問題原因:Flutter右上角顯示Debug標(biāo)簽
解決：
1.打release包
2.MaterialApp初始化時(shí)，將debugShowCheckedModeBanner設(shè)置為false：

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false, // 設(shè)置這一屬性即可
      title: 'Flutter Demo',
      theme: ThemeData(
        // This is the theme of your application.
        //
        // Try running your application with "flutter run". You'll see the
        // application has a blue toolbar. Then, without quitting the app, try
        // changing the primarySwatch below to Colors.green and then invoke
        // "hot reload" (press "r" in the console where you ran "flutter run",
        // or simply save your changes to "hot reload" in a Flutter IDE).
        // Notice that the counter didn't reset back to zero; the application
        // is not restarted.
        primarySwatch: Colors.red,
      ),
      home: MyHomePage(title: 'First Flutter Demo'),
    );
  }
}