{"id":28,"date":"2025-06-13T21:53:44","date_gmt":"2025-06-13T13:53:44","guid":{"rendered":"https:\/\/www.bqmz001.top\/?p=28"},"modified":"2025-06-13T21:53:44","modified_gmt":"2025-06-13T13:53:44","slug":"flutter-provider-%e6%9c%80%e7%ae%80%e5%8d%95demo","status":"publish","type":"post","link":"https:\/\/www.bqmz001.top\/index.php\/2025\/06\/13\/flutter-provider-%e6%9c%80%e7%ae%80%e5%8d%95demo\/","title":{"rendered":"flutter provider \u6700\u7b80\u5355demo"},"content":{"rendered":"<h1>Flutter CounterProvider \u72b6\u6001\u7ba1\u7406\u7c7b<\/h1>\n<p>\u6b64\u6587\u4ef6\u5b9a\u4e49\u4e86\u4e00\u4e2a\u4f7f\u7528 <code>Provider<\/code> \u5e93\u8fdb\u884c\u72b6\u6001\u7ba1\u7406\u7684 <code>CounterProvider<\/code> \u7c7b\uff0c\u7528\u4e8e\u7ba1\u7406\u8ba1\u6570\u5668\u72b6\u6001\u3002<\/p>\n<h2>\u4ee3\u7801\u5185\u5bb9<\/h2>\n<h3>count_provider.dart<\/h3>\n<pre><code>import &#039;package:flutter\/foundation.dart&#039;;\n\nclass CounterProvider with ChangeNotifier {\n  int _counter = 0;\n\n  int get counter =&gt; _counter;\n\n  void increment() {\n    _counter++;\n    notifyListeners(); \/\/ \u901a\u77e5\u6240\u6709\u76d1\u542c\u8005\u72b6\u6001\u5df2\u6539\u53d8\n  }\n}\n<\/code><\/pre>\n<h3>main.dart<\/h3>\n<pre><code>import &#039;package:flutter\/material.dart&#039;;\nimport &#039;package:provider\/provider.dart&#039;;\nimport &#039;counter_provider.dart&#039;;\n\nvoid main() {\n  runApp(\n    ChangeNotifierProvider(\n      create: (context) =&gt; CounterProvider(),\n      child: const MyApp(),\n    ),\n  );\n}\n\nclass MyApp extends StatelessWidget {\n  const MyApp({super.key});\n\n  @override\n  Widget build(BuildContext context) {\n    return MaterialApp(\n      title: &#039;Flutter Demo&#039;,\n      theme: ThemeData(\n        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),\n      ),\n      home: const MyHomePage(title: &#039;Flutter Demo Home Page&#039;),\n    );\n  }\n}\n\nclass MyHomePage extends StatelessWidget {\n  const MyHomePage({super.key, required this.title});\n\n  final String title;\n\n  @override\n  Widget build(BuildContext context) {\n    return Scaffold(\n      appBar: AppBar(\n        backgroundColor: Theme.of(context).colorScheme.inversePrimary,\n        title: Text(title),\n      ),\n      body: Center(\n        child: Column(\n          mainAxisAlignment: MainAxisAlignment.center,\n          children: &lt;Widget&gt;[\n            const Text(&#039;You have pushed the button this many times:&#039;),\n            Text(\n              &#039;${Provider.of&lt;CounterProvider&gt;(context).counter}&#039;,\n              style: Theme.of(context).textTheme.headlineMedium,\n            ),\n          ],\n        ),\n      ),\n      floatingActionButton: FloatingActionButton(\n        onPressed: () {\n          Provider.of&lt;CounterProvider&gt;(context, listen: false).increment();\n        },\n        tooltip: &#039;Increment&#039;,\n        child: const Icon(Icons.add),\n      ),\n    );\n  }\n}\n<\/code><\/pre>\n<h1>\u90a3\u8981\u662f\u6709\u591a\u4e2aprovider\u5462\uff1f<\/h1>\n<h3>\u5728\u4e4b\u524d\u6761\u4ef6\u4e0b\u518d\u52a0\u4e00\u4e2atheme_provider.dart<\/h3>\n<pre><code>import &#039;package:flutter\/material.dart&#039;;\nimport &#039;package:flutter\/foundation.dart&#039;;\n\nclass ThemeProvider with ChangeNotifier {\n  bool _isDarkMode = false;\n\n  bool get isDarkMode =&gt; _isDarkMode;\n\n  void toggleTheme() {\n    _isDarkMode = !_isDarkMode;\n    notifyListeners(); \/\/ \u901a\u77e5\u6240\u6709\u76d1\u542c\u8005\u72b6\u6001\u5df2\u6539\u53d8\n  }\n\n  ThemeData get currentTheme {\n    return _isDarkMode\n        ? ThemeData.dark(useMaterial3: true)\n        : ThemeData.light(useMaterial3: true);\n  }\n}\n<\/code><\/pre>\n<h3>main.dart\u6539\u52a8<\/h3>\n<pre><code>import &#039;package:flutter\/material.dart&#039;;\nimport &#039;package:provider\/provider.dart&#039;;\nimport &#039;counter_provider.dart&#039;;\nimport &#039;theme_provider.dart&#039;;\n\nvoid main() {\n  runApp(\n    MultiProvider(\n      providers: [\n        ChangeNotifierProvider(create: (context) =&gt; CounterProvider()),\n        ChangeNotifierProvider(create: (context) =&gt; ThemeProvider()),\n      ],\n      child: const MyApp(),\n    ),\n  );\n}\n\nclass MyApp extends StatelessWidget {\n  const MyApp({super.key});\n\n  @override\n  Widget build(BuildContext context) {\n    final themeProvider = Provider.of&lt;ThemeProvider&gt;(context);\n    return MaterialApp(\n      title: &#039;Flutter Demo&#039;,\n      theme: themeProvider.currentTheme,\n      home: const MyHomePage(title: &#039;Flutter Demo Home Page&#039;),\n    );\n  }\n}\n\nclass MyHomePage extends StatelessWidget {\n  const MyHomePage({super.key, required this.title});\n\n  final String title;\n\n  @override\n  Widget build(BuildContext context) {\n    final counterProvider = Provider.of&lt;CounterProvider&gt;(context);\n    final themeProvider = Provider.of&lt;ThemeProvider&gt;(context);\n\n    return Scaffold(\n      appBar: AppBar(\n        backgroundColor: Theme.of(context).colorScheme.inversePrimary,\n        title: Text(title),\n        actions: [\n          IconButton(\n            icon: Icon(themeProvider.isDarkMode\n                ? Icons.light_mode\n                : Icons.dark_mode),\n            onPressed: () {\n              themeProvider.toggleTheme();\n            },\n          ),\n        ],\n      ),\n      body: Center(\n        child: Column(\n          mainAxisAlignment: MainAxisAlignment.center,\n          children: &lt;Widget&gt;[\n            const Text(&#039;You have pushed the button this many times:&#039;),\n            Text(\n              &#039;${counterProvider.counter}&#039;,\n              style: Theme.of(context).textTheme.headlineMedium,\n            ),\n          ],\n        ),\n      ),\n      floatingActionButton: FloatingActionButton(\n        onPressed: () {\n          counterProvider.increment();\n        },\n        tooltip: &#039;Increment&#039;,\n        child: const Icon(Icons.add),\n      ),\n    );\n  }\n}\n<\/code><\/pre>\n<p><em>\u7b80\u5355demo\u5148\u77e5\u9053\u8fd9\u73a9\u610f\u600e\u4e48\u7528\uff0c\u5982\u679c\u9047\u5230\u540e\u9762\u590d\u6742\u7684\u4e1c\u897f\u53ef\u4ee5\u518d\u53bb\u5b66\u4e60\u539f\u7406<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Flutter CounterProvider \u72b6\u6001\u7ba1\u7406\u7c7b \u6b64\u6587\u4ef6\u5b9a\u4e49\u4e86\u4e00\u4e2a\u4f7f\u7528 Provider \u5e93\u8fdb\u884c\u72b6\u6001 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-28","post","type-post","status-publish","format-standard","hentry","category-androidflutter"],"_links":{"self":[{"href":"https:\/\/www.bqmz001.top\/index.php\/wp-json\/wp\/v2\/posts\/28","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bqmz001.top\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bqmz001.top\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bqmz001.top\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bqmz001.top\/index.php\/wp-json\/wp\/v2\/comments?post=28"}],"version-history":[{"count":6,"href":"https:\/\/www.bqmz001.top\/index.php\/wp-json\/wp\/v2\/posts\/28\/revisions"}],"predecessor-version":[{"id":34,"href":"https:\/\/www.bqmz001.top\/index.php\/wp-json\/wp\/v2\/posts\/28\/revisions\/34"}],"wp:attachment":[{"href":"https:\/\/www.bqmz001.top\/index.php\/wp-json\/wp\/v2\/media?parent=28"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bqmz001.top\/index.php\/wp-json\/wp\/v2\/categories?post=28"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bqmz001.top\/index.php\/wp-json\/wp\/v2\/tags?post=28"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}