How to create an Android build?

An Android build is the process of compiling your app’s source code and resources into an APK file that you can run on Android devices. Creating an Android build is an essential step in Android app development, as it allows you to test your app, deploy it to devices, and ultimately publish your app to the Google Play Store or other app marketplaces.

You need to create Android builds regularly throughout the development process to test new features, catch bugs early, and validate your changes. Building your Android app produces an APK package that bundles up the app code and resources optimized for running on Android. Without creating Android builds, you won’t be able to deploy or share your app for others to use.

Requirements

To build an Android app, you’ll need to have the Android SDK and Java JDK installed on your development machine. The Android SDK provides all of the tools and libraries you need for Android development, while the JDK is required to compile your Java code.

The minimum requirement is the Android SDK API level 26 or higher, along with revision level 3. To get started, download and install the latest version of the Android Studio IDE, which bundles the Android SDK, emulator system images, and build tools. Android Studio also includes an integrated version of the Java JDK.

Once you’ve installed Android Studio, the next step is to configure your SDK by downloading the SDK platforms and tools you need through the SDK Manager. At minimum, you’ll want to install the latest SDK platform for the version of Android you are targeting, as well as the build tools, platform tools, emulator, and any other dependencies required by your app.

With the prerequisites installed, you’ll have the necessary tools to start building and running Android apps. Just be sure to periodically update your SDK components to get access to the latest APIs and fixes.

Configure build settings

In order to create an Android build, the first step is to configure the build settings in Unity. This involves setting the correct target SDK version and minimum SDK version for your Android app.

The target SDK version refers to the latest Android SDK that your app is optimized for. This allows you to access the newest APIs and features available. Typically you want to set the target SDK version to the latest stable version of Android. According to https://zoransasko.medium.com/creating-simple-ar-app-in-unity3d-using-arcore-4c0ef0c72c6e, you can go to File > Build Settings in Unity and under the Android section, select the highest API level for the Target API Level.

The minimum SDK version is the lowest Android version your app supports. This ensures your app can run on devices with older Android versions. You want to set this appropriately based on your target audience. As noted in https://www.reddit.com/r/QtFramework/comments/hbj2di/all_essential_packages_installed_for_all/, a common issue is having the “All essential packages installed” showing red in build settings when the minimum SDK version is set too high.

Write Code

A key part of creating an Android build is writing the actual code that powers the app. This involves using languages like Java or Kotlin to write the logic and functionality, defining resources like images and strings, and configuring components in the Android manifest file.

Some best practices when writing Android code include:

• Use Kotlin over Java when possible for cleaner, more concise code.
• Organize code into packages and classes based on features and responsibilities.
• Define drawable, string, and other resources in XML files and access them programmatically.
• Configure key components like activities, services, broadcast receivers, etc. in the AndroidManifest.xml.
• Follow best practices like view binding, view models, repository pattern, dependency injection, etc.
• Write code that works across different Android OS versions and screen sizes using techniques like constraint layouts.
• Comment code thoroughly for future maintainability.

Thoroughly testing code using the Android emulator and real devices is also critical before moving to the build stage. Resources like the
Is there any way to build WebRTC in an Android app?
Quora thread can provide code samples and advice.

Run build

To build and generate the APK/AAB package for your Android app, you will use the Gradle build system. Gradle allows you to automate and customize the build process. Here are the steps to run a build with Gradle:

1. Open the Android Studio project and locate the app module’s build.gradle file. This contains the build configurations.

2. Connect an Android device to your computer or launch an emulator. Gradle will install and run the app on the device/emulator.

3. From Android Studio, select Build > Make Project from the menu. You can also click the hammer icon in the toolbar to build the project.

4. Gradle will now clean, compile, package and install the debug APK/AAB on the connected device/emulator. Any errors will be displayed in the Build window.

5. Verify the freshly built app launches and runs as expected on the device/emulator. Check the functionality and UI.

6. Repeat steps 3-5 as necessary while developing your app. Each time you request a build, Gradle will incrementally build only what changed.

This allows you to quickly build, test and iterate on your Android app project using Gradle. You can further customize the build process by tweaking the Gradle scripts.

Sign build

Signing the Android build is an important step before releasing it. This allows you to identify yourself as the author of the app. There are two types of signing keys – release and debug. The release key should be used when generating a final build for the Play Store. The debug key is automatically generated by Android Studio and can be used for development builds. [1]

To sign with a release key, you need a keystore containing your private key. This can be generated through keytool or Android Studio. Make sure to keep the keystore and passwords safe. In your app’s build configuration, specify the location of the keystore, alias, and passwords. Then build your app to generate a signed APK or app bundle. [2]

Signing with a debug key doesn’t require any extra configuration. Just build your app normally and Android Studio will automatically sign it with the debug key for testing. You can also generate new debug keys as needed. Remember to always use your release key when building for production. [3]

Test build

After generating the signed build, the next step is to install it on an emulator or physical device to test the functionality. This allows you to verify that the app runs as expected before publishing it to end users.

To test on an emulator, simply drag and drop the signed .apk file onto the emulator window to trigger installation. For physical devices, transfer the .apk file via USB cable or over WiFi and open it to install.

When testing, run through all critical app flows and features to check for crashes, errors or unexpected behavior. Check that the app logic works correctly in response to user input. Verify the UI displays properly on the target device(s). Check that all assets like images, audio and video are loading properly.

Rigorously test all edge cases and ensure security measures like input validation are working. Refer to recommended app security best practices while evaluating security.

Automated tests provide additional confidence, so consider creating UI tests, unit tests and integration tests to cover key scenarios. Tests that run on emulators and devices can catch issues before release.

Testing is crucial for delivering a quality user experience. Spend adequate time testing on real devices to confirm your Android build works as expected before publishing.

Publish build

Once you have completed testing and are ready to release your Android app, the next step is to publish it to the Play Store or another app store. To publish to the Play Store, you will need to create a developer account and pay a one-time $25 registration fee. Then, you can upload your signed release APK or Android App Bundle in the Play Console. The Play Store will run some automated checks and start rolling out your app to users within a few hours.

According to the Unity forum post “New Error Publishing Android Build,” one common issue is encountering an error during publishing related to your app’s target SDK version [1]. Make sure to test your build thoroughly and set the proper target SDK before trying to publish.

Other app stores like Amazon Appstore, Aptoide, and Itch.io have their own publishing workflows. Carefully review each store’s developer documentation to submit your app successfully. With Aptoide in particular, you can publish an app without any registration or fees. However, you may not get as much visibility as with the Play Store. Evaluate different stores based on your target audience and monetization strategy.

Update build

Updating an Android build involves making changes to the code, incrementing the version number, and then rebuilding the app. Here are the steps:

1. Make code changes as needed – this may involve fixing bugs, adding new features, or tweaking the UI. All code changes should be properly tested.
2. Increment the version number in the AndroidManifest.xml file. This is typically done by incrementing the versionCode integer and updating the versionName string. For example:

   android:versionCode="2" 
   android:versionName="1.1"
   

3. Rebuild the app either through Android Studio or using command line tools like Gradle. This compiles the new code and generates a new APK.
4. Run tests on the rebuilt app to ensure no new bugs were introduced.
5. You can then distribute the updated build via the Play Store or other channels. Be sure to include release notes detailing changes.

Following semantic versioning best practices for the version name can help communicate the scope of changes to users. Overall, updating builds helps provide users with new features and bug fixes.

Troubleshoot issues

When creating and testing Android builds, you may occasionally encounter issues that prevent the build from working properly. Common build issues include build errors, bugs, crashes, performance problems, and compatibility issues across different devices.

If you run into a build error, carefully inspect the error message and stack trace. Identify exactly where in the build process the failure is happening. Common causes include syntax errors in code, missing dependencies and resources, invalid configurations, and conflicts with dependencies. Review related code changes and configuration changes that could have introduced the error. Refer to documentation of any third party libraries and tools to troubleshoot the error.

Compile and runtime bugs can also cause problems. Log statements and stack traces can help narrow down exactly where in the code the issue is happening. Add additional validation and error handling to prevent crashes. Check API usage and review functionality that has recently changed. Refer to Android build troubleshooting guides for common bug and crash scenarios.

Performance issues like slow load times or laggy animations should be measured and profiled early in the development process. The Android profiler tools can pinpoint problem areas related to CPU usage, memory leaks, excessive overdraw and GPU rendering issues. Refer to Android documentation on profiling and monitoring performance.

Testing on various target devices is also crucial, as hardware differences can lead to compatibility issues and anomalies. Strive for maximum device coverage during QA. Adjust configurations and code as needed to stabilize performance across multiple architectures. Set up release channels or use a third party service to catch device-specific exceptions. Check the Android Compatibility program guides to ensure full compliance.

Staying proactive, following best practices, and addressing problems systematically are key when troubleshooting Android build issues.