更新 Firestore 文档时颤振屏幕导航回来

Question

我已经使用 StreamBuilder 在 ListView 中成功显示了用户列表。但是当我在 Firestore 中更新用户文档时，我的移动应用程序中的屏幕会自动返回。

这是我的屏幕流程。登录 -> 主页 -> 管理用户 -> 用户详细信息。 通过使用下面的代码，我在管理用户屏幕中创建了一个列表。现在我正在尝试在 firebase 控制台中更新用户名。更新数据后，ManageUsers 屏幕正在关闭。 Screen Rec

Widget build(BuildContext context) {
    return new StreamBuilder(
      stream: Firestore.instance.collection('users').snapshots(),
      builder: (context, AsyncSnapshot<QuerySnapshot> snapshot) {
        if (!snapshot.hasData)
          return Center(
            child: CircularProgressIndicator(),
          );
        if (snapshot.hasError)
          return Center(child: new Text('Error: ${snapshot.error}'));
        final int itemsCount = snapshot.data.documents.length;
        switch (snapshot.connectionState) {
          case ConnectionState.none:
            // TODO: Handle this case.
            return new CircularProgressIndicator();
            break;
          case ConnectionState.waiting:
            // TODO: Handle this case.
            return new CircularProgressIndicator();
            break;
          default:
            return new ListView.builder(
              scrollDirection: Axis.vertical,
              shrinkWrap: true,
              itemCount: itemsCount,
              addAutomaticKeepAlives: true,
              itemBuilder: (BuildContext context, int index) {
                final DocumentSnapshot document =
                    snapshot.data.documents[index];

                return new ListTile(
                  title: new Text(document['first_name']),
                  subtitle: new Text(document['last_name']),
                  onTap: () => {openUserDetailsScreen(document, context)},
                );
              },
            );
        }
      },
    );
  }

实际上它应该在同一个屏幕中刷新数据，而不是向后导航。我在构建列表时做错了什么吗？

主屏幕代码

class HomeScreen extends StatefulWidget {
  HomeScreen({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomeScreenState createState() => _MyHomeScreenState();

}

class _MyHomeScreenState extends State<HomeScreen> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
        automaticallyImplyLeading: false,
        leading: Builder(
          builder: (context) =>
              IconButton(
                icon: new Icon(Icons.menu),
                onPressed: () => Scaffold.of(context).openDrawer(),
              ),
        ),
      ),
      drawer: MyDrawer(widget.title),
      body: Center(
        child: Text("Home Screen"),
      ),
    );
  }

  @override
  void initState() {
    print('in home page ${globals.loggedInUser.firstName}');
  }
}

从主页我通过抽屉导航到 ManageUsers 屏幕。这是抽屉的代码。

class MyDrawer extends StatelessWidget {
  MyDrawer(this.currentPage);

  final String currentPage;

  bool isAdmin = true;

  @override
  Widget build(BuildContext context) {
    var currentDrawer = Provider.of<DrawerStateInfo>(context).getCurrentDrawer;
    return Drawer(
      child: ListView(
        children: <Widget>[
          _CustomListTile(
              currentPage, globals.HOME_MENU_TITLE, currentDrawer),
          _CustomListTile(
              currentPage, globals.LOGIN_MENU_TITLE, currentDrawer),
          ConditionalBuilder(
            condition: isAdmin,
            builder: (context) => _CustomListTile(currentPage,
                globals.MANAGE_USERS_MENU_TITLE, currentDrawer),
          )
        ],
      ),
    );
  }
}

class _CustomListTile extends StatelessWidget {
  final String currentPage;
  final String tileTitle;
  final currentDrawer;

  _CustomListTile(this.currentPage, this.tileTitle, this.currentDrawer);

  @override
  Widget build(BuildContext context) {
    return ListTile(
        title: Text(
          tileTitle,
          style: currentDrawer == 1
              ? TextStyle(fontWeight: FontWeight.bold)
              : TextStyle(fontWeight: FontWeight.normal),
        ),
        onTap: () {
          Navigator.of(context).pop();
          if (this.currentPage == tileTitle) return;
          Provider.of<DrawerStateInfo>(context).setCurrentDrawer(1);

          switch (tileTitle) {
            case globals.HOME_MENU_TITLE:
              {
                Navigator.of(context).pushReplacement(MaterialPageRoute(
                    builder: (BuildContext context) => HomeScreen(
                          title: globals.HOME_MENU_TITLE,
                        )));
                break;
              }

            case globals.LOGIN_MENU_TITLE:
              {
                Navigator.of(context).pushReplacement(MaterialPageRoute(
                    builder: (BuildContext context) => LoginScreen(
                          title: globals.LOGIN_MENU_TITLE,
                        )));
                break;
              }

            case globals.MANAGE_USERS_MENU_TITLE:
              {
                Navigator.of(context).pushNamed("/ManageUsers");
                break;
              }
            default:
              {
                break;
              }
          }
        });
  }
}

Answer 1

ListView StreamBuilder 意味着它会监听你的集合。 当您移动到下一个屏幕时，请移除监听器。

Answer 2

这段代码在我看来是错误的：

Provider.of<DrawerStateInfo>(context).setCurrentDrawer(1);

你应该有类似枚举甚至 tileTitle 之类的东西来用作抽屉上当前选定选项的保存状态，否则，你只知道有一个选定的选项，但不知道是哪个选项。

这会导致你调用错误路由的这种疯狂行为。

试试这样的

class MyDrawer extends StatelessWidget {
  MyDrawer(this.currentPage);

  final String currentPage;

  bool isAdmin = true;

  @override
  Widget build(BuildContext context) {
    return Drawer(
      child: ListView(
        children: <Widget>[
          _CustomListTile(currentPage, globals.HOME_MENU_TITLE),
          _CustomListTile(currentPage, globals.LOGIN_MENU_TITLE),
          isAdmin
              ? _CustomListTile(currentPage, globals.MANAGE_USERS_MENU_TITLE)
              : Container(),
        ],
      ),
    );
  }
}

class _CustomListTile extends StatelessWidget {
  final String currentPage;
  final String tileTitle;

  _CustomListTile(
    this.currentPage,
    this.tileTitle,
  );

  @override
  Widget build(BuildContext context) {
    return Consumer<DrawerStateInfo>(
      builder: (context, draweStateInfo, _) {

        final currentSelectedItem = draweStateInfo.getCurrentDrawer();

        return ListTile(
            title: Text(
              tileTitle,
              style: currentSelectedItem == tileTitle
                  ? TextStyle(fontWeight: FontWeight.bold)
                  : TextStyle(fontWeight: FontWeight.normal),
            ),
            onTap: () {
              Navigator.of(context).pop();

              if (currentSelectedItem == tileTitle) return;
              draweStateInfo.setCurrentDrawer(tileTitle);

              switch (currentSelectedItem) {
                case globals.HOME_MENU_TITLE:
                  {
                    Navigator.of(context).pushReplacement(MaterialPageRoute(
                        builder: (BuildContext context) => HomeScreen(
                          title: globals.HOME_MENU_TITLE,
                        )));
                    break;
                  }

                case globals.LOGIN_MENU_TITLE:
                  {
                    Navigator.of(context).pushReplacement(MaterialPageRoute(
                        builder: (BuildContext context) => LoginScreen(
                          title: globals.LOGIN_MENU_TITLE,
                        )));
                    break;
                  }

                case globals.MANAGE_USERS_MENU_TITLE:
                  {
                    Navigator.of(context).pushNamed("/ManageUsers");
                    break;
                  }
                default:
                  {
                    break;
                  }
              }
            });
      },
    );
  }
}