Android app development free pdf book

Chapter 1: Getting Started with Android Overview Android is an open-source operating system developed by Google. Android applications are mainly built using Java or Kotlin. Apps run on the Android Runtime (ART). Android apps are packaged as APK (Android Package) or AAB (Android App Bundle). Android Architecture Linux Kernel Hardware Abstraction Layer (HAL) Native Libraries Android Runtime (ART) Application Framework Applications Android Components Activity – Represents a single screen. Service – Runs tasks in the background. Broadcast Receiver – Receives system-wide broadcasts. Content Provider – Shares data between applications. Android Project Structure app/ java/ res/ AndroidManifest.xml Gradle Scripts Resource Folders drawable/ – Images layout/ – XML layouts mipmap/ – App icons values/ – Colors, strings, dimensions menu/ – Menu XML files AndroidManifest.xml Declares application information. Registers Activities and Services. Requests permissions. Defines app theme and launcher activity. Activity Lifecycle onCreate() onStart() onResume() onPause() onStop() onRestart() onDestroy() Creating Your First App Install Android Studio. Create a New Project. Choose template. Configure application. Write code. Run on Emulator or Physical Device. Build Process Source Code Compilation Resource Processing DEX Conversion APK/AAB Generation Android Versions Android 5.0 (Lollipop) Android 6.0 (Marshmallow) Android 7.0 (Nougat) Android 8.0 (Oreo) Android 9 (Pie) Android 10 Android 11 Android 12 Android 13 Android 14+ Chapter 2: Android Studio Overview Official IDE for Android development. Based on IntelliJ IDEA. Supports Java, Kotlin, C++, and Flutter. Main Features Smart Code Editor Code Completion Layout Editor Emulator Gradle Build System Profiler Logcat Debugger Version Control (Git) Android Studio Interface Toolbar Project Window Editor Window Logcat Terminal Build Output Device Manager Creating a Project Open Android Studio. Click New Project. Select template. Choose language (Java/Kotlin). Select Minimum SDK. Finish. Important Files MainActivity.java / MainActivity.kt activity_main.xml AndroidManifest.xml build.gradle settings.gradle gradle.properties Gradle Dependency management. Build automation. Supports build variants. Handles APK generation. Example dependency: dependencies { implementation 'androidx.appcompat:appcompat:1.7.0' } Emulator Virtual Android device. Configured using Device Manager. Useful for testing without a physical device. Logcat Displays runtime logs. Used for debugging. Example: Log.d("TAG", "Hello Android"); Debugging Set breakpoints. Step Into Step Over Inspect variables. View Call Stack. Layout Editor Drag-and-drop UI designer. XML editing. Preview screen. ConstraintLayout support. Device Manager Create Virtual Devices. Start/Stop Emulator. Configure hardware profiles. Useful Keyboard Shortcuts Shift + Shift – Search Everywhere Ctrl + N – Search Class Ctrl + Shift + N – Search File Ctrl + Alt + L – Format Code Alt + Enter – Quick Fix Ctrl + Space – Code Completion Ctrl + / – Toggle Comment Shift + F10 – Run App Shift + F9 – Debug App Profiler CPU Monitoring Memory Monitoring Network Monitoring Energy Monitoring APK Analyzer View APK contents. Check APK size. Analyze resources and classes. Best Practices Keep Android Studio updated. Use Kotlin for new projects. Organize project files properly. Use Gradle dependencies effectively. Test on both emulator and physical devices. Use Logcat and Debugger to identify issues. Regularly sync Gradle after dependency changes