add router and welcome page

ui/lib/main.dart

@@ -1,18 +1,65 @@
 import 'package:flutter/material.dart';
+import 'package:go_router/go_router.dart';
 import 'package:ui/navdrawer.dart';
 import 'package:ui/search.dart';
+import 'package:ui/weclome.dart';
 
 void main() {
-  runApp(const MyApp());
+  runApp(MyApp());
 }
 
 class MyApp extends StatelessWidget {
-  const MyApp({super.key});
+  final GlobalKey<NavigatorState> _rootNavigatorKey =
+      GlobalKey<NavigatorState>();
+
+  MyApp({super.key});
 
   // This widget is the root of your application.
   @override
   Widget build(BuildContext context) {
-    return MaterialApp(
+    // GoRouter configuration
+    final _shellRoute = ShellRoute(
+      builder: (BuildContext context, GoRouterState state, Widget child) {
+        return Scaffold(
+             appBar: AppBar(
+              // TRY THIS: Try changing the color here to a specific color (to
+              // Colors.amber, perhaps?) and trigger a hot reload to see the AppBar
+              // change color while the other colors stay the same.
+              backgroundColor: Theme.of(context).colorScheme.inversePrimary,
+              // Here we take the value from the MyHomePage object that was created by
+              // the App.build method, and use it to set our appbar title.
+              title: const Text("Polaris追剧"),
+            ),
+            body: Center(
+                // Center is a layout widget. It takes a single child and positions it
+                // in the middle of the parent.
+                child: Row(children: <Widget>[
+              NavDrawer(),
+              const VerticalDivider(thickness: 1, width: 1),
+              Expanded(child: child)
+            ])));
+      },
+      routes: [
+        GoRoute(
+          path: '/',
+          builder: (context, state) => WelcomePage(),
+        ),
+        GoRoute(
+          path: "/search",
+          builder: (context, state) => const SearchPage(),
+        )
+      ],
+    );
+
+    final _router = GoRouter(
+      navigatorKey: _rootNavigatorKey,
+      initialLocation: '/',
+      routes: [
+        _shellRoute,
+      ],
+    );
+
+    return MaterialApp.router(
       title: 'Flutter Demo',
       theme: ThemeData(
         // This is the theme of your application.
@@ -30,79 +77,10 @@ class MyApp extends StatelessWidget {
         //
         // This works for code too, not just values: Most code changes can be
         // tested with just a hot reload.
-        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
+        colorScheme: ColorScheme.fromSeed(seedColor: Colors.lightBlueAccent),
         useMaterial3: true,
       ),
-      home: const MyHomePage(title: 'Flutter Demo Home Page'),
-    );
-  }
-}
-
-class MyHomePage extends StatefulWidget {
-  const MyHomePage({super.key, required this.title});
-
-  // This widget is the home page of your application. It is stateful, meaning
-  // that it has a State object (defined below) that contains fields that affect
-  // how it looks.
-
-  // This class is the configuration for the state. It holds the values (in this
-  // case the title) provided by the parent (in this case the App widget) and
-  // used by the build method of the State. Fields in a Widget subclass are
-  // always marked "final".
-
-  final String title;
-
-  @override
-  State<MyHomePage> createState() => _MyHomePageState();
-}
-
-class _MyHomePageState extends State<MyHomePage> {
-  int _counter = 0;
-
-  void _incrementCounter() {
-    setState(() {
-      // This call to setState tells the Flutter framework that something has
-      // changed in this State, which causes it to rerun the build method below
-      // so that the display can reflect the updated values. If we changed
-      // _counter without calling setState(), then the build method would not be
-      // called again, and so nothing would appear to happen.
-      _counter++;
-    });
-  }
-
-  @override
-  Widget build(BuildContext context) {
-    // This method is rerun every time setState is called, for instance as done
-    // by the _incrementCounter method above.
-    //
-    // The Flutter framework has been optimized to make rerunning build methods
-    // fast, so that you can just rebuild anything that needs updating rather
-    // than having to individually change instances of widgets.
-    return Scaffold(
-      appBar: AppBar(
-        // TRY THIS: Try changing the color here to a specific color (to
-        // Colors.amber, perhaps?) and trigger a hot reload to see the AppBar
-        // change color while the other colors stay the same.
-        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
-        // Here we take the value from the MyHomePage object that was created by
-        // the App.build method, and use it to set our appbar title.
-        title: Text(widget.title),
-      ),
-      body: Center(
-          // Center is a layout widget. It takes a single child and positions it
-          // in the middle of the parent.
-          child: Row(
-        children: <Widget>[
-          NavDrawer(),
-          const VerticalDivider(thickness: 1, width: 1),
-          SearchPage(),
-        ],
-      )),
-      floatingActionButton: FloatingActionButton(
-        onPressed: _incrementCounter,
-        tooltip: 'Increment',
-        child: const Icon(Icons.add),
-      ), // This trailing comma makes auto-formatting nicer for build methods.
+      routerConfig: _router,
     );
   }
 }