First App Using Flutter

First App Using Flutter

In this blog, we are going to create our first mobile app using Flutter.

Note:- No pre-requisite for creating your first app, but recommend having some tools (like vs code or Android Studio) and Flutter installed to create our first very basic app.

Note:- I will be using vs code for developing the app

Let's get started

Step 1:- Let's first generate our app and let's name it my_info_app.

a) To generate the app using command prompt or terminal write the following command in your command prompt and hit enter image.png

Note:- For using Android Studio for creating Flutter apps you should have Flutter and Dart Plugin installed.

b) To generate the app using Android Studio, click on Start a new Flutter Project and the select Flutter application and click next, after that write the name of your app inside Project name and click next, now add your package name and click finish.

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Step 2:- Let's move inside our app folder i.e. my_info_app

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Step 3:- Now let's crack open vs code and let's first see the structure of the app generated by the flutter.

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Note:- For writing our app our main work will be done inside the lib folder shown in the above structure.

Step 4:- Now inside the lib folder, the code you will see is the boilerplate code generated by flutter.

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      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.blue,
        // This makes the visual density adapt to the platform that you run
        // the app on. For desktop platforms, the controls will be smaller and
        // closer together (more dense) than on mobile platforms.
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      // This call to setState tells the Flutter framework that something has
      // changed in this State, which causes it to rerun the build method below
      // so that the display can reflect the updated values. If we changed
      // _counter without calling setState(), then the build method would not be
      // called again, and so nothing would appear to happen.
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return Scaffold(
      appBar: AppBar(
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set our appbar title.
        title: Text(widget.title),
      ),
      body: Center(
        // Center is a layout widget. It takes a single child and positions it
        // in the middle of the parent.
        child: Column(
          // Column is also a layout widget. It takes a list of children and
          // arranges them vertically. By default, it sizes itself to fit its
          // children horizontally, and tries to be as tall as its parent.
          //
          // Invoke "debug painting" (press "p" in the console, choose the
          // "Toggle Debug Paint" action from the Flutter Inspector in Android
          // Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
          // to see the wireframe for each widget.
          //
          // Column has various properties to control how it sizes itself and
          // how it positions its children. Here we use mainAxisAlignment to
          // center the children vertically; the main axis here is the vertical
          // axis because Columns are vertical (the cross axis would be
          // horizontal).
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headline4,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}

Step 5:- Let's Now remove this code and start writing code for our app.

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'My Info App',
      home: MyInfo(),
    );
  }
}

// the code below is used to create a stateless widget to show our basic info
class MyInfo extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold();
  }
}

In the code above we have created a stateless widget named MyInfo that will be used to create the UI which will be shown on our app screen.

Step 6:- Now let's add the image that we will be going to display as our profile image in the app and for doing this we will need to create a folder asset in our root folder and then create another folder named images and in this images folder we will add the image that we will display as our profile image.

Now the folder structure for our app will look like this

Screenshot from 2021-05-22 19-47-00.png

Now since we have added the images folder to the project but there is one more step needed to add the image to your project so that we can display the image in our app and that step is that we need to edit the pubspec.yaml as shown below

Screenshot from 2021-05-22 20-51-49.png

Now since we have added the image to our app so now let's go back to the editor and write the code

Step 7:- Displaying the image that we have added to our project

Screenshot from 2021-05-22 20-57-26.png

Step 8:- Now let us display our name and email address

Screenshot from 2021-05-23 16-34-21.png

Screenshot from 2021-05-23 16-36-45.png

This is it, we have created our first mobile app using the Flutter framework and the Dart programming language.

The code for the above app is available in the following github repository