屏蔽本层以下的层的touch消息

if(!this._listenerShield){
            var listener = cc.EventListener.create({
                event: cc.EventListener.TOUCH_ONE_BY_ONE,
                swallowTouches: true,
                onTouchBegan: function (touch, event) {
                    return true;
                }
            });
            cc.eventManager.addListener(listener, this);
            this._listener = listener;


        }

if(this._listener){
            cc.eventManager.removeListener(this._listener);
            this._listenerShield = null;


        }