App Development

  Adding Libraries Using Gradle in Android Gradle is the build automation tool used in Android development to manage dependencies, build processes, and more. Steps to Add a Library Using Gradle: Open the build.gradle File: There are two build.gradle files in an Android project: one at the project level and one at the module level (usually app/build.gradle ). Add dependencies in the module-level build.gradle file. Add the Dependency: Locate the dependencies block in your build.gradle file and add the desired library. gradle Copy code dependencies { implementation 'com.github.bumptech.glide:glide:4.11.0' annotationProcessor 'com.github.bumptech.glide:compiler:4.11.0' } Sync the Project: After adding the dependency, click "Sync Now" in the bar that appears or select "Sync Project with Gradle Files" from the File menu to download and integrate the library. Examples of Useful Libraries: Glide : An image loading and caching library for Android...

  Activity and Fragment Lifecycle in Android Understanding the lifecycle of Activities and Fragments is crucial for managing resources, ensuring a smooth user experience, and avoiding memory leaks. Activity Lifecycle: onCreate() : Called when the activity is first created. Initialize the activity, set the content view, and perform setup tasks. kotlin Copy code override fun onCreate (savedInstanceState: Bundle ?) { super .onCreate(savedInstanceState) setContentView(R.layout.activity_main) // Initialize components } onStart() : Called when the activity becomes visible to the user. kotlin Copy code override fun onStart () { super .onStart() // The activity is about to become visible } onResume() : Called when the activity starts interacting with the user. kotlin Copy code override fun onResume () { super .onResume() // The activity has become visible and interactive } onPause() : Called when the system is about to start resuming another activity...

  Making HTTP Requests in Android Using Retrofit Retrofit is a type-safe HTTP client for Android and Java, which simplifies making HTTP requests and handling responses. Setting Up Retrofit: Add Retrofit Dependency: Add the following dependencies to your build.gradle file: gradle Copy code implementation 'com.squareup.retrofit2:retrofit:2.9.0' implementation 'com.squareup.retrofit2:converter-gson:2.9.0' Create an API Interface: kotlin Copy code import retrofit2.Call import retrofit2.http.GET interface ApiService { @GET( "posts" ) fun getPosts () : Call<List<Post>> } Define a Data Model: kotlin Copy code data class Post ( val userId: Int , val id: Int , val title: String, val body: String ) Initialize Retrofit: kotlin Copy code import retrofit2.Retrofit import retrofit2.converter.gson.GsonConverterFactory val retrofit = Retrofit.Builder() .baseUrl( "https://jsonplaceholder.typicode.com/" ) ...

   SQLite is a lightweight, relational database management system embedded within Android and iOS. It is ideal for storing structured data in mobile applications. Setting Up SQLite in Android: Creating a Database Helper Class: kotlin Copy code import android.content.Context import android.database.sqlite.SQLiteDatabase import android.database.sqlite.SQLiteOpenHelper class DatabaseHelper (context: Context) : SQLiteOpenHelper(context, DATABASE_NAME, null , DATABASE_VERSION) { companion object { private const val DATABASE_NAME = "example.db" private const val DATABASE_VERSION = 1 } override fun onCreate (db: SQLiteDatabase ) { val createTable = "CREATE TABLE users (id INTEGER PRIMARY KEY, name TEXT, age INTEGER)" db.execSQL(createTable) } override fun onUpgrade (db: SQLiteDatabase , oldVersion: Int , newVersion: Int ) { db.execSQL( "DROP TABLE IF EXISTS users" ) onCre...