🙉 🎻 🍘 Flutter中导航的详细分类 🤪 🗺️ 🍅

Flutter在开发人员中越来越受欢迎。大多数构建应用程序的方法已经建立，并且每天都在电子商务应用程序的开发中使用。导航主题降为背景或第三计划。框架提供什么导航API？已经开发出什么方法？这些方法如何使用？它们有什么用？

介绍

让我们从导航开始。导航是一种允许您在具有指定参数的用户界面之间导航的方法。

例如，在IOS世界中，它组织导航UIViewController，而在Android中-导航组件。Flutter提供了什么？

航海家

Flutter中的屏幕称为路由。为了在路线之间移动，有一个Navigator类，该类具有用于实现各种类型导航的扩展API。

导航至新路线并从中返回

让我们开始简单。通过push（）方法调用到新屏幕（路线）的导航，该方法带有一个参数-这是Route。

Navigator.push(MaterialPageRoute(builder: (BuildContext context) => MyPage()));

让我们仔细看一下push方法调用：

Navigator — , .

Navigator.push() — route .

MaterialPageRoute() — route, .

builder — MaterialPageRoute, .

MyPage — Stateful/Stateless Widget

route

pop().

Navigator.pop();

builder . Navigator, build.

Navigator.push(context, MaterialPageRoute(builder: (context) => MyPage(someData: data)));

MyPage ( ).

pop() .

Navigator.pop(data);

Navigator State

Navigator, MaterialApp/CupertinoApp/WidgetsApp. State API .

Stack. "call flow" NavigatorState.

vs

. route, .

, — ?

: , . .

, — ?

: , .

Imperative vs Declarative Programming

. . Route. Flutter route, MaterialPageRoute CupertinoPageRoute. CupertinoPageRoute title, settings.

Navigator.push(
    context,
    CupertinoPageRoute<T>(
        title: "Setting",
        builder: (BuildContext context) => MyPage(),
        settings: RouteSettings(name:"my_page"),
    ),
);

route ViewModel/Controller/BLoC/… .

MyPage CupertinoPageRoute. push .

, route .

. .

Navigator.pushNamed(context, '/my_page');

. " " .

MaterialApp/CupertinoApp/WidgetsApp. 2 onGenerateRoute onUnknownRoute .

MaterialApp(
    onUnknownRoute: (settings) => CupertinoPageRoute(
      builder: (context) {
                return UndefinedView(name: settings.name);
            }
    ),
  onGenerateRoute: (settings) {
    if (settings.name == '\my_page') {
      return CupertinoPageRoute(
                title: "MyPage",
                settings: settings,
        builder: (context) => MyPage(),
      );
    }
        //     
  },
);

:

onGenerateRoute — Navigator.pushNamed(). route.

onUnknownRoute — onGenerateRoute null. route, web — 404 page.

. , .

. .

showAboutDialog
showBottomSheet
showDatePicker
showGeneralDialog
showMenu
showModalBottomSheet
showSearch
showTimePicker
showCupertinoDialog
showDialog
showLicensePage
showCupertinoModalPopup

. API, .

?

, showGeneralDialog.

Future<T> showGeneralDialog<T>({
  @required BuildContext context,
  @required RoutePageBuilder pageBuilder,
  bool barrierDismissible,
  String barrierLabel,
  Color barrierColor,
  Duration transitionDuration,
  RouteTransitionsBuilder transitionBuilder,
  bool useRootNavigator = true,
  RouteSettings routeSettings,
}) {
  assert(pageBuilder != null);
  assert(useRootNavigator != null);
  assert(!barrierDismissible || barrierLabel != null);
  return Navigator.of(context, rootNavigator: useRootNavigator).push<T>(_DialogRoute<T>(
    pageBuilder: pageBuilder,
    barrierDismissible: barrierDismissible,
    barrierLabel: barrierLabel,
    barrierColor: barrierColor,
    transitionDuration: transitionDuration,
    transitionBuilder: transitionBuilder,
    settings: routeSettings,
  ));
}

. showGeneralDialog push NavigatorState _DialogRoute(). , .

— route .

route

"every thins is a route", . , route .

route Flutter — PageRoute PopupRoute.

PageRoute — route, .

PopupRoute — route, route.

PageRoute:

MaterialPageRoute
CupertinoPageRoute
_SearchPageRoute
PageRouteBuilder

PopupRoute:

_ContexMenuRoute
_DialogRoute
_ModalBottomSheetRoute
_CupertinoModalPopupRoute
_PopupMenuRoute

PopupRoute , .

, .

Best practices

, " ?". , API , . .

.
BuildContext ( , BuildContext).
. route, CupertinoPageRoute, BottomSheetRoute, DialogRoute ..

abstract class IRouter {
  Future<T> routeTo<T extends Object>(RouteBundle bundle);
  Future<bool> back<T extends Object>({T data, bool rootNavigator});
  GlobalKey<NavigatorState> rootNavigatorKey;
}

:

routeTo - .

back — .

rootNavigatorKey — GlobalKey NavigatorState.

, .

class Router implements IRouter {
    @override
  GlobalKey<NavigatorState> rootNavigatorKey = GlobalKey<NavigatorState>();

    @override
  Future<T> routeTo<T>(RouteBundle bundle) async {
   // Push logic here
  }

    @override
  Future<bool> back<T>({T data, bool rootNavigator = false}) async {
        // Back logic here
    }
}

, routeTo().

@override
  Future<T> routeTo<T>(RouteBundle bundle) async {
        assert(bundle != null, "The bundle [RouteBundle.bundle] is null");
    NavigatorState rootState = rootNavigatorKey.currentState;
    assert(rootState != null, 'rootState [NavigatorState] is null');

    switch (bundle.route) {
      case "/routeExample":
        return await rootState.push(
          _buildRoute<T>(
            bundle: bundle,
            child: RouteExample(),
          ),
        );

      case "/my_page":
        return await rootState.push(
          _buildRoute<T>(
            bundle: bundle,
            child: MyPage(),
          ),
        );
      default:
        throw Exception('Route is not found');
    }
  }

root NavigatorState ( WidgetsApp) push RouteBundle .

RouteBundle. , .

enum ContainerType {
  /// The parent type is [Scaffold].
  ///
  /// In IOS route with an iOS transition [CupertinoPageRoute].
  /// In Android route with an Android transition [MaterialPageRoute].
  ///
  scaffold,

  /// Used for show child in dialog.
  ///
  /// Route with [DialogRoute].
  dialog,

  /// Used for show child in [BottomSheet].
  ///
  /// Route with [ModalBottomSheetRoute].
  bottomSheet,

  /// Used for show child only.
  /// [AppBar] and other features is not implemented.
  window,
}
class RouteBundle {
  /// Creates a bundle that can be used for [Router].
  RouteBundle({
    this.route,
    this.containerType,
  });

  /// The route for current navigation.
  ///
  /// See [Routes] for details.
  final String route;

  /// The current status of this animation.
  final ContainerType containerType;
}

enum ContainerType — , .

RouteBundle — - route.

_buildRoute. , route .

Route<T> _buildRoute<T>({@required RouteBundle bundle, @required Widget child}) {
    assert(bundle.containerType != null, "The bundle.containerType [RouteBundle.containerType] is null");

    switch (bundle.containerType) {
      case ContainerType.scaffold:
        return CupertinoPageRoute<T>(
          title: bundle.title,
          builder: (BuildContext context) => child,
          settings: RouteSettings(name: bundle.route),
        );
      case ContainerType.dialog:
        return DialogRoute<T>(
          title: '123',
          settings: RouteSettings(name: bundle.route),
          pageBuilder: (BuildContext context, Animation<double> animation, Animation<double> secondaryAnimation) {
                        return child;
                    },
        );
      case ContainerType.bottomSheet:
        return ModalBottomSheetRoute<T>(
          settings: RouteSettings(name: bundle.route),
          isScrollControlled: true,
          builder: (BuildContext context) => child,
        );
      case ContainerType.window:
        return CupertinoPageRoute<T>(
          settings: RouteSettings(name: bundle.route),
          builder: (BuildContext context) => child,
        );
      default:
        throw Exception('ContainerType is not found');
    }
  }

ModalBottomSheetRoute DialogRoute, . route Material Flutter.

back.

@override
Future<bool> back<T>({T data, bool rootNavigator = false}) async {
    NavigatorState rootState = rootNavigatorKey.currentState;
  return await (rootState).maybePop<T>(data);
}

rootNavigatorKey App :

MaterialApp(
    navigatorKey: widget.router.rootNavigatorKey,
    home: Home()
);

, route. - "" , , Dependency Injection.

router.routeTo(RouteBundle(route: '/my_page', containerType: ContainerType.window));

, :

BuildContext GlobalKey
route View

Flutter , .

:

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Flutter

Flutter中导航的详细分类

介绍

航海家

导航至新路线并从中返回

route

Navigator State

vs

?

route

Best practices

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