android - 错误 SmartWall airpush，void 是变量 onAdCached 的无效类型

Question

我有这个代码：

info.setOnClickListener(new OnClickListener(){
        @Override
        public void onClick(View arg0) {
            // TODO Auto-generated method stub
            if(ma==null)
                ma = new MA(my, adCallbackListener, true);   // ad caching is enabled

            ma.callAppWall();   //this will start the AppWall ad but it will not show you AppWall instantly.  
            @Override
            public void onAdCached(AdType adType) {


                //you will receive the information here if an ad is cached. 

            }

            ma.showCachedAd(my, AdType.appwall);


}});

onAdCached 方法给了我以下错误：

“void 是变量 onAdCached 的无效类型” 为什么？我希望解决。