{"id":610,"date":"2021-05-17T18:15:39","date_gmt":"2021-05-17T09:15:39","guid":{"rendered":"http:\/\/localhost:8000\/?p=610"},"modified":"2021-05-17T18:15:39","modified_gmt":"2021-05-17T09:15:39","slug":"share-state-between-other-routes","status":"publish","type":"post","link":"http:\/\/localhost:8000\/2021\/05\/share-state-between-other-routes.html","title":{"rendered":"Flutter\u3067\u5225\u753b\u9762\uff08route\uff09\u3067\u72b6\u614b\uff08state\uff09\u3092\u5171\u6709\u3059\u308b"},"content":{"rendered":"<p><img src=\"http:\/\/localhost:8000\/wp-content\/uploads\/2021\/04\/logo_lockup_flutter_horizontal-400x112.png\" alt=\"\" \/><\/p>\n<p>Flutter \u3067\u304a\u52c9\u5f37\u6642\u9593\u7ba1\u7406\u7528\u306e\u30bf\u30a4\u30de\u30fc\u30a2\u30d7\u30ea\u3092\u4f5c\u3063\u3066\u3044\u308b\u306e\u3067\u3059\u304c\u3001\u983b\u7e41\u306b\u30bf\u30a4\u30de\u30fc\u306e\u8d77\u52d5\uff0f\u505c\u6b62\u3057\u5fd8\u308c\u304c\u767a\u751f\u3059\u308b\u306e\u3067\u3001\u624b\u4f5c\u696d\u3067\u7d4c\u904e\u6642\u9593\u3092\u7de8\u96c6\u3067\u304d\u308b\u3088\u3046\u306b\u3057\u307e\u3057\u305f\u3002<br \/>\n\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u5225\u753b\u9762\u3067\u7de8\u96c6\u3059\u308b\u4f5c\u308a\u306a\u306e\u3067\u3059\u304c\u3001\u5225\u753b\u9762\uff08route\uff09\u3067\u4e0a\u624b\u304f\u5024\u3092\u3084\u308a\u53d6\u308a\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u3001\u305d\u306e\u5b9f\u88c5\u65b9\u6cd5\u3092\u4e8c\u3064\u307b\u3069\u8a66\u3057\u305f\u306e\u3067\u7d39\u4ecb\u3057\u307e\u3059\u3002<br \/>\n<img src=\"http:\/\/localhost:8000\/wp-content\/uploads\/2021\/05\/study_timer_edit_loop.gif\" alt=\"\" \/><\/p>\n<h2>StatefullWidget + \u753b\u9762\u9077\u79fb\u6642\u306b\u30d1\u30e9\u30e1\u30fc\u30bf\u6e21\u3057\u3059\u308b\u65b9\u6cd5<\/h2>\n<p>\u4e00\u3064\u76ee\u306e\u65b9\u6cd5\u306f\u3001<code>StatefullWidget<\/code>\u3067\u9077\u79fb\u5143\u753b\u9762\uff08route\uff09\u306e\u72b6\u614b\uff08state\uff09\u3092\u7ba1\u7406\u3057\u3064\u3064\u3001\u5225\u753b\u9762\u306b\u9077\u79fb\u3059\u308b\u969b\u306b\u30d1\u30e9\u30e1\u30fc\u30bf\u3092\u6e21\u3059\u65b9\u6cd5\u3067\u3059\u3002\u3053\u306e\u65b9\u6cd5\u3060\u3068\u9077\u79fb\u5143\u753b\u9762\u306e\u72b6\u614b\uff08state\uff09\u304c\u753b\u9762\u9077\u79fb\u6642\u306b\u7834\u68c4\u3055\u308c\u308b\u3082\u306e\u3060\u3068\u601d\u3063\u3066\u3044\u305f\u306e\u3067\u3059\u304c\u3001<code>maintainState=true<\/code>\u306e\u8a2d\u5b9a\u3067\u3042\u308c\u3070\u7834\u68c4\u3055\u308c\u306a\u3044\u3088\u3046\u306a\u306e\u3067\u3001\u7d50\u69cb\u4f7f\u3044\u52dd\u624b\u304c\u826f\u3055\u305d\u3046\u3067\u3059\u3002<\/p>\n<p>\u753b\u9762\u9077\u79fb\u306e\u5b9f\u88c5\u306f\u3001Flutter cookbook \u306e <a href=\"https:\/\/flutter.dev\/docs\/cookbook\/navigation\/navigation-basics\">Navigate to a new screen and back<\/a> \u3092\u53c2\u7167\u304f\u3060\u3055\u3044\u3002<\/p>\n<p>\u4eca\u56de\u306e\u30a2\u30d7\u30ea\u306e\u9077\u79fb\u5143\u753b\u9762\u306e\u753b\u9762\u9077\u79fb\u306b\u95a2\u9023\u3059\u308b\u5b9f\u88c5\u306f\u4ee5\u4e0b\u306e\u901a\u308a\u3067\u3059\u3002<\/p>\n<pre><code class=\"language-dart\">child: TextButton(\n  child: Text(&#039;edit&#039;),\n  onPressed: () async {\n    \/\/ EditPage\u306b\u9077\u79fb\u3057\u305f\u3057\u3001\u623b\u3063\u3066\u304d\u305f\u969b\u306b\u7d50\u679c\u3092result\u3067\u53d7\u3051\u53d6\u3063\u3066\u3044\u308b\n    final result = await Navigator.push(\n      context,\n      MaterialPageRoute(builder: (context) =&gt; EditPage(_studyTime, _playTime), maintainState: false, fullscreenDialog: true), \/\/ EditPage\u306b\u9077\u79fb\u3059\u308b\u969b\u306b\u3001 _studyTime \u3068 _playTime \u3092\u6e21\u3057\u3066\u3044\u308b\n    );\n\n    \/\/ \u7d50\u679c\u304c\u306a\u3051\u308c\u3070\u4f55\u3082\u3057\u306a\u3044\n    if (result == null) return;\n\n    \/\/ \u7d50\u679c\u3092state\u306b\u53cd\u6620\u3057\u3066\u753b\u9762\u306b\u53cd\u6620\n    setState(() {\n      _studyTime = result[&#039;studyTime&#039;];\n      _playTime = result[&#039;playTime&#039;];\n      _differenceTime = DateTime.utc(0, 0, 0).add(_studyTime.difference(_playTime));\n    });\n  },\n),<\/code><\/pre>\n<ul>\n<li><code>MaterialPageRoute<\/code>\u306e\u5f15\u6570<code>maintainState<\/code>\u306e\u30c7\u30d5\u30a9\u30eb\u30c8\u5024\u304c<code>true<\/code>\u306a\u306e\u3067\u3001\u9077\u79fb\u5143\u753b\u9762\u306f\u7834\u68c4\u3055\u308c\u305a\u306b\u30e1\u30e2\u30ea\u306b\u30ad\u30fc\u30d7\u3055\u308c\u308b\u3089\u3057\u3044<br \/>\n<blockquote>\n<p>Whether the route should remain in memory when it is inactive.<br \/>\nIf this is true, then the route is maintained, so that any futures it is holding from the next route will properly resolve when the next route pops. If this is not necessary, this can be set to false to allow the framework to entirely discard the route's widget hierarchy when it is not visible.<\/p>\n<\/blockquote>\n<\/li>\n<li><code>EditPage<\/code>\u306e\u30a4\u30cb\u30b7\u30e3\u30e9\u30a4\u30b6\u306b\u5fc5\u8981\u306a\u30d1\u30e9\u30e1\u30fc\u30bf\uff08<code>_studyTime<\/code>\u30fb<code>_playTime<\/code>\uff09\u3092\u6e21\u3057\u3066\u3044\u308b<\/li>\n<li>\u9077\u79fb\u5148\u753b\u9762\u304b\u3089<code>Navigator.pup()<\/code>\u3067\u623b\u3063\u305f\u969b\u306e\u51e6\u7406\u7d50\u679c\u3092\u3001<code>async-await<\/code>\u3067\u540c\u671f\u7684\u306b\u53d7\u3051\u53d6\u3063\u3066\u3044\u308b\n<ul>\n<li>\u3053\u306e\u5b9f\u88c5\u3067\u306f\u3001\u51e6\u7406\u7d50\u679c\u3092Map\u3067\u8fd4\u3057\u3066\u3044\u308b<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>\u9077\u79fb\u5148\u753b\u9762\u5074\u306e\u5b9f\u88c5\u306f\u4ee5\u4e0b\u306e\u901a\u308a\u3067\u3059\u3002<br \/>\n&lt;\u30a4\u30cb\u30b7\u30e3\u30e9\u30a4\u30b6&gt;<\/p>\n<pre><code class=\"language-dart\">class EditPage extends StatefulWidget {\n  final DateTime studyTime;\n  final DateTime playTime;\n  EditPage(this.studyTime, this.playTime);\n}<\/code><\/pre>\n<p>&lt;\u9077\u79fb\u5143\u753b\u9762\u306b\u623b\u308b&gt;<\/p>\n<pre><code class=\"language-dart\">child: ElevatedButton(\n  child: Text(&#039;Save&#039;),\n  onPressed: () =&gt; {\n    Navigator.pop(context, {&#039;studyTime&#039;: _studyTime, &#039;playTime&#039;: _playTime}) \/\/ \u51e6\u7406\u7d50\u679c\u3092\u6307\u5b9a\n  },\n),<\/code><\/pre>\n<ul>\n<li><code>Navigator.pup()<\/code>\u306e\u7b2c\u4e8c\u5f15\u6570\u306b\u51e6\u7406\u7d50\u679c\u3092\u6307\u5b9a\u3059\u308b<\/li>\n<\/ul>\n<p>\u30bd\u30fc\u30b9\u30b3\u30fc\u30c9\u5168\u6587\u306f<a href=\"https:\/\/github.com\/rinoguchi\/study_timer\/tree\/without_provider\/lib\">\u3053\u3061\u3089<\/a>\u3092\u53c2\u7167\u304f\u3060\u3055\u3044\u3002<\/p>\n<p>\u4eca\u56de\u306f\u3001\u9077\u79fb\u304c\u4e00\u3064\u3060\u3051\u3060\u3057\u53d7\u3051\u6e21\u3059\u30d1\u30e9\u30e1\u30fc\u30bf\u3082\u5c11\u306a\u3044\u306e\u3067\u3053\u308c\u3067\u3044\u3044\u3068\u601d\u3044\u307e\u3059\u304c\u3001\u8907\u6570\u306e\u753b\u9762\uff08Route\uff09\u306b\u8de8\u308b\u9077\u79fb\u3084\u30d1\u30e9\u30e1\u30fc\u30bf\u304c\u591a\u3044\u30b1\u30fc\u30b9\u306f\u3053\u306e\u65b9\u6cd5\u3060\u3068\u9762\u5012\u3060\u3068\u601d\u3044\u307e\u3059\u3002<br \/>\n\u305d\u306e\u3088\u3046\u306a\u5834\u5408\u306f\u3001Provider\u3067\u72b6\u614b\u7ba1\u7406\u3057\u3064\u3064\u3001\u7570\u306a\u308bRoute\u3067\u5171\u6709\u3059\u308b\u6b21\u306b\u7d39\u4ecb\u3059\u308b\u65b9\u6cd5\u304c\u826f\u3055\u305d\u3046\u3067\u3059\u3002<\/p>\n<h2>Provider\u3067\u72b6\u614b\u7ba1\u7406\u3057\u3001\u7570\u306a\u308bRoute\u3067\u5171\u6709\u3059\u308b\u65b9\u6cd5<\/h2>\n<p><a href=\"https:\/\/flutter.dev\/docs\/development\/data-and-backend\/state-mgmt\/simple\">\u3053\u3061\u3089<\/a> \u3067\u7d39\u4ecb\u3055\u308c\u3066\u3044\u308b <a href=\"https:\/\/pub.dev\/packages\/provider\">Provider<\/a> \u306f\u3001\u540c\u4e00Route\u5185\u306e Widget \u9593\u3067\u72b6\u614b\u3092\u5171\u6709\u3059\u308b\u305f\u3081\u306e\u65b9\u6cd5\u306a\u306e\u3067\u3059\u304c\u3001\u7570\u306a\u308b Route \u3092\u4f5c\u6210\u3059\u308b\u969b\u306b\u3001\u65e2\u5b58\u306e\u30e2\u30c7\u30eb\u30af\u30e9\u30b9\u3092\u6e21\u3059\u3053\u3068\u304c\u3067\u304d\u308b\u306e\u3067\u3001\u7570\u306a\u308b Route \u3067\u3082\u5171\u6709\u3067\u304d\u308b\u3088\u3046\u3067\u3059\u3002<\/p>\n<h3>Provider \u3067\u72b6\u614b\u7ba1\u7406\u3059\u308b<\/h3>\n<p>\u3053\u308c\u307e\u3067<code>StatelessWidget<\/code>\u3067\u72b6\u614b\u7ba1\u7406\u3057\u3066\u3044\u305f\u306e\u3067\u3001Provider \u3067\u72b6\u614b\u7ba1\u7406\u3059\u308b\u3088\u3046\u306b\u5909\u66f4\u3057\u3066\u3044\u304d\u307e\u3059\u3002<br \/>\n\u203b \u30bd\u30fc\u30b9\u30b3\u30fc\u30c9\u306f\u629c\u7c8b\u3067\u3059\u306e\u3067\u3001\u5168\u6587\u3092\u307f\u305f\u3044\u5834\u5408\u306f <a href=\"https:\/\/github.com\/rinoguchi\/study_timer\/blob\/0238aa987e11e17e48ee7673a529ffe6d9d796cd\/lib\/main.dart\">\u3053\u3061\u3089<\/a> \u3068 <a href=\"https:\/\/github.com\/rinoguchi\/study_timer\/blob\/0238aa987e11e17e48ee7673a529ffe6d9d796cd\/lib\/timeKeeper.dart\">\u3053\u3061\u3089<\/a> \u3092\u53c2\u7167\u304f\u3060\u3055\u3044\u3002<\/p>\n<p>\u307e\u305a\u306f\u3001 pubspec.yaml \u306b\u4f9d\u5b58\u95a2\u4fc2\u3092\u8ffd\u8a18\u3057\u3066\u3001Provider \u3092\u30a4\u30f3\u30b9\u30c8\u30fc\u30eb\u3057\u307e\u3059\u3002<\/p>\n<pre><code class=\"language-yaml\">dependencies:\n  provider: ^5.0.0<\/code><\/pre>\n<p>\u6b21\u306b\u3001\u72b6\u614b\u7ba1\u7406\u7528\u306b<code>ChangeNotifier<\/code>\u3092\u7d99\u627f\u3057\u305f\u30e2\u30c7\u30eb\u30af\u30e9\u30b9\u3092\u4f5c\u308a\u307e\u3059\u3002<\/p>\n<ul>\n<li>\u30d7\u30ed\u30d1\u30c6\u30a3\u306f\u30d7\u30e9\u30a4\u30d9\u30fc\u30c8\u306b\u3057\u3066\u304a\u304d\u3001getter\/setter \u3092\u7d4c\u7531\u3057\u3066\u30a2\u30af\u30bb\u30b9\u3059\u308b<\/li>\n<li>setter \u3067\u5024\u304c\u5909\u66f4\u3055\u308c\u305f\u6642\u306b <code>notifyListeners()<\/code> \u3092\u547c\u3073\u51fa\u3057\u3001\u5909\u66f4\u3092 Provider \u306b\u4f1d\u3048\u308b<\/li>\n<\/ul>\n<pre><code class=\"language-dart\">class TimeKeeper extends ChangeNotifier {\n  DateTime _studyTime = DateTime.utc(0, 0, 0);\n  DateTime _playTime = DateTime.utc(0, 0, 0);\n\n  DateTime get studyTime =&gt; _studyTime;\n  set studyTime(DateTime datetime) {\n    _studyTime = datetime;\n    notifyListeners();\n  }\n\n  DateTime get playTime =&gt; _playTime;\n  set playTime(DateTime datetime) {\n    _playTime = datetime;\n    notifyListeners();\n  }\n}<\/code><\/pre>\n<p>\u6b21\u306b\u3001Provider\u3092\u4f7f\u3063\u305f\u30da\u30fc\u30b8\u3092\u4f5c\u308a\u307e\u3059\u3002<\/p>\n<ul>\n<li><code>MaterialApp<\/code>\u306e<code>home<\/code>\u306b Widget \u306e\u4ee3\u308f\u308a\u306b\u3001<code>ChangeNotifierProvider<\/code> \u3092\u6307\u5b9a\u3059\u308b<\/li>\n<li><code>create<\/code>\u306b\u3001<code>ChangeNotifier<\/code>\u3092\u7d99\u627f\u3057\u305f\u30e2\u30c7\u30eb\u30af\u30e9\u30b9\u3092\u521d\u671f\u5316\u3059\u308b\u95a2\u6570\u3092\u6307\u5b9a\u3066\u3044\u308b<\/li>\n<li><code>StatelessWidget<\/code>\u306e<code>build()<\/code>\u5185\u306e<code>TimeKeeper timeKeeper = context.watch&lt;TimeKeeper&gt;();<\/code>\u3067Provider\u3067\u7ba1\u7406\u3057\u3066\u3044\u308b\u30e2\u30c7\u30eb\u3092\u3001\u5909\u66f4\u3092\u76e3\u8996\u3059\u308b\u5f62\u3067\u53d6\u5f97\u3057\u3066\u3044\u308b\n<ul>\n<li>\u3053\u306e\u53d6\u5f97\u65b9\u6cd5\u3060\u3068\u3001\u30e2\u30c7\u30eb\u306e\u4e2d\u8eab\u304c\u5909\u66f4\u3055\u308c\u305f\u969b\u306b UI \u304c rebuild \u3055\u308c\u308b<\/li>\n<li>\u76e3\u8996\u304c\u4e0d\u8981\u306a\u5834\u5408\u306f\u3001<code>context.read()<\/code>\u3067\u53d6\u5f97\u3059\u308b<\/li>\n<li><code>build()<\/code> \u4ee5\u5916\u3067\u30a2\u30af\u30bb\u30b9\u3057\u305f\u3044\u5834\u5408\u306f\u3001<code>Provider.of<\/code>\u3092\u5229\u7528\u3059\u308b<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<pre><code class=\"language-dart\">void main() async {\n  runApp(\n    MaterialApp(\n        home: ChangeNotifierProvider( \/\/ Widget \u3067\u306f\u306a\u304f\u3001ChangeNotifierProvider\u3092\u6307\u5b9a\n          create: (context) =&gt; TimeKeeper(), \/\/ ChangeNotifier \u3092\u7d99\u627f\u3057\u305f\u30e2\u30c7\u30eb\u30af\u30e9\u30b9\n          child: TimerPage(),\n        )));\n}\n\n\/\/\/ \u30bf\u30a4\u30de\u30fc\u30da\u30fc\u30b8\nclass TimerPage extends StatelessWidget {\n  @override\n  Widget build(BuildContext context) {\n    TimeKeeper timeKeeper = context.watch&lt;TimeKeeper&gt;(); \/\/ \u30e2\u30c7\u30eb\u30af\u30e9\u30b9\u3092\u53d6\u5f97\n    return Column(\n      children: &lt;Widget&gt;[\n        Text(timeKeeper.studyTime), \/\/ \u30e2\u30c7\u30eb\u30af\u30e9\u30b9\u306bgetter\u3092\u901a\u3058\u3066\u30a2\u30af\u30bb\u30b9\n        Text(timeKeeper.playTime),  \/\/ \u540c\u4e0a\n      ])\n  );\n}<\/code><\/pre>\n<h3>\u753b\u9762\u9077\u79fb\u6642\u306b Provider \u3092\u6e21\u3059<\/h3>\n<p>\u30dc\u30bf\u30f3\u3092\u30af\u30ea\u30c3\u30af\u3057\u3066\u3001\u753b\u9762\u9077\u79fb\u3092\u884c\u3046\u51e6\u7406\u3092\u8a18\u8f09\u3057\u307e\u3059\u3002<\/p>\n<ul>\n<li><code>ChangeNotifierProvider.value()<\/code>\u3092\u4f7f\u3063\u3066\u3001\u65e2\u5b58\u306e\u30e2\u30c7\u30eb\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u6307\u5b9a\u3057\u3066\u3001Provider \u3092\u4f5c\u6210\u3059\u308b\n<ul>\n<li>\u3053\u308c\u306b\u3088\u308a\u5225Route\u3067\u3082\u72b6\u614b\uff08\u30e2\u30c7\u30eb\uff09\u3092\u5171\u6709\u3067\u304d\u308b<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<pre><code class=\"language-dart\">Widget build(BuildContext context) {\n  TimeKeeper timeKeeper = context.watch&lt;TimeKeeper&gt;();\n\n  \/\/ \u3044\u308d\u3044\u308d\u7701\u7565\n\n  TextButton(\n    child: Text(&#039;edit&#039;),\n    onPressed: () {\n      Navigator.push(\n        context,\n        MaterialPageRoute(\n          builder: (context) =&gt; ChangeNotifierProvider.value(\n            value: timeKeeper, \/\/ \u65e2\u5b58\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u6307\u5b9a\n            child: EditPage(),\n          )),\n      );\n    }\n  )\n)<\/code><\/pre>\n<p>\u6700\u5f8c\u306b\u9077\u79fb\u5148\u753b\u9762\uff08\u7de8\u96c6\u753b\u9762\uff09\u3092\u5b9f\u88c5\u3057\u307e\u3057\u305f\u3002<br \/>\n\u4eca\u56de\u306f\u3001\u753b\u9762\u5185\u3067\u7de8\u96c6\u3057\u3066\u6700\u7d42\u7684\u306b Save \u30dc\u30bf\u30f3\u3092\u30af\u30ea\u30c3\u30af\u3057\u305f\u3089\u53cd\u6620\u3059\u308b\u4ed5\u7d44\u307f\u306a\u306e\u3067\u3001<code>StatefulWidget<\/code>\u3092\u4f7f\u3063\u3066\u5b9f\u88c5\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n<ul>\n<li>Provider\u7ba1\u7406\u306e\u30e2\u30c7\u30eb\u3092\u5143\u306b\u3001\u30ed\u30fc\u30ab\u30eb\u5909\u6570\u3092\u521d\u671f\u5316\u3059\u308b\u51e6\u7406\u306f <code>didChangeDependencies<\/code>\u306b\u3066\u884c\u3046\n<ul>\n<li><code>StatelessWidget<\/code>\u3092\u4f7f\u3046\u5834\u5408\u306f\u3001<code>build()<\/code>\u306e\u6700\u521d\u3067\u521d\u671f\u5316\u51e6\u7406\u3092\u884c\u3048\u3070OK\u3067\u3059<\/li>\n<\/ul>\n<\/li>\n<li><code>build()<\/code>\u3067 Widget\u30c4\u30ea\u30fc\u3092\u69cb\u7bc9\u3059\u308b\u969b\u306b\u3001<code>context.watch&lt;TimeKeeper&gt;()<\/code>\u3067 Provider \u304b\u3089\u30e2\u30c7\u30eb\u30af\u30e9\u30b9\u3092\u3001\u76e3\u8996\u3059\u308b\u5f62\u3067\u53d6\u5f97\u3057\u3066\u304a\u304f<\/li>\n<li><code>Save<\/code> \u30dc\u30bf\u30f3\u3092\u30bf\u30c3\u30d7\u3057\u305f\u969b\u306b\u3001\u30e2\u30c7\u30eb\u30af\u30e9\u30b9\u306e setter \u3092\u547c\u3073\u51fa\u3057\uff08<code> timeKeeper.studyTime = _studyTime<\/code>\uff09\u3066\u3001\u30e2\u30c7\u30eb\u306b\u53cd\u6620\u3057\u3066\u3044\u308b<\/li>\n<li>setter \u5185\u3067 <code>notifyListeners()<\/code> \u3057\u3066\u308b\u306e\u3067\u3001\u3053\u306e\u30e2\u30c7\u30eb\u3092 Listen \u3057\u3066\u3044\u308b Widget \u306b\u5909\u66f4\u304c\u901a\u77e5\u3055\u308c\u308b<\/li>\n<\/ul>\n<pre><code class=\"language-dart\">class EditPage extends StatefulWidget {\n  @override\n  _EditPageState createState() =&gt; _EditPageState();\n}\n\nclass _EditPageState extends State&lt;EditPage&gt; {\n  DateTime _studyTime; \/\/ \u3053\u306e\u30da\u30fc\u30b8\u5185\u3067\u7ba1\u7406\u3059\u308b\u72b6\u614b\n  DateTime _playTime; \/\/ \u540c\u4e0a\n\n  @override\n  void didChangeDependencies() {\n    TimeKeeper timeKeeper = context.read&lt;TimeKeeper&gt;(); \/\/ \u3053\u3053\u3067context\u304c\u5fc5\u8981\u3002\u53c2\u7167\u3060\u3051\u306a\u306e\u3067`read`\u3092\u5229\u7528\n    _studyTime = timeKeeper.studyTime;\n    _playTime = timeKeeper.playTime;\n    super.didChangeDependencies();\n  }\n\n  @override\n  Widget build(BuildContext context) {\n    TimeKeeper timeKeeper = context.watch&lt;TimeKeeper&gt;();\n\n    \/\/ \u3044\u308d\u3044\u308d\u7701\u7565\n\n    child: ElevatedButton(\n      child: Text(&#039;Save&#039;),\n      onPressed: () {\n        timeKeeper.studyTime = _studyTime; \/\/ \u3053\u3053\u3067Provider\u3067\u7ba1\u7406\u3059\u308b\u30e2\u30c7\u30eb\u306b\u53cd\u6620\n        timeKeeper.playTime = _playTime;\n        Navigator.pop(context); \/\/ \u5143\u753b\u9762\u306b\u623b\u308b\uff08\u51e6\u7406\u7d50\u679c\u306f\u8fd4\u3055\u306a\u3044\uff09\n      },\n    )\n}<\/code><\/pre>\n<p>\u5c11\u3057\u5927\u5909\u3067\u3057\u305f\u304c\u3001Provider \u3092\u5229\u7528\u3057\u3066\u3044\u3066\u3082\u3001\u7570\u306a\u308b Route \u3067\u72b6\u614b\u3092\u5171\u6709\u3059\u308b\u3053\u3068\u306f\u554f\u984c\u306a\u304f\u3067\u304d\u307e\u3057\u305f\u3002<br \/>\nProvider \u81ea\u4f53\u3082\u3001\u5c0e\u5165\u3059\u308b\u3053\u3068\u3067\u753b\u9762\u3068\u30ed\u30b8\u30c3\u30af\u304c\u5f37\u5236\u7684\u306b\u5206\u96e2\u3055\u308c\u3066\u3001\u30b3\u30fc\u30c9\u306e\u898b\u901a\u3057\u304c\u826f\u304f\u306a\u3063\u305f\u6c17\u304c\u3059\u308b\u306e\u3067\u3088\u304b\u3063\u305f\u3067\u3059\u3002<\/p>\n<h2>\u53c2\u8003: Provider \u3068 WidgetsBindingObserver \u3068\u4f75\u7528\u3059\u308b<\/h2>\n<p>\u4eca\u56de\u306e\u8a18\u4e8b\u3068\u76f4\u63a5\u95a2\u4fc2\u306a\u3044\u3067\u3059\u304c\u3001 pause - resume \u3057\u305f\u969b\u306e\u51e6\u7406\u3092<code>WidgetsBindingObserver<\/code>\u3092\u4f7f\u3063\u3066\u57cb\u3081\u8fbc\u3093\u3067\u3044\u305f\u306e\u3067\u3059\u304c\u3001Provider \u3068\u4f75\u7528\u3059\u308b\u969b\u306b\u5c11\u3057\u5de5\u592b\u304c\u5fc5\u8981\u3067\u3057\u305f\u3002<\/p>\n<p>\u3068\u3044\u3046\u306e\u3082\u3001<code>StatelessWidget<\/code>\u3067\u306f<code>didChangeAppLifecycleState()<\/code>\u306e\u30bf\u30a4\u30df\u30f3\u30b0\u3067<code>context<\/code>\u306b\u30a2\u30af\u30bb\u30b9\u3067\u304d\u305a\u3001\u7d50\u679c\u3068\u3057\u3066 Provider \u3067\u7ba1\u7406\u3057\u3066\u3044\u308b\u30e2\u30c7\u30eb\u306b\u30a2\u30af\u30bb\u30b9\u3067\u304d\u306a\u3044\u305f\u3081\u3067\u3059\u3002<\/p>\n<p>\u3057\u3087\u3046\u304c\u306a\u3044\u306e\u3067\u3001<code>StatefullWidget<\/code> \u3068 Provider \u3092\u5171\u5b58\u3055\u305b\u308b\u5f62\u306b\u3057\u307e\u3057\u305f\u3002<\/p>\n<ul>\n<li>State\u30af\u30e9\u30b9\u3067<code>WidgetsBindingObserver<\/code>\u3092 mix-in \u3059\u308b<\/li>\n<li><code>initState()<\/code>\u3067<code>WidgetsBinding.instance.addObserver(this)<\/code>\u3092\u3001<code>dispose()<\/code>\u3067<code>WidgetsBinding.instance.removeObserver(this)<\/code>\u3092\u5b9f\u884c\u3059\u308b<\/li>\n<li><code>didChangeAppLifecycleState()<\/code>\u3067 Provider \u304b\u3089\u30e2\u30c7\u30eb\u3092\u53d6\u5f97\u3059\u308b<\/li>\n<\/ul>\n<pre><code class=\"language-dart\">class TimerApp extends StatelessWidget {\n  @override\n  Widget build(BuildContext context) {\n    return MaterialApp(\n        title: &#039;Study Timer&#039;,\n        home: ChangeNotifierProvider(\n          create: (context) =&gt; TimeKeeper(),\n          child: TimerPage(),\n        ));\n  }\n}\n\n\/\/\/ \u30bf\u30a4\u30de\u30fc\u30da\u30fc\u30b8\nclass TimerPage extends StatefulWidget {\n  @override\n  _TimerPageState createState() =&gt; _TimerPageState();\n}\n\nclass _TimerPageState extends State&lt;TimerPage&gt; with WidgetsBindingObserver {\n  @override\n  void initState() {\n    super.initState();\n    WidgetsBinding.instance.addObserver(this);\n  }\n\n  @override\n  void dispose() {\n    WidgetsBinding.instance.removeObserver(this);\n    super.dispose();\n  }\n\n  @override\n  void didChangeAppLifecycleState(AppLifecycleState state) {\n    TimeKeeper timeKeeper = context.read&lt;TimeKeeper&gt;(); \/\/ \u3053\u3053\u3067Provider\u304b\u3089\u30e2\u30c7\u30eb\u3092\u53d6\u5f97\n    if (state == AppLifecycleState.paused) {\n      timeKeeper.handleOnPaused();\n    } else if (state == AppLifecycleState.resumed) {\n      timeKeeper.handleOnResumed();\n    }\n  }\n\n  @override\n  Widget build(BuildContext context) {\n    TimeKeeper timeKeeper = context.watch&lt;TimeKeeper&gt;();\n    return Scaffold(\n      \/\/ \u7701\u7565\n    )\n  }\n}<\/code><\/pre>\n<h2>\u3055\u3044\u3054\u306b<\/h2>\n<p>\u4eca\u56de\u3001\u7570\u306a\u308b\u753b\u9762\uff08Route\uff09\u3067\u72b6\u614b\u3092\u5171\u6709\u3059\u308b\u3068\u3053\u308d\u306b\u30d5\u30a9\u30fc\u30ab\u30b9\u3057\u3066\u8abf\u67fb\u3057\u307e\u3057\u305f\u304c\u3001\u7d50\u5c40\u3001\u72b6\u614b\u7ba1\u7406\u3068\u3057\u3066\u3001<code>StatefullWidget<\/code>\u3068<code>Provider<\/code>\u3069\u3063\u3061\u304c\u3044\u3044\u304b\uff1f\u3068\u3044\u3046\u3053\u3068\u306a\u6c17\u304c\u3057\u307e\u3057\u305f\u3002<br \/>\n\u305d\u3046\u3044\u3046\u610f\u5473\u3067\u306f\u3001\u7d50\u5c40\u8907\u96d1\u306b\u306a\u3063\u3066\u304d\u305f\u3089\u3001<code>Provider<\/code>\u3067\u7ba1\u7406\u3057\u305f\u304f\u306a\u308b\u3053\u3068\u3092\u8003\u3048\u308b\u3068\u3001\u6700\u521d\u304b\u3089<code>Provider<\/code>\u3067\u5b9f\u88c5\u3057\u3066\u304a\u304f\u306e\u304c\u826f\u3055\u305d\u3046\u3060\u306a\u3001\u3001\u3068\u3044\u3046\u306e\u304c\u6240\u611f\u3067\u3059\u3002<\/p>\n<p>\u3061\u306a\u307f\u306b\u3001\u72b6\u614b\u7ba1\u7406\u306b\u3064\u3044\u3066\u306f\u3001Provider \u3092\u9032\u5316\u3055\u305b\u305f\u3088\u3046\u306a <a href=\"https:\/\/pub.dev\/packages\/riverpod\">Riverpod<\/a> \u3068\u3044\u3046\u30d1\u30c3\u30b1\u30fc\u30b8\u304c\u3042\u308b\u306e\u3067\u3001\u6b63\u5f0f\u7248\u304c\u30ea\u30ea\u30fc\u30b9\u3055\u308c\u305f\u3089\u8a66\u3057\u3066\u307f\u305f\u3044\u3068\u601d\u3044\u307e\u3059\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Flutter \u3067\u304a\u52c9\u5f37\u6642\u9593\u7ba1\u7406\u7528\u306e\u30bf\u30a4\u30de\u30fc\u30a2\u30d7\u30ea\u3092\u4f5c\u3063\u3066\u3044\u308b\u306e\u3067\u3059\u304c\u3001\u983b\u7e41\u306b\u30bf\u30a4\u30de\u30fc\u306e\u8d77\u52d5\uff0f\u505c\u6b62\u3057\u5fd8\u308c\u304c\u767a\u751f\u3059\u308b\u306e\u3067\u3001\u624b\u4f5c\u696d\u3067\u7d4c\u904e\u6642\u9593\u3092\u7de8\u96c6\u3067\u304d\u308b\u3088\u3046\u306b\u3057\u307e\u3057\u305f\u3002 \u4ee5\u4e0b\u306e\u3088\u3046\u306b\u5225\u753b\u9762\u3067\u7de8\u96c6\u3059\u308b\u4f5c\u308a\u306a\u306e\u3067\u3059\u304c\u3001\u5225\u753b\u9762\uff08route\uff09\u3067\u4e0a\u624b\u304f\u5024\u3092\u3084\u308a\u53d6\u308a\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u3001\u305d\u306e\u5b9f\u88c5\u65b9\u6cd5\u3092\u4e8c\u3064\u307b\u3069\u8a66\u3057\u305f\u306e\u3067\u7d39\u4ecb\u3057\u307e\u3059\u3002 StatefullWidget + \u753b\u9762\u9077\u79fb\u6642\u306b\u30d1\u30e9\u30e1\u30fc\u30bf\u6e21\u3057\u3059\u308b\u65b9\u6cd5 \u4e00\u3064\u76ee\u306e\u65b9\u6cd5\u306f\u3001StatefullWidget\u3067\u9077\u79fb\u5143\u753b\u9762\uff08route\uff09\u306e\u72b6\u614b\uff08state\uff09\u3092\u7ba1\u7406\u3057\u3064\u3064\u3001\u5225\u753b\u9762\u306b\u9077\u79fb\u3059\u308b\u969b\u306b\u30d1\u30e9\u30e1\u30fc\u30bf\u3092\u6e21\u3059\u65b9\u6cd5\u3067\u3059\u3002\u3053\u306e\u65b9\u6cd5\u3060\u3068\u9077\u79fb\u5143\u753b\u9762\u306e\u72b6\u614b\uff08state\uff09\u304c\u753b\u9762\u9077\u79fb\u6642\u306b\u7834\u68c4\u3055\u308c\u308b\u3082\u306e\u3060\u3068\u601d\u3063\u3066\u3044\u305f\u306e\u3067\u3059\u304c\u3001maintainState=true\u306e\u8a2d\u5b9a\u3067\u3042\u308c\u3070\u7834\u68c4\u3055\u308c\u306a\u3044\u3088\u3046\u306a\u306e\u3067\u3001\u7d50\u69cb\u4f7f\u3044\u52dd\u624b\u304c\u826f\u3055\u305d\u3046\u3067\u3059\u3002 \u753b\u9762\u9077\u79fb\u306e\u5b9f\u88c5\u306f\u3001Flutter cookbook \u306e Navig <a href=\"http:\/\/localhost:8000\/2021\/05\/share-state-between-other-routes.html\" class=\"read-more button-fancy -red\"><span class=\"btn-arrow\"><\/span><span class=\"twp-read-more text\">Continue Reading<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[38],"tags":[],"_links":{"self":[{"href":"http:\/\/localhost:8000\/wp-json\/wp\/v2\/posts\/610"}],"collection":[{"href":"http:\/\/localhost:8000\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/localhost:8000\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/localhost:8000\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/localhost:8000\/wp-json\/wp\/v2\/comments?post=610"}],"version-history":[{"count":0,"href":"http:\/\/localhost:8000\/wp-json\/wp\/v2\/posts\/610\/revisions"}],"wp:attachment":[{"href":"http:\/\/localhost:8000\/wp-json\/wp\/v2\/media?parent=610"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/localhost:8000\/wp-json\/wp\/v2\/categories?post=610"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/localhost:8000\/wp-json\/wp\/v2\/tags?post=610"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}