tabbarview不呈现任何内容

Question

我有这个小部件：

import 'package:buggerino_flutter/components/SelectPage.dart';
import 'package:buggerino_flutter/view_models/event_selected_view_model.dart';
import 'package:flutter/material.dart';

class EventSelectedPage extends StatefulWidget {
  final EventSelectedViewModel eventSelectedViewModel;

  EventSelectedPage({Key key, @required this.eventSelectedViewModel})
      : super(key: key) {
  }

  @override
  _EventSelectedPageState createState() => _EventSelectedPageState();
}

class _EventSelectedPageState extends State<EventSelectedPage>
    with SingleTickerProviderStateMixin {
  TabController _tabBarController;

  @override
  void initState() {
    super.initState();

    this._tabBarController = TabController(length: 4, vsync: this);
  }

  @override
  void dispose() {
    super.dispose();

    this._tabBarController.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return SelectPage(
      title: this.widget.eventSelectedViewModel.error.message,
      bottomNavigationBar: TabBar(
        controller: this._tabBarController,
        tabs: <Widget>[
          Tab(child: Text("Home"),),
          Tab(child: Text("Home"),),
          Tab(child: Text("Home"),),
          Tab(child: Text("Home"),)
        ],
      ),
      children: [
        SliverList(
          delegate: SliverChildListDelegate(
              [
                TabBarView(
                  controller: this._tabBarController,
                  children: <Widget>[
                    Text("foo"),
                    Text("foo"),
                    Text("foo"),
                    Text("foo"),
                  ],
                )
              ]
          ),
        )
      ],
    );
  }
}

它按预期方式呈现TabBar，但屏幕保持空白：

在请求下，失败了……我希望文本为“ foo”，但那里什么也没有。我想念什么吗？