How to extend ObjectProxy class

I trying to extends ObjectProxy class, the reason is because I want to have a Singleton of the ObjectProxy class, so I made something like

package utils
{
    import mx.utils.开发者_StackOverflow社区ObjectProxy;

    public class UniformObjectProxy extends ObjectProxy
    {
        private static var _instance:UniformObjectProxy;

        public function UniformObjectProxy(secure:PrivateClass, item:Object=null, uid:String=null, proxyDepth:int=-1)
        {
            super(item, uid, proxyDepth);
        }

        public static function getInstance(item:Object=null):UniformObjectProxy{
            if(UniformObjectProxy._instance == null){
                var security:PrivateClass = new PrivateClass();
                UniformObjectProxy._instance = new UniformObjectProxy(security, item);
            }
            return UniformObjectProxy._instance;
        }
    }
}

class PrivateClass{
    public function PrivateClass(){

    }
}

when I create my object uniform which is a simple object, I pass it to my UniformObjectProxy.getInstance() static method to get the instance of my objectProxy, ok so far so good

my problem is when I try to bind a property of my objectProxy instance like

_opc = UniformObjectProxy.getInstance(_uniform);
cw:ChangeWatcher = BindingUtils.bindSetter(dispatchColorChange, _opc, data.id);

the dispatchColorChange handler function is called only once an never again, I had check ChangeWatcher.isWatching() and return false meaning my objectProxy is not binding properly, if I create an objectProxy like

_opc = new ObjectProxy(_uniform);
cw:ChangeWatcher = BindingUtils.bindSetter(dispatchColorChange, _opc, data.id);

the binds works just fine, so my thinking is the problem is when I extends the objectProxy class, how is the proper way to do this, please help me!, thanks for any clue!!

There seems to be problems extending ObjectProxy (personally I encountered namespace issues while trying overriding the setProperty method and have the feeling this class is just not meant to be used the same way as the Proxy class).

Not a direct answer to your question but I guess you shouldn't have to stick to the singleton pattern just for the sake of it. To get the same access/result described above I would suggest doing something like this :

package utils
{
    import mx.utils.ObjectProxy;

    public class UniformObjectProxy
    {
        private static var _proxy:ObjectProxy;

        public function UniformObjectProxy()
        {
            throw("do not instantiate me!")
        }

        public static function getProxy(item:Object=null):ObjectProxy{
            if(_proxy == null){
                _proxy = new ObjectProxy(item);
            }
            return _proxy;
        }
    }
}

and then :

var _opc:ObjectProxy = UniformObjectProxy.getProxy(_uniform);