flutter - 在 Flutter 中创建私有(private)路由

Question

如何在我的私有(private)路由上创建一个包装器，仅当用户被授权时才导航到屏幕，否则重定向到登录并在登录后返回原始屏幕。
如何以一种通用的方式实现这一点，以便我在其他私有(private) future 屏幕上重复使用它？

Answer 1

如果您使用 routes MaterialApp 中的参数，您可以将其替换为以下实现

import 'dart:collection';

import 'package:flutter/widgets.dart';

class ConditionalRouter extends MapMixin<String, WidgetBuilder> {
  final Map<String, WidgetBuilder> public;
  final Map<String, WidgetBuilder> private;

  ConditionalRouter({this.public, this.private});

  @override
  WidgetBuilder operator [](Object key) {
    if (public.containsKey(key))
      return public[key];
    if (private.containsKey(key)) {
      if (MyAuth.isUserLoggedIn)
        return private[key];
      // Adding next page parameter to your Login page
      // will allow you to go back to page, that user were going to
      return (context) => LoginPage(nextPage: key);
    }
    return null;
  }

  @override
  void operator []=(key, value) {}

  @override
  void clear() {}

  @override
  Iterable<String> get keys {
    final set = Set<String>();
    set.addAll(public.keys);
    set.addAll(private.keys);
    return set;
  }

  @override
  WidgetBuilder remove(Object key) {
    return public[key] ?? private[key];
  }
}

并像这样使用它:

MaterialApp(
  // ...
  routes: ConditionalRouter(
    public: {
      '/start_page': (context) => StartPage()
    },
    private: {
      '/user_profile': (context) => UserProfilePage()
    }
  )
)