flutter - 显示键盘时如何隐藏cupertinoTabBar？或者如何让键盘盖住酒吧？或者始终将标签栏保持在底部？

Question

我在我的 flutter 应用程序中使用 CupertinoTabBar。问题是 bottomBar 在键盘出现时显示，但它不应该出现。它是一个底部栏，它应该始终在底部。

我还没有找到执行此操作的方法或技巧。也许有人可以指导我获得正确的行为。

这是我的 flutter doctor 输出

医生摘要(要查看所有详细信息，请运行 flutter doctor -v):

[✓] Flutter (Channel master, v1.6.1-pre.50, on Linux, locale en_US.UTF-8)

[✓] Android 工具链 - 为 Android 设备开发(Android SDK 版本 28.0.3)

[✓] Android Studio(3.3 版)

[✓] VS 代码(版本 1.33.1)

[✓] 连接的设备(1 个可用)

这是 cupertinoTabBar 允许的唯一选项:

const CupertinoTabBar({
    Key key,
    @required this.items,
    this.onTap,
    this.currentIndex = 0,
    this.backgroundColor,
    this.activeColor,
    this.inactiveColor = CupertinoColors.inactiveGray,
    this.iconSize = 30.0,
    this.border = const Border(
      top: BorderSide(
        color: _kDefaultTabBarBorderColor,
        width: 0.0, // One physical pixel.
        style: BorderStyle.solid,
      ),
    ),
  })

这是当键盘出现时我的 CupertinoTabBar 上升的方式:

更新:

我正在尝试验证键盘的状态是否不显示 cupertinoTabBar，但它位于 CupertinoTabScaffold 中:

return Scaffold(
    body: CupertinoTabScaffold(
      tabBuilder: (BuildContext context, int index) {
        switch (index) {
          case 0: // Home
            return CupertinoTabView(
              navigatorKey: Undoc3Keys.homeNavigator,
              routes: getRoutes(context, store),
              onGenerateRoute: handleRoutes,
              builder: (BuildContext context) => FeedScreen(),
            );
            break;
          case 1: // Preguntar
            return CupertinoTabView(
              navigatorKey: Undoc3Keys.askNavigator,
              routes: getRoutes(context, store),
              onGenerateRoute: handleRoutes,
              builder: (BuildContext context) => SearchResultScreen(
                    arguments: {"askScreen": ""},
                  ),
            );
            break;
          case 2: // Perfil
            return CupertinoTabView(
              navigatorKey: Undoc3Keys.perfilNavigator,
              routes: getRoutes(context, store),
              onGenerateRoute: handleRoutes,
              builder: (BuildContext context) => ProfileScreen(),
            );
            break;
          default:
        }
      },
      tabBar: Undoc3Keys.keyboardStatus // Here is validation of keyboard.
          ? CupertinoTabBar( // A try for making invisible bar.
              items: <BottomNavigationBarItem>[
                BottomNavigationBarItem(
                    icon: Icon(
                      Icons.radio_button_unchecked,
                      color: Colors.transparent,
                    ),
                    backgroundColor: Colors.transparent),
                BottomNavigationBarItem(
                    icon: Icon(
                      Icons.radio_button_unchecked,
                      color: Colors.transparent,
                    ),
                    backgroundColor: Colors.transparent)
              ],
              backgroundColor: Colors.transparent.withOpacity(0.0),
              inactiveColor: Colors.transparent,
              activeColor: Colors.transparent,
              border: Border(
                top: BorderSide(
                  color: Colors.transparent,
                  width: 0.0, // One physical pixel.
                  style: BorderStyle.none,
                ),
              ),
            )
          : _buildTabBar(),
    ),
  );

键盘出现时是这样显示的:

Answer 1

如果将 CupertinoTabBar 放在 Scaffold 的属性 bottomNavigationBar 中，它应该能够在键盘打开时自动消失，所以我假设在您的情况下不可能这样做。

首先，你得知道键盘是开着还是不开着。插件keyboard_visibility可以帮助您。

有了这些信息，您必须决定是否要显示 CupertinoTabBar。

class Foo extends StatefulWidget {
  @override
  _FooState createState() => _FooState();
}

class _FooState extends State<Foo> {
  bool isKeyboardVisible;

  @override
  void initState() {
    super.initState();
    isKeyboardVisible = false;
    KeyboardVisibilityNotification().addNewListener(
      onChange: (isVisible) {
        setState(() => isKeyboardVisible = isVisible);
      },
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Column(
        crossAxisAlignment: CrossAxisAlignment.center,
        mainAxisSize: MainAxisSize.max,
        mainAxisAlignment: MainAxisAlignment.end,
        children: [
          TextField(),
          SizedBox(height: 50),
          isKeyboardVisible ? SizedBox() : CupertinoTabBar(
            items: [
              BottomNavigationBarItem(
                icon: Icon(Icons.airline_seat_flat_angled),
                title: Text('Item #1'),
              ),
              BottomNavigationBarItem(
                icon: Icon(Icons.airline_seat_flat),
                title: Text('Item #2'),
              ),
              BottomNavigationBarItem(
                icon: Icon(Icons.airline_seat_individual_suite),
                title: Text('Item #3'),
              ),
            ],
          ),
        ],
      ),
    );
  }
}

更新

你的情况有点棘手。在这种情况下，我认为更好的选择是创建一个不可见的 CupertinoTabBar:

class InvisibleCupertinoTabBar extends CupertinoTabBar {
  static const dummyIcon = Icon(IconData(0x0020));

  InvisibleCupertinoTabBar()
      : super(
          items: [
            BottomNavigationBarItem(icon: dummyIcon),
            BottomNavigationBarItem(icon: dummyIcon),
          ],
        );

  @override
  Size get preferredSize => const Size.square(0);

  @override
  Widget build(BuildContext context) => SizedBox();

  @override
  InvisibleCupertinoTabBar copyWith({
    Key key,
    List<BottomNavigationBarItem> items,
    Color backgroundColor,
    Color activeColor,
    Color inactiveColor,
    Size iconSize,
    Border border,
    int currentIndex,
    ValueChanged<int> onTap,
  }) => InvisibleCupertinoTabBar();
}

当键盘可见时，只显示此小部件。

isKeyboardVisible ? InvisibleCupertinoTabBar() : CupertinoTabBar(
  ...
),