Android App
Building blocks of the Android ecosystem
App Structure
An Android app is a package (APK) containing code, resources, and a manifest. It consists of components that interact with the system and users.
Core Components
Activities
UI screens for user interaction and navigation between different parts of the app.
Services
Background tasks without UI that can run independently of activities.
Broadcast Receivers
Respond to system-wide events and notifications from other apps.
Content Providers
Manage shared app data and provide data access to other applications.
App Resources
Resources are non-code assets like images, strings, and layouts. They are kept separate from code to allow independent maintenance.
- Layouts (XML): Define the UI structure.
- Strings: distinct text values for localization.
- Drawables: Images and icons.
- Manifest: Metadata about the app.
App Lifecycle
Android manages app components' lifecycles, ensuring efficient resource use and smooth user experience. Developers must handle state transitions and resource cleanup.
Interaction with OS
- Apps communicate with the OS via the Framework and system services.
- Permissions control access to sensitive features and device resources.
- Apps can interact with each other using Intents and Content Providers.
- Background processing is managed through Services and WorkManager.
Learn More
Explore the official Android app development documentation for comprehensive guides.
Android App Fundamentals