👇👇 --> Sample App <-- 👇👇

void main() { runApp(const MyApp()); }

class MyApp extends StatelessWidget{ const MyApp({super.key});

@override Widget build(BuildContext context) {

return MaterialApp(  // (ctrl + p) click kore ki ki kora jai dekha jabe
    theme: ThemeData(primarySwatch: Colors.green),
    darkTheme: ThemeData(primarySwatch: Colors.blueGrey),
    color: Colors.indigo,
    debugShowCheckedModeBanner: false,
    home:HomeActivity()    // click -->  ctrl + P

);

} }

class HomeActivity extends StatelessWidget{ const HomeActivity({super.key});

// for code low complexity MySnackBar(message,context){

return ScaffoldMessenger.of(context).showSnackBar(
  SnackBar(content: Text(message))
);

}

@override Widget build(BuildContext context) {

// scaffold er vitore whole screen a ja thakbe tai thakbe
return Scaffold(  //(ctrl + p) use kore ki ki kora jai dekha jabe
  appBar: AppBar(
    title: Text("My Flutter App"),
    //titleSpacing: 90,
    centerTitle: true,
    toolbarHeight: 60,
    toolbarOpacity: 1,
    elevation: 8,
    backgroundColor: Colors.indigo,
    actions: [
      IconButton(onPressed: (){MySnackBar("Iam Search", context);}, icon: Icon(Icons.search)),
      IconButton(onPressed: (){MySnackBar("Iam Comment", context);}, icon: Icon(Icons.comment)),
      IconButton(onPressed: (){MySnackBar("Iam Setting", context);}, icon: Icon(Icons.settings)),
      IconButton(onPressed: (){MySnackBar("Iam Email", context);}, icon: Icon(Icons.email)),
    ],
  ),
  floatingActionButton: FloatingActionButton(
    elevation: 10,
  child: Icon(Icons.add),
  backgroundColor: Colors.indigo,
  onPressed: (){
      MySnackBar("Iam Floating Action Button", context);
  },
),
  bottomNavigationBar: BottomNavigationBar(
    currentIndex: 0,
    items: [
      BottomNavigationBarItem(icon: Icon(Icons.home),label: "Home"),
      BottomNavigationBarItem(icon: Icon(Icons.message),label: "Contact"),
      BottomNavigationBarItem(icon: Icon(Icons.person),label: "Profile"),
    ],
    onTap: (int index){
      if(index==0){
        MySnackBar("Iam Home bottom menu", context);
      }
      if(index==1){
        MySnackBar("Iam contact bottom menu", context);
      }
      if (index==2){
        MySnackBar("Iam Profile bottom menu", context);
      }
    },
  ),


);

} }