Flutter -在使用StreamBuilder从firebase获取数据后，如何使用ScrollController跳转到列表视图的底部？

ScrollController _scrollController;

@override
void initState() {
  super.initState();
  _scrollController = ScrollController();
}

StreamBuilder(
  stream: yourStream, // 从Firebase获取的数据流
  builder: (BuildContext context, AsyncSnapshot snapshot) {
    if (snapshot.hasData) {
      WidgetsBinding.instance.addPostFrameCallback((_) {
        _scrollController.animateTo(
          _scrollController.position.maxScrollExtent,
          duration: Duration(milliseconds: 300),
          curve: Curves.easeOut,
        );
      });
      return ListView.builder(
        controller: _scrollController,
        itemCount: snapshot.data.length,
        itemBuilder: (BuildContext context, int index) {
          // 构建列表项
        },
      );
    } else {
      return CircularProgressIndicator();
    }
  },
)