HOW TO RUN ANDROID APP
In Android, an app is a collection of files and code that runs on an Android device. These apps are managed by the Android operating system, which is responsible for starting, stopping, and managing the app’s processes.
When an app is launched on an Android device, the operating system creates a new process for the app, which runs in the background. This process is responsible for executing the app’s code and managing its resources, such as memory and network connections.
The Android operating system uses a process management system known as the “Android Runtime” (ART) to manage app processes. ART is responsible for allocating memory and other resources to app processes, and for scheduling the execution of the app’s code.
Each app process runs in its own Linux process, with its instance of the Dalvik virtual machine. The Dalvik VM is a virtual machine that is optimized for Android and runs Java code. Each app process has its instance of the Dalvik VM, which runs the app’s code in a separate environment.
Launching the app
When an app is launched, the Android operating system creates a new Linux process for the app and creates a new instance of the Dalvik VM within that process. The app’s code is then loaded into the Dalvik VM, and the Dalvik VM starts executing the app’s code.
While an app is running, the Android operating system monitors the app’s process and will stops or kill the process if it is using too many resources, or if the user navigates away from the app.
Foreground and background process
There are two important types of processes in android:
1: Foreground and 2: background.
Foreground process: the process that is running currently in the foreground and interacting with the user. The system will give a high priority to these processes, so they will not be killed easily.
Background process: the process that is not running in the foreground. The system can kill background processes to free up resources, as they don’t need to be running for the app to function correctly.
However, Android also has a feature called “services” that allow apps to run background processes that are not associated with an active user interface. Services can be used to perform tasks such as playing music, downloading files, or sending and receiving network data, even when the user is not actively using the app.
In summary, Android manages app processes by creating a new Linux process and instance of the Dalvik VM for each app and using ART to allocate resources and schedule the execution of the app’s code. The operating system also monitors app processes and will stop or kill them if they are using too many resources, or if the user navigates away from the app.
WHAT IS ADB?
ADB, or Android Debug Bridge, is a command-line tool that is used to develop and debug Android applications.
ADB is a powerful tool that allows developers to interact with their Android device or emulator in a variety of ways. It is included in the Android SDK (Software Development Kit) and is used to perform a wide range of tasks, including
- Installing and uninstalling apps
- Copying files to and from the device
- Running shell commands on the device
- Debugging apps using JDWP (Java Debug Wire Protocol)
- Profiling apps using method tracing
- Capturing screenshots and videos of the device’s screen
Install android sdk
To use ADB, a developer must first install the Android SDK on their computer and set up their device or emulator for debugging. Once this is done, ADB can be used to interact with the device or emulator through the command line.
Another important component of ADB is the ADB daemon running on the device side. It runs as a background process and allows the command-line client on the host machine to interact with it.
WHAT IS AVD?
AVD, or Android Virtual Device, is an emulator that allows developers to test and debug their Android applications on a computer,
without the need for a physical Android device. An AVD is a configuration that defines the characteristics of an Android device, such as its screen resolution, memory size, and Android version.
A developer can create an AVD using the AVD Manager, which is a tool included in the Android SDK. Once an AVD is created, it can be used to run and test Android apps, just like a physical Android device. The developer can also configure an AVD to use specific Android versions, including different API levels, custom skins, and hardware properties.
AVDs are especially useful for developers who are developing apps for multiple different Android devices, as it allows them to test their apps on a variety of different device configurations without needing to have physical access to each device. It also allows developers to test their apps on older versions of Android, which can be useful for compatibility testing.
In conclusion, understanding how to run an Android app is crucial for any developer aiming to bring their creations to life. The process involves multiple steps, from coding and designing the app to testing and deployment. Android Studio, the official integrated development environment (IDE), plays a central role in this journey, offering a user-friendly interface, advanced debugging tools, and an array of resources to simplify app development.
Running an Android app involves various methods, such as deploying it on a physical device or using an emulator to simulate different Android environments. The choice between these options depends on factors like testing requirements, device availability, and user experience. Emulators are powerful tools that facilitate testing on various screen sizes and Android versions, ensuring the app’s compatibility across a wide range of devices.
The Android Virtual Device (AVD) Manager within Android Studio allows developers to create and manage virtual devices with specific configurations, enabling accurate testing before deploying to actual hardware. Additionally, tools like ADB (Android Debug Bridge) and the Logcat feature help diagnose issues and monitor app performance during runtime.
Once the app is ready for deployment, developers can build an APK (Android Package) file that encapsulates the app’s resources, code, and manifest. These APK files can then be distributed through various channels, such as the Google Play Store or other third-party app stores. Moreover, developers can opt for manual installation on devices for testing purposes.
In this journey, developers encounter challenges and milestones that contribute to their growth and proficiency in Android app development. They learn to optimize code, enhance UI/UX, and ensure robust functionality. By mastering the art of running Android apps and navigating the intricacies of Android Studio, developers can bring their innovative ideas to life and contribute to the dynamic landscape of mobile applications.
Q: 1. How do I run an Android app in Android Studio?
A: To run an Android app in Android Studio, ensure that your project is open, select the desired emulator or physical device from the list of available devices, and click the “Run” button (green triangle) located in the toolbar. The app will be built and launched on the selected device.
Q: 2. Can I run my app on a physical device instead of an emulator?
A: Yes, you can run your app on a physical Android device by connecting it to your computer via USB and enabling Developer Options and USB Debugging on the device. Once connected, your device will appear in Android Studio’s device list, and you can choose it to run your app.
Q: 3. What is the benefit of using an emulator to run my app?
A: Emulators allow you to test your app on a variety of virtual devices with different screen sizes, Android versions, and hardware configurations. This helps ensure that your app is compatible with a wide range of devices before actual deployment.
Q: 4. How do I create a virtual device using the Android Virtual Device (AVD) Manager?
A: To create a virtual device, open the AVD Manager in Android Studio, click “Create Virtual Device,” choose a hardware profile, select a system image (Android version), and configure other settings. This creates a virtual device that you can use to run and test your app.
Q: 5. What is an APK file, and how do I run my app using it?
A: An APK (Android Package) file is the installation package for Android apps. To run your app using an APK file, you need to build the APK from your Android Studio project and then transfer it to a device. You can install the APK manually on a device by opening it.
Q: 6. Is there a way to debug my app while running it?
A: Yes, Android Studio provides powerful debugging tools to identify and fix issues while your app is running. You can set breakpoints, inspect variables, use the Logcat tool to monitor logs, and step through your code to understand and resolve errors.
Q: 7. Can I test my app on multiple Android versions using emulators?
A: Yes, you can create multiple virtual devices in the AVD Manager, each using a different system image (Android version). This allows you to test your app on various Android versions and ensure its compatibility across different platforms.
Q: 8. How can I optimize my app’s performance while running it?
A: Android Profiler in Android Studio helps you monitor your app’s CPU, memory, network, and battery usage while it’s running. By analyzing this data, you can identify performance bottlenecks and optimize your app for a smoother experience.
Q: 9. What if I encounter errors while running my app?
A: If you encounter errors or crashes while running your app, Android Studio’s debugging tools can help you diagnose and fix issues. Review the Logcat output and use breakpoints to inspect variables and trace the source of the problem.
Q: 10. Can I share my app with others for testing before releasing it?
A: Yes, you can share the APK file of your app with others for testing purposes. Distribute the APK via email, cloud storage, or any other method. However, ensure that the recipients understand that the app is still in testing and might have some issues.