FutureBuilder仅用于调试

Question

我有一个带有ListView的FutureBuilder来显示自定义项（小部件），其值是从。txt文件中读取的。

问题是，只有当我在调试模式或运行模式下启动应用程序时，这些项才会显示。当我试图用AppLauncher打开应用程序时（就像“普通”用户会这样做一样），listView是空的。我在一个AVD和一个“真正的”设备上试过这个。

class Home extends StatefulWidget {
  final Future listFuture = setupList();

  @protected
  @mustCallSuper
  void initState() {
    print("init complete");
  }

  @override
  State<StatefulWidget> createState() {
    return HomeState();
  }
}

child: FutureBuilder<List<SubListItem>>(
                      future: widget.listFuture,
                      // ignore: missing_return
                      builder: (BuildContext context, AsyncSnapshot snapshot) {
                        switch (snapshot.connectionState) {
                          case ConnectionState.none:
                            return new Text("None");
                          case ConnectionState.waiting:
                            return new Text("loading");
                          default:
                            if (snapshot.hasError) {
                              print("Error");
                              return Center(child: (Text("No data")));
                            } else {
                              return subListView(context, snapshot);
                            }
                        }
                      },
                    ),

Widget subListView(BuildContext context, AsyncSnapshot snapshot) {
  List<Widget> items = snapshot.data;

  //This ScrollConfiguration is used to remove any animations while scrolling
  return ScrollConfiguration(
    behavior: CustomScrollBehavior(),
    child: Container(
      padding: EdgeInsets.symmetric(horizontal: 4),
      child: new ListView.builder(
        itemCount: items.length,
        itemBuilder: (BuildContext context, int index) {
          return Column(
            children: <Widget>[items[index]],
          );
        },
      ),
    ),
  );
}

Answer 1

好的，我解决了问题。只需在构建小部件时调用“setstate”即可。

  @protected
  @mustCallSuper
  void initState() {
    super.initState();
    Future.delayed(Duration.zero, () {
      //This setState is necessary because it refreshes the listView
      setState(() {});
    });
  }