Flutter去除右上角Debug标签

问题原因:Flutter右上角显示Debug标签
解决：
1.打release包
2.MaterialApp初始化时，将debugShowCheckedModeBanner设置为false：

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false, // 设置这一属性即可
      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'),
    );
  }
}