說明

很多時(shí)候我們需要對(duì)是否登錄進(jìn)行校驗(yàn)伸眶，有些頁(yè)面假如沒有登錄的話惊窖，不能進(jìn)行跳轉(zhuǎn)，要先跳轉(zhuǎn)登錄頁(yè)厘贼，這里我們使用getx來實(shí)現(xiàn)路由的重定向

代碼實(shí)現(xiàn)

這里我們使用GetPage中間件（middlewares）來實(shí)現(xiàn)界酒，首先我們需要先繼承GetMiddleware實(shí)現(xiàn)自己的MyGetMiddleware，然后重寫redirect方法嘴秸，進(jìn)行校驗(yàn)并返回對(duì)應(yīng)的對(duì)象盾计，如果校驗(yàn)成功返回null即可就是走默認(rèn)的路由，如果校驗(yàn)失敗就返回RouteSettings對(duì)象重定向登錄頁(yè)（這里我用隨機(jī)數(shù)來模擬校驗(yàn)）

class MyGetMiddleware extends GetMiddleware{
  @override
  RouteSettings? redirect(String? route) {
    return Random().nextInt(2) == 1 ? RouteSettings(name: '/login') : null;
  }
}

然后我們?cè)谂渲肎etPages的時(shí)候?qū)π枰ｒ?yàn)的頁(yè)面設(shè)置中間件（這里我對(duì)SecondPage進(jìn)行校驗(yàn)）

class MyApp extends StatelessWidget {
  const MyApp({super.key});
  @override
  Widget build(BuildContext context) {
    return GetMaterialApp(
        initialRoute: '/',
        getPages: [
          GetPage(name: '/', page: () => const MyHomePage(title: 'Flutter Demo Home Page')),
          GetPage(name: '/second', page: () => SecondPage(),middlewares: [MyGetMiddleware()]),
          GetPage(name: '/login', page: () => LoginPage()),
        ],
        title: 'Flutter Demo',
        theme: ThemeData(
          colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
          useMaterial3: true,
        )
    );
  }
}

完整代碼如下

import 'dart:math';

import 'package:flutter/material.dart';
import 'package:get/get.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});
  @override
  Widget build(BuildContext context) {
    return GetMaterialApp(
        initialRoute: '/',
        getPages: [
          GetPage(name: '/', page: () => const MyHomePage(title: 'Flutter Demo Home Page')),
          GetPage(name: '/second', page: () => SecondPage(),middlewares: [MyGetMiddleware()]),
          GetPage(name: '/login', page: () => LoginPage()),
        ],
        title: 'Flutter Demo',
        theme: ThemeData(
          colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
          useMaterial3: true,
        )
    );
  }
}

class Controller extends GetxController{
  var count = 0.obs;
  increment() => count++;
}

class MyGetMiddleware extends GetMiddleware{
  @override
  RouteSettings? redirect(String? route) {
    return Random().nextInt(2) == 1 ? RouteSettings(name: '/login') : null;
  }
}


class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  // 使用Get.put()實(shí)例化你的類赁遗，使其對(duì)當(dāng)下的所有子路由可用署辉。
  final Controller c = Get.put(Controller());
  int _counter = 0;

  Future<void> _showMyDialog() async {
    return showDialog<void>(
      context: context,
      barrierDismissible: false, // user must tap button!
      builder: (BuildContext context) {
        return Dialog(
          shape: RoundedRectangleBorder(
              borderRadius: BorderRadius.all(Radius.circular(5))
          ),
          child: Container(
            height: 200,
            decoration: BoxDecoration(
                borderRadius: BorderRadius.all(Radius.circular(5)),
                color: Colors.white
            ),
            padding: EdgeInsets.fromLTRB(15, 20, 15, 20),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.center,
              children: <Widget>[
                Text('添加標(biāo)簽', style: TextStyle(color: Colors.black, fontSize: 16),),
                SizedBox(height: 20,),
                Container(
                  height: 40,
                  decoration: BoxDecoration(
                      color: Color(0xFFF6F6F6),
                      borderRadius: BorderRadius.all(Radius.circular(10))
                  ),
                )
              ],
            ),
          ),
        );
      },
    );
  }

  void _incrementCounter() async{
    Get.toNamed('/second');
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Expanded(child: Container(
              color: Colors.blue,
              child: Obx(() => Text("Clicks: ${c.count}")),
            )),
            Container(
              width: 200,
              child: AspectRatio(
                aspectRatio: 2,
                child: Image.asset("assets/images/ic_test.png",fit: BoxFit.fill,),
              ),
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}

class SecondPage extends StatelessWidget {
  // 你可以讓Get找到一個(gè)正在被其他頁(yè)面使用的Controller，并將它返回給你岩四。
  final Controller c = Get.find();
  SecondPage({super.key});

  @override
  Widget build(BuildContext context) {
    // 訪問更新后的計(jì)數(shù)變量
    return Scaffold(
        body: Center(
            child: Column(
              children: [
                Obx(()=>
                    Text("${c.count}")
                ),
                ElevatedButton(onPressed: ()=>{
                  c.increment()
                }, child: Text("點(diǎn)擊"))
              ],
            )
        )
    );
  }
}

class LoginPage extends StatelessWidget {
  LoginPage({super.key});

  @override
  Widget build(BuildContext context) {
    // 訪問更新后的計(jì)數(shù)變量
    return Scaffold(
        body: Center(
            child:Text(
              "登錄",style: TextStyle(fontSize: 50),
            )
        )
    );
  }
}