flex.dart

import 'package:flutter/material.dart';

void main() {
runApp(
	MaterialApp(
	home: Scaffold(
		appBar: AppBar(
			title: Text('Responsive app '),
			backgroundColor: Colors.greenAccent[400],
			leading: IconButton(
			icon: Icon(Icons.menu),
			onPressed: () {},
			tooltip: 'Menu',
			) //IconButton
			), //AppBar
		body: Center(
		child: Container(
			child: Padding(
			padding: const EdgeInsets.all(14.0),
			child: Column(
			children: <Widget>[
				Row(
				children: <Widget>[
					Flexible(
					flex: 1,
					fit: FlexFit.tight,
					child: Container(
						height: 175,
						decoration: BoxDecoration(
						borderRadius: BorderRadius.circular(10),
						color: Colors.red,
						), //BoxDecoration
					), //Container
					), //Flexible
					SizedBox(
					width: 20,
					), //SizedBox
					Flexible(
					flex: 1,
					fit: FlexFit.loose,
					child: Container(
						height: 175,
						decoration: BoxDecoration(
							borderRadius: BorderRadius.circular(10),
							color: Colors.red,
						) //BoxDecoration
						), //Container
					) //Flexible
				], //<Widget>[]
				mainAxisAlignment: MainAxisAlignment.center,
				), //Row
				Flexible(
				flex: 1,
				fit: FlexFit.loose,
				child: Container(
					width: 380,
					height: 200,
					decoration: BoxDecoration(
						borderRadius: BorderRadius.circular(10),
						color: Colors.blue), //BoxDecoration
				), //Container
				), //Flexible
				Row(
				children: <Widget>[
					Flexible(
					flex: 2,
					fit: FlexFit.tight,
					child: Container(
						width: 180,
						height: 300,
						decoration: BoxDecoration(
						borderRadius: BorderRadius.circular(10),
						color: Colors.cyan,
						), //BoxDecoration
					), //Container
					), //Flexible
					SizedBox(
					width: 20,
					), //SixedBox
					Flexible(
						flex: 2,
						fit: FlexFit.tight,
						child: Container(
							width: 180,
							height: 300,
							decoration: BoxDecoration(
							borderRadius: BorderRadius.circular(10),
							color: Colors.cyan,
							) //BoxDecoration
							) //Conatiner,
						) //Flexible
				], //<widget>[]
				mainAxisAlignment: MainAxisAlignment.center,
				), //Row
			], //<Widget>[]
			mainAxisAlignment: MainAxisAlignment.spaceBetween,
			crossAxisAlignment: CrossAxisAlignment.center,
			), //Column
		) //Padding
			), //Container
		) //Center
		), //Scaffold

	debugShowCheckedModeBanner: false,
)); //MaterialApp
}