ExpansionTile within an IconButton in AppBar flutter - flutter

Question

I'm trying to build a collapse view after clicking an IconButton on my AppBar widget, I used ExpansionTile but nothing happens after I clicked the IconButton.
appBar: AppBar(
actions: <Widget>[
IconButton(
onPressed: () {
ExpansionTile(
title: Text(
"Settings",
style: TextStyle(
fontSize: 18.0,
fontWeight: FontWeight.bold
),
),
);
},
icon: Icon(Icons.settings),
),
],
),
Did I write the code right, or should I consider refactoring it. Thanks in advance!

Answer 1

Yes, you need to refactor your code because you cannot insert a widget into the widget tree this way directly from a function. I'm not sure of what you are trying to do, so I made two assumptions (1) You are trying to show a Expansion Tile in the app bar or (2) You want to show a Popup menu. Please see my code below to understand how you can achieve both.
import 'package:flutter/material.dart';
final Color darkBlue = const Color.fromARGB(255, 18, 32, 47);
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
theme: ThemeData.dark().copyWith(scaffoldBackgroundColor: darkBlue),
title: 'Welcome to Flutter',
debugShowCheckedModeBanner: false,
home: HomePage(),
);
}
}
class HomePage extends StatefulWidget {
#override
_HomePageState createState() => _HomePageState();
}
class _HomePageState extends State<HomePage> {
Widget myWidget = Container(
child: const Text("Flutter"),
);
String myText = 'Hello, World!';
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(title: myWidget, actions: [
IconButton(
onPressed: () async {
print(context);
showMenu(
context: context,
position: const RelativeRect.fromLTRB(110.0, 80.0, 0.0, 0.0),
items: ["One", "Two", "Three", "Four"]
.map(
(value) => PopupMenuItem<String>(
child: Text(value),
value: value,
),
)
.toList(),
elevation: 8.0,
);
},
icon: Icon(Icons.settings),
),
PopupMenuButton<int>(
onSelected: (selected) {
setState(
() {
myText = "You selected the menu number $selected";
},
);
},
itemBuilder: (BuildContext context) => <PopupMenuEntry<int>>[
const PopupMenuItem<int>(
value: 1,
child: Text('First Item'),
),
const PopupMenuItem<int>(
value: 2,
child: Text('Second Item'),
),
const PopupMenuItem<int>(
value: 3,
child: Text('Thrid Item'),
),
const PopupMenuItem<int>(
value: 4,
child: Text('Fourth Item'),
),
],
)
]),
body: Center(
child: Text(myText, style: Theme.of(context).textTheme.headline4),
),
);
}
}