首先需要修改index.template.html生成的静态模板页面,使用js监听document.onmousedown事件，并调用Flex里暴露的方法，代码如下：(Index为生成的flash对象id)

function onNsRightClick(e){
     if(e.which == 3){
          Index.openRightClick();
          e.stopPropagation(); 
     }
     return false;
}

function onIeRightClick(e){
     if(event.button > 1){
          Index.openRightClick();
          parent.frames.location.replace('javascript: parent.falseframe');
     }
     return false;
}


if(navigator.appName == "Netscape"){
     document.captureEvents(Event.MOUSEDOWN); 
     document.addEventListener("mousedown", onNsRightClick, true); 
}
else{
     document.onmousedown=onIeRightClick; 
}

第二步，还需要修改index.template.html默认生成flash的脚本，在AC_FL_RunContent方法调用里添加一行"wmode", "opaque",参数设置，这是关键。

最后，在Flex端注册暴露能被js调用的函数，ExternalInterface.addCallback("openRightClick", openRightClick);我的是写在Application的creationComplete事件里的，另外增加Application的mouseOver、mouseDown事件，在showMouseEvent方法里就能自定义模拟显示右键菜单了，mxml代码如下：

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" 
    verticalGap="0" scroll="false"
    horizontalScrollPolicy="off" verticalScrollPolicy="off"
    creationComplete="init()" initialize="initApp(event)"
    mouseOver="getMouseTarget(event)" mouseDown="showMouseEvent(event)" >
    <mx:Style source="/styles/index/css/style.css"></mx:Style>
    <mx:HTTPService id="httpsLogin" url="/Flex/Login.aspx" method="get" showBusyCursor="true" result="httpsLogin_Result()" >
        <mx:request xmlns="">
            <username>
                {this.txtUserName.text}
            </username>
            <password>
                {this.txtPassword.text}
            </password>
        </mx:request>
    </mx:HTTPService>
    <mx:Script>
        <![CDATA[
            import mx.managers.ICursorManager;
            import mx.managers.CursorManagerPriority;
        
            import mx.controls.Alert;
            import mx.managers.CursorManager;
            
            import org.bytearray.gif.player.GIFPlayer;   
            import org.bytearray.gif.events.FileTypeEvent;   
            import org.bytearray.gif.events.GIFPlayerEvent;   
            import org.bytearray.gif.events.FrameEvent;   
            import org.bytearray.gif.events.TimeoutEvent;
            
            [Embed(source="/styles/index/images/cursor.gif")] 
            private var cursorHand : Class;//图标
            
            private var mouseTarget:DisplayObject;
            
            //public var myGIFPlayer:GIFPlayer = new GIFPlayer();

            public function httpsLogin_Result() : void
            {
                var rs : String  = httpsLogin.lastResult.result;
                if ( rs=="true")
                {
                    mx.controls.Alert.show("登陆成功！","提示信息", Alert.OK, this,null,null, Alert.YES);
                    return;
                }
                mx.controls.Alert.show(rs,"提示信息",Alert.OK,this,null,null, Alert.OK);
                
            }
            
            public function init():void
            {
                var date:Date = new Date();
                swfHeader.source += "&daytime=" + (date.getHours() >= 18 ? "no" : "yes");
                
                ExternalInterface.addCallback("openRightClick", openRightClick);

            }
            
            
            private function getMouseTarget(event:MouseEvent):void
            {
               mouseTarget = DisplayObject(event.target);
            }
            
            private function openRightClick():void
            {
                 var e:MouseEvent = new MouseEvent(MouseEvent.MOUSE_DOWN, true, false, mouseTarget.mouseX, mouseTarget.mouseY);
                 mouseTarget.dispatchEvent(e);
            }
            
            private function showMouseEvent(event:MouseEvent):void
            {
                 if(event.buttonDown == true)
                  Alert.show("Left");
                 else
                  Alert.show("Right");
            }
            
        ]]>
    </mx:Script>
    <mx:SWFLoader id="swfHeader" width="700" height="255" source="/style/blog/mobile.swf?menu=true&amp;currentState=sunny&amp;tempVar=11">
    </mx:SWFLoader>
    <mx:HBox styleName="nav" width="960" height="58" horizontalGap="50" paddingTop="25">
        <mx:LinkButton left="10" click="ExternalInterface.call('function(){location.reload();}')" label="首页"/>
        <mx:LinkButton label="随笔"/>
        <mx:LinkButton label="相册"/>
        <mx:LinkButton label="留言"/>
    </mx:HBox>
    <mx:VBox width="960" visible="false">
        <mx:Panel width="364" height="234" backgroundAlpha="2" layout="absolute" fontSize="12" title="个人档案">
            <mx:Label x="47" y="37" text="用户名："/>
            <mx:TextInput x="110" y="37" id="txtUserName"/>
            <mx:Label x="47" y="89" text="密　码："/>
            <mx:TextInput x="110" y="89" id="txtPassword"/>
            <mx:Button x="110" y="141" click="httpsLogin.send()" label="登陆"/>
        </mx:Panel>
        <mx:Panel width="364" height="234" layout="absolute" fontSize="12" title="日历">
            <mx:Label x="47" y="37" text="用户名："/>
            <mx:Button x="110" y="141" click="httpsLogin.send()" label="登陆"/>
        </mx:Panel>    
    </mx:VBox>
    
</mx:Application>

凡事有利就有弊，由于屏蔽了右键菜单，TextInput文本框默认也没有粘贴的选项了，由于设置了flash的wmode为opaque，导致一些中文输入的反作用，所以没有特别的需求还是不屏蔽到默认右键菜单，如果要加上一些自己定义的上下文菜单，Flex内也很简单，在Application的上下文内添加条不可选的菜单项实现如下：

// 隐藏一些内建的鼠标右键菜单项
this.contextMenu.hideBuiltInItems(); 
var contextMenuItem : ContextMenuItem = new ContextMenuItem("Powered By: Jonllen");
contextMenuItem.enabled = false;
contextMenu.customItems.push(contextMenuItem);
this.contextMenu.customItems.push(contextMenuItem);