Creating Mobile Apps with Flutter

Posted on by Panther

Flutter is a popular mobile application development framework for building high-performance, beautiful, and natively compiled apps for iOS and Android. Flutter provides a rich set of pre-built widgets and an easy-to-use development toolkit that makes building apps fast and easy.

In this tutorial, we will cover everything you need to know to get started with Flutter and build your first mobile app. We will cover setting up your development environment, creating a new Flutter project, building your user interface, adding functionality to your app, and deploying your app to the app store.

Prerequisites

Before we get started, make sure you have the following components:

  • Flutter SDK
  • Android Studio or any other IDE (Integrated Development Environment) of your choice for Flutter.
  • Java Development Kit (JDK)
  • Android SDK Tools
  • An emulator or a physical device that is capable of running Android or iOS.

You can install the Flutter SDK and tools by following the installation guides provided by Google. Flutter is available for Windows, MacOS, and Linux.

Create a New Flutter Project

Once you have set up your development environment, we can create a new Flutter project. Run the following command in your terminal or IDE to create a new Flutter project:

flutter create my_first_flutter_app

This command creates a new Flutter project my_first_flutter_app. In Flutter, applications are organized as widgets. The main widget tree in Flutter is called the MyApp widget, which is the root of your application.

Understanding Widgets

Widgets are the building blocks of a Flutter application. Widgets are everything from containers and images to buttons and inputs. There are two types of widgets in Flutter: Stateful and Stateless.

Stateless Widgets

Stateless widgets are immutable widgets. That means, once they are created, they cannot be modified. Stateless widgets are used for displaying information that never changes, like a static label, icon, or image.

Stateful Widgets

Stateful widgets maintain state and can change dynamically. That means they are suitable for handling user input or displaying data that changes over time. For instance, a userโ€™s name or the number of items in a shopping cart could change dynamically as the users interact with the app.

In our mobile app, we will use both types of widgets.

Building the User Interface

Building the user interface of a Flutter app is as easy as composing widgets. In this tutorial, we will create a simple UI that displays a welcome message, a text field for entering the userโ€™s name, and a button for navigating to the next screen.

We will use the MaterialApp widget as the root of our application. This widget provides many pre-built widgets and designs that fit the material design guidelines.

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'My First Flutter App',
      home: HomeScreen(),
    );
  }
}

Home Screen

We will start by building the home screen of our application. Open the home_screen.dart file and add the following code:

class HomeScreen extends StatelessWidget {
  final TextEditingController _nameController = TextEditingController();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('My First Flutter App'),
      ),
      body: Padding(
        padding: EdgeInsets.all(16.0),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text(
              'Welcome!',
              style: Theme.of(context).textTheme.headline4,
            ),
            SizedBox(
              height: 16.0,
            ),
            TextField(
              controller: _nameController,
              decoration: InputDecoration(
                border: OutlineInputBorder(),
                labelText: 'Enter your name',
              ),
            ),
            SizedBox(
              height: 16.0,
            ),
            RaisedButton(
              onPressed: () {
                Navigator.push(
                  context,
                  MaterialPageRoute(
                    builder: (context) => NextScreen(
                      name: _nameController.text,
                    ),
                  ),
                );
              },
              child: Text('Next'),
            )
          ],
        ),
      ),
    );
  }
}

The HomeScreen widget is a stateless widget that displays a welcome message, a text field, and a button. The text field is bound to a TextEditingController instance, which helps us to capture the text entered by the user.

Next Screen

We will create another screen that displays the userโ€™s name. Open the next_screen.dart file and add the following code:

class NextScreen extends StatelessWidget {
  final String name;

  const NextScreen({Key key, this.name}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Next Screen'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              'Your name is:',
              style: TextStyle(fontSize: 32.0),
            ),
            SizedBox(height: 16.0),
            Text(
              name,
              style: TextStyle(fontSize: 32.0),
            ),
            SizedBox(height: 16.0),
            RaisedButton(
              onPressed: () {
                Navigator.pop(context);
              },
              child: Text('Go back'),
            )
          ],
        ),
      ),
    );
  }
}

When the user clicks on the Next button, we navigate to the NextScreen widget. The NextScreen widget receives the name entered by the user as a parameter and displays it on the screen.

Deploying Your App

Once you have built and tested your app on a simulator or physical device, you are ready to deploy your app. Flutter provides an easy way to generate both Android and iOS apps.

Android Deployment

To build an APK (Android Package Kit) for your app, run the following command in the terminal or IDE:

flutter build apk

This command generates an APK file that you can install on any Android device.

iOS Deployment

To build an IPA (iOS Application Archive) for your app, you need to have a Mac computer with Xcode installed.

Follow these steps to build an IPA for your app:

  1. Open the project directory in Xcode.
  2. Select Product > Archive from the menu bar.
  3. Once the archive process is complete, click on the Distribute App button.
  4. Choose the appropriate distribution method for your app (App Store or Ad Hoc).
  5. Follow the rest of the prompts to generate the IPA for your app.

Conclusion

Flutter is a powerful and easy-to-use framework for building mobile applications. It offers an extensive set of widgets and tools that simplify the process of developing mobile apps. In this tutorial, we have covered everything you need to know to get started with Flutter and build your first mobile app.

We covered setting up your development environment, creating a new Flutter project, building your user interface, adding functionality to your app, and deploying your app to the app store. Make sure you explore the official Flutter documentation and try building more complex apps to take advantage of all the features that Flutter has to offer.

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