flutter - 为什么在flutter中获取更多数据时GridView.builder会清除

Question

我有我的 GRidView 构建器，我有我的未来和我的 ScrollController，为什么当 scrollController 等于 mi maxScroll 时我的 gridView 会清除并获取更多信息？它应该显示所有内容，而不是最新信息。这是我的代码

future: _future ,
          builder: (BuildContext context, AsyncSnapshot snapshot) {   
            if(snapshot.hasData){            
              List<dynamic> loaded = snapshot.data;    
              return 
                Container(
                  width: double.infinity,
                  height: _screenSize.height * .8,
                  child:  GridView.builder(                        
                   gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
                     crossAxisCount: 3,
                     childAspectRatio:  MediaQuery.of(context).size.width /(MediaQuery.of(context).size.height /1.5),),
                    controller: _controller,     
                    itemCount: loaded.length,
                    itemBuilder: (context, i){
                      return _row(context,loaded,i); 
                    },                        
                  )
                );
            }else{

和构造函数

Future<List> _future;
ScrollController _controller = ScrollController(initialScrollOffset: 0.0, keepScrollOffset: true);
  _SearchPageState(){
  _controller.addListener(() {
  if(_controller.position.pixels >= _controller.position.maxScrollExtent-30 ){
    setState(() {
      _future = videoJuegos.getPaginationPopular();

    });
  }     
});    
_future = videoJuegos.getPaginationPopular();
}

标签： flutterdartfuture