Flutter - Build and Release an Android App | App Signing

Summary

This video guides you through the process of preparing your Flutter app for production release on Android. It covers essential steps such as replacing the default app icon and name, signing the app with a keystore, configuring build settings, and ensuring compatibility with Android API levels. The video emphasizes the importance of signing the app for both publishing on the Play Store and testing on devices. It also provides instructions for building an app bundle and generating the APK, with helpful tips for version management and optimizing your app for the Play Store.

Takeaways

• 😀 Ensure that your app is ready for release by updating the default icon and app name.
• 😀 Use the `flutter_launcher_icons` package to generate custom app icons easily.
• 😀 Modify the `AndroidManifest.xml` to change the app's name and icon, and configure app permissions like internet access.
• 😀 To release your app on the Google Play Store, you must sign your app with a digital signature using a keystore.
• 😀 Generate a keystore by using specific commands for Mac or Windows, and make sure to keep your passwords secure.
• 😀 Store your keystore credentials in a private `key.properties` file and never check it into public source control.
• 😀 Configure the app's build settings in the `build.gradle` file to ensure proper signing of the release build.
• 😀 Review and adjust important Android build configurations, including the application ID, SDK versions, and version numbers.
• 😀 The `versionCode` and `versionName` in `build.gradle` determine the app's version and should be updated for each new release.
• 😀 Build your app using `flutter build appbundle` to generate an APK or app bundle for release on the Play Store.
• 😀 After building your release version, test the app before uploading it to the Play Store for publishing.

Q & A

What is the purpose of using the `flutter_launcher_icons` package?

The `flutter_launcher_icons` package is used to generate app icons for different Android and iOS resolutions, making it easier to customize the app icon and update it across multiple platforms.

How do you change the app name in a Flutter project?

To change the app name, you need to open the `AndroidManifest.xml` file located in `Android/app/src/main/` and modify the `android:label` attribute to the desired app name.

Why is it necessary to sign the app before releasing it on the Google Play Store?

Signing the app is necessary because it provides a digital signature that Google uses to verify the authenticity and integrity of the app. It also ensures that the app hasn't been tampered with after its release.

What is a key store, and how is it used for signing the app?

A key store is a file that contains cryptographic keys used for signing your app. It's essential for generating the release version of your app and ensuring that the Play Store can verify the authenticity of your app.

What command do you use to generate a key store on Mac?

On a Mac, you can generate a key store using the command `keytool -genkey -v -keystore ~/your-app-name.keystore -keyalg RSA -keysize 2048 -validity 10000 -alias your-key-alias`.

Where do you store the key properties for signing the app?

The key properties for signing the app are stored in a file called `key.properties` inside the `Android` folder. This file contains the keystore location, passwords, and alias information.

What happens if you change the application ID in the `build.gradle` file after releasing the app?

Changing the application ID after releasing the app will cause Google Play to treat the new version as a completely different app, which could result in the loss of existing users and their data.

How does the `version code` work in Android app development?

The `version code` is an integer used to track different versions of your app internally. It must increase with each new release, and it's used by the system to prevent users from installing an older version of the app.

What is the significance of the `minSdkVersion` and `targetSdkVersion` in the `build.gradle` file?

The `minSdkVersion` defines the lowest Android API level the app supports, while the `targetSdkVersion` indicates the API level the app is designed to work with. These values help ensure compatibility with different Android versions.

What is the recommended format for versioning the app using `versionName`?

The recommended format for `versionName` is a string of three numbers separated by dots (e.g., `1.0.0`), and it represents the visible version of the app that users can see. The version code, on the other hand, is an integer for internal versioning.