回答編集履歴

追記

2020/06/18 05:34

投稿

tepci

スコア419

test CHANGED Viewed

@@ -1,5 +1,7 @@
 推測ですが、その方法はTabBarViewなどの画面切り替えでしか使えず、Navigatorを使用した画面遷移ではできないようです。
+ただ、以下のようにすれば実現可能です。
 ```
@@ -99,3 +101,523 @@
 [ここ](https://stackoverflow.com/questions/51195114/flutter-persistent-state-between-pages)を参考にしてください。
+また、すごい雑ですが、以下のソースをまるごとコピーして、[DartPad](https://dartpad.dev/flutter)に張り付けて実行してみてください。
+```
+import 'package:flutter/material.dart';
+void main() => runApp(new MyApp());
+PageStorageKey mykey = new PageStorageKey("testkey");
+final PageStorageBucket _bucket = new PageStorageBucket();
+class MyApp extends StatelessWidget{
+  final title = 'Flutter サンプル';
+  @override
+  Widget build(BuildContext context){
+    return MaterialApp(
+      title: 'Flutter Demo',
+      home: PageStorage(
+        bucket: _bucket,
+        key: mykey,
+        child: MyHomePage(
+          title:this.title,
+        ),
+      ),
+    );
+  }
+}
+class MyHomePage extends StatefulWidget{
+  MyHomePage({Key key, this.title}) : super(key: key);
+  final String title;
+  @override
+  _MyHomePageState createState() => new _MyHomePageState();
+}
+//インスタンスからウィジェットを作る
+class _MyHomePageState extends State<MyHomePage>{
+  bool _checked1 = false;
+  bool result;
+  @override
+  Widget build(BuildContext context){
+    return Scaffold(
+      appBar: AppBar(
+        title: Text('課題管理App（曜日別）')
+      ),
+      body: Container(
+        child: ListView(
+          children: <Widget>[
+            ListTile(
+              title: Text('月曜締め切り'),
+              trailing:  Icon(Icons.arrow_forward_ios),
+              onTap: (){
+                Navigator.push(
+                  context,
+                  MaterialPageRoute(
+                    builder:  (context) => MondayPage(),
+                  )
+                );
+            },
+            ),
+            ListTile(
+              title: Text('金曜締め切り'),
+              trailing:  Icon(Icons.arrow_forward_ios),
+              onTap: (){
+                 Navigator.push(
+                    context,
+                    MaterialPageRoute(
+                      builder:  (context) => MyHomePageF(),
+                    )
+                );
+              },
+            ),
+            Text('備考欄'),
+            TextField(
+              autofocus: true,
+              decoration: InputDecoration(
+                hintText: '臨時課題があれば記入'
+              ),
+            ),
+            Row(
+              children: <Widget>[
+                Checkbox(
+                  value:  _checked1,
+                  onChanged: (bool value) {
+                    setState(() {
+                      _checked1 = value;
+                    });
+                  },
+                ),
+                Text('全課題クリア！')
+              ],
+            )
+          ],
+        ),
+      )
+    );
+  }
+}
+class MyHomePageF extends StatefulWidget{
+  @override
+  State<StatefulWidget> createState() {
+    return _MyHomePageFState();
+  }
+}
+class FridayPageParams {
+  bool _checked1= false ;
+}
+class _MyHomePageFState extends State<MyHomePageF>{
+  FridayPageParams _params;
+  @override
+  void didChangeDependencies() { // このメソッドをオーバーライド
+    FridayPageParams p = _bucket.readState(context, identifier: ValueKey(mykey));
+    print(p);
+    if (p != null) {
+      _params = p;
+    } else {
+      _params = FridayPageParams();
+      print(_params._checked1);
+    }
+    super.didChangeDependencies();
+  }
+  Widget build(BuildContext context){
+    return Scaffold(
+      appBar: AppBar(
+        title: Text('金曜締め切り'),
+      ),
+      body: Column(
+        mainAxisAlignment: MainAxisAlignment.start,
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: <Widget>[
+          Text(
+            '応用数学   ',
+            style: TextStyle(fontSize: 16.0),
+          ),
+          Row(
+            children: <Widget>[
+              Checkbox(
+                value:  _params._checked1,
+                onChanged: (bool value) {
+                  setState(() {
+                    _params._checked1 = value;
+                  });
+                  _bucket.writeState(context, _params, identifier: ValueKey(mykey));
+                },
+              ),
+              Text('提出済み',)
+            ],
+          ),
+          Text('備考欄'),
+          TextField(
+            autofocus: true,
+            decoration: InputDecoration(
+                hintText: '特記事項があれば記入'
+            ),
+          ),
+          RaisedButton(
+            onPressed: (){
+              Navigator.pop(context,);
+            },
+            child: Center(child: Text('戻る')),
+          )
+        ],
+      ) ,
+    );
+  }
+}
+class MondayPage extends StatelessWidget{
+  @override
+  Widget build(BuildContext context) {
+    return
+      new  MyHomePageM(
+    );
+  }
+}
+class MyHomePageM extends StatefulWidget{
+  MyHomePageM({this.title}): super();
+  final String title;
+  @override
+  _MyHomePageMState createState() => new _MyHomePageMState();
+}
+//インスタンスからウィジェットを作る
+class _MyHomePageMState extends State<MyHomePageM>{
+  @override
+  Widget build(BuildContext context){
+    return Scaffold(
+      appBar: AppBar(
+        title: Text('月曜締め切り'),
+      ),
+      body: Text('課題の入力')
+    );
+  }
+}
+```