:Declarations>

<fx:Script>
    <![CDATA[
        import com.wntime.ControlUtil;
        import mx.rpc.events.ResultEvent;

        private var resultOfCmd:String;
        private var cmdStr:String;
        private var ct:ControlUtil = new ControlUtil();

        /* invoke as method */
        private function test():void
        {
            cmdStr = cmdTxt.text;
            resultOfCmd = ct.exec(cmdStr);
            cmdConsole.text = resultOfCmd;
        }

        /*  */
        private function exec():void{
            cmdStr = cmdTxt.text;
            Control.execCmd(cmdStr);
            Control.addEventListener(ResultEvent.RESULT,execCmd_clickHandler);
        }

        private function execCmd_clickHandler(event:ResultEvent):void
        {
            cmdConsole.text = event.result.toString();

        }

        private function clearCmdConsole():void
        {
            cmdConsole.text = "";
        }

    ]]>
</fx:Script>

<s:Panel id="CmdPanel" x="70" y="50" width="501" height="350" title="Command Execute Panel">
    <s:RichText x="20" y="33" fontSize="14" text="Cmd:"/>
    <s:TextInput id="cmdTxt" x="60" y="30" width="239"/>
    <s:Button id="execCmd" x="312" y="30" width="68" label="execute" click="exec()"/>
    <s:Button x="400" y="30" label="CmdTest" click="test()"/>
    <s:TextArea id="cmdConsole" x="20" y="85" width="450" editable="false"/>
    <s:Button x="400" y="250" label="clear" click="clearCmdConsole()"/>
</s:Panel>
</s:Application>

这是名为ControlUtil的as文件：

package com.wntime{
import mx.rpc.events.FaultEvent;
import mx.rpc.events.ResultEvent;
import mx.rpc.remoting.RemoteObject;

public class ControlUtil
{
    private var cmd:String = null;
    private var result:String = null;
    private var roControl:RemoteObject = new RemoteObject();

    public function ControlUtil()
    {
        roControl.destination = "Control";
    }

    public function exec(_cmd:String):String{
        this.cmd = _cmd;
        roControl.execCmd(cmd);
        roControl.addEventListener(FaultEvent.FAULT, execCmd); 
        roControl.addEventListener(ResultEvent.RESULT, execCmd);
        return result;
    }

    public function execCmd(event:ResultEvent):void
    {
        setResult(event.result.toString());
    }

    public function setResult(_result:String):void
    {
        this.result = _result;
    }

    }
}

如果单击执行按钮。结果将直接显示在控制台（textarea）中。但我需要在CmdTest按钮上单击两次以获得要在控制台中显示的结果。

请给我一个手。请提前谢谢。

Answer 1

这只是一个疯狂的猜测，但我认为您在Java端调用的方法返回的速度比添加侦听器的速度快，因此不会调用事件处理程序。所有听众第二次到位并且您的通话成功。尝试在调用远程方法之前添加侦听器。

Answer 2

我认为您的代码存在各种错误/问题，我会做类似的事情：

package com.wntime{
import mx.rpc.events.FaultEvent;
import mx.rpc.events.ResultEvent;
import mx.rpc.remoting.RemoteObject;

public class ControlUtil
{
    private var cmd:String = null;
    private var result:String = null;
    private var roControl:RemoteObject = new RemoteObject();
    // the callBack function is the function that is called when the 
    // remoteobject successfully or not complete the request... 
    // you can set as parameters anything you want...
    private var callBack:Function = null;
    public function ControlUtil()
    {
        roControl.destination = "Control";
    }

    public function exec(callBack:Function, _cmd:String):void{
        this.cmd = _cmd;
        this.callBack = callBack;
        roControl.addEventListener(FaultEvent.FAULT, errorCmd); 
        roControl.addEventListener(ResultEvent.RESULT, execCmd);
        roControl.execCmd(cmd);
    }

    private function execCmd(event:ResultEvent):void
    {           
        callBack(true,event.result.toString());
    }

    private function errorCmd(event:FaultEvent):void
    {
        callBack(false, event.error); // call the callBack function passing the value you need
    }  

}
}

callBack函数是这样的：

private function name(b:Boolean, s:String = null){....}

*编辑*

从主代码中调用exec命令...

// function invoked when the button is clicked!
private function buttonClick():void
{
    var tmp:ControlUtil = new ControlUtil();
    //exec(callBack:Function, _cmd:String)
    //you pass the function as a reference so when the async request is terminated the function is invoked and you can parse the result....
    tmp.exec(getResult, "cmqString");
}

// callBack function for the method ControlUtil.exec
private function getResult(b:Boolean, result:String = ""):void
{
    if (b)
    {
       // the call returned correctly and the result variable contains the value.
    }
    else
    {
       // the call failed and the result variable contains the error
    }
}

返回布尔值和结果值，因为我在使用callBack(true/false, result/error)

时在ControlUtil中指定了它

您可以根据需要创建该功能......

需要在Flex按钮上单击两次以获取RemoteObject结果

2 个答案: