This example demonstrates how to call an activity method from a fragment in an Android App using Kotlin.Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml.         Step 3 − Add the following code to src/MainActivity.ktimport android.os.Bundle import android.widget.Toast import androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() {    override fun onCreate(savedInstanceState: Bundle?) {       super.onCreate(savedInstanceState)       setContentView(R.layout.activity_main)       title = "KotlinApp"       val fragmentManager ... Read More

This example demonstrates how to change spinner text size and text color in Android App using Kotlin.Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml.       Step 3 − Add the following code to src/MainActivity.ktimport android.os.Bundle import android.widget.ArrayAdapter import android.widget.Spinner import androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() {    lateinit var spinner: Spinner       override fun onCreate(savedInstanceState: Bundle?) {       super.onCreate(savedInstanceState)       setContentView(R.layout.activity_main)       title = ... Read More

This example demonstrates how to determine the size of an Android view at runtime using Kotlin.Step 1 − Create a new project in Android Studio, go to File? New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml.         Step 3 − Copy and paste an image (.png/.jpg/.jpeg) into res/drawableStep 4 − Add the following code to src/MainActivity.ktimport android.os.Bundle import android.view.View import android.view.ViewTreeObserver.OnGlobalLayoutListener import android.widget.ImageView import android.widget.TextView import androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() {    private lateinit var imageView: ImageView    override fun onCreate(savedInstanceState: Bundle?) { ... Read More

This example demonstrates how to disable copy/paste from/to EditText in the Android App using Kotlin.Step 1 − Create a new project in Android Studio, go to File? New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml.         Step 3 − Add the following code to src/MainActivity.ktimport android.os.Bundle import android.view.ActionMode import android.view.Menu import android.view.MenuItem import android.widget.EditText import androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() {    lateinit var editText: EditText    override fun onCreate(savedInstanceState: Bundle?) {       super.onCreate(savedInstanceState)       setContentView(R.layout.activity_main)       title ... Read More

This example demonstrates how to add calendar events in Android App using Kotlin?Step 1 - Create a new project in Android Studio, go to File? New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml.             Step 3 − Add the following code to src/MainActivity.ktimport android.content.Intent import android.os.Bundle import android.view.View import androidx.appcompat.app.AppCompatActivity import java.util.* class MainActivity : AppCompatActivity() {    override fun onCreate(savedInstanceState: Bundle?) {       super.onCreate(savedInstanceState)       setContentView(R.layout.activity_main)       title = "KotlinApp"    }    fun addCalendarEvent(view: ... Read More

This example demonstrates how to read a simple text file in an Android App using Kotlin.Step 1 − Create a new project in Android Studio, go to File? New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml.             Step 3 − Create a new Android Resource directory (raw.xml) and add a text file in the res/rawStep 4 − Add the following code to src/MainActivity.ktimport android.os.Bundle import android.view.View import android.widget.TextView import android.widget.Toast import androidx.appcompat.app.AppCompatActivity import java.io.BufferedReader import java.io.IOException import java.io.InputStream import java.io.InputStreamReader class MainActivity ... Read More

This example demonstrates how to animate the change of background color of a view on Android using Kotlin.Step 1 − Create a new project in Android Studio, go to File? New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml.             Step 3 − Add the following code to src/MainActivity.ktimport android.graphics.Color import android.graphics.drawable.ColorDrawable import android.graphics.drawable.TransitionDrawable import android.os.Bundle import android.widget.Button import android.widget.TextView import androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() {    lateinit var textView: TextView    lateinit var button: Button    override fun onCreate(savedInstanceState: Bundle?) { ... Read More

This example demonstrates how to delete SharedPreferences data for my Android App using Kotlin.Step 1 − Create a new project in Android Studio, go to File ? New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml.                 Step 3 − Add the following code to src/MainActivity.ktimport android.content.Context import android.content.SharedPreferences import android.os.Bundle import android.widget.Button import android.widget.TextView import androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() {    lateinit var textView: TextView    lateinit var tvAfterDelete: TextView    lateinit var sharedPreferences: SharedPreferences    lateinit var editor: ... Read More

This example demonstrates how to start a Service at Boot Time in an Android App using Kotlin.Step 1 − Create a new project in Android Studio, go to File? New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml.         Step 3 − Create a new kotlin class and add the following code in RunServiceOnBoot.ktimport android.app.Service import android.content.Intent import android.os.Handler import android.os.IBinder import android.util.Log import android.widget.Toast class RunServiceOnBoot : Service() {    private val TAG = "MyService"    private lateinit var handler: Handler    private lateinit ... Read More

This example demonstrates how to Check if Android EditText is empty in Kotlin.Step 1 − Create a new project in Android Studio, go to File? New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml.         Step 3 − Add the following code to src/MainActivity.ktimport android.os.Bundle import android.text.TextUtils import android.widget.Button import android.widget.EditText import android.widget.Toast import androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() {    lateinit var editText: EditText    lateinit var button: Button    override fun onCreate(savedInstanceState: Bundle?) {       super.onCreate(savedInstanceState)       setContentView(R.layout.activity_main)   ... Read More