How to remove these lines between Row children - windows

Question

I'm new to flutter, and I'm trying to divide the screen into three parts, here's my attempt:
class Homepage extends Statelesswidget {
const HomePage({Key? key}): super (key: key);
#override
Widget build(BuildContext context) {
return Row(children: [
const Expanded(
flex: 1,
child: Scaffold(
body: Center(child: Text("Left")),
), // Scaffold
), // Expanded
Expanded(
flex: 2,
child: Scaffold(
appBar: AppBar(),
body: const Center(child: Text("Middle")),
), // Scaffold
), // Expanded
const Expanded(
flex: 1,
child: Scaffold(
body: Center(child: Text("Right")),
), // Scaffold
) // Expanded
]);
}
}
and main.dart looks like:
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return const MaterialApp(
home: HomePage(),
debugShowCheckedModeBanner: false,
);
}
}
Here's the result:
I got these vertical lines out of nowhere, how can I get rid of them?

Answer 1

Welcome to Flutter 💙
These lines are the boarders of the Scaffold widget which you are using inside each Expanded widget in the row.
Now intead of looking for a way to remove these border lines, I suggest you to learn more about the Scaffold widget in Flutter
Since you are new to Flutter, you have to be aware with the goal of using Scaffold widget, which is stated in the official docs as the following:
Implements the basic material design visual layout structure.
This class provides APIs for showing drawers and bottom sheets.
So in other words, we use the Scaffold Widget as a basic canvas for the screen with some properties to implement popular layout designs, such as AppBar, BottomNavigationBar, FloatingActionButton, etc...
Then, we use it once in the screen to set the basic layout, and does not required to be used multiple times for each sub part of the screen
Then your HomePage code should be something like:
class HomePage extends StatelessWidget {
const HomePage({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return Scaffold(
body: Row(children: [
const Expanded(
flex: 1,
child: Center(child: Text("Left")),
), // Expanded
Expanded(
flex: 2,
child: Column(
children: [
AppBar(),
const Expanded(
child: Center(child: Text("Middle")),
),
],
),
),
const Expanded(
flex: 1,
child: Center(child: Text("Right")),
)
]),
);
}
}