How to get a working vertical SeekBar in Android using Kotlin?

This example demonstrates how to listen for volume buttons in Android background service 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.

Example

<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:padding="8dp"    tools:context=".MainActivity">    <SeekBar       android:id="@+id/seekBar"       android:layout_width="match_parent"       android:layout_height="wrap_content"       android:layout_centerInParent="true"       android:rotation="270" />    <TextView       android:id="@+id/textView"       android:layout_width="wrap_content"       android:layout_height="wrap_content"       android:layout_alignParentTop="true"       android:layout_centerHorizontal="true"       android:text=""    android:textSize="16sp" /> </RelativeLayout>

Step 3 − Add the following code to src/MainActivity.kt

Example

import android.os.Bundle import android.widget.SeekBar import android.widget.SeekBar.OnSeekBarChangeListener import android.widget.TextView import androidx.appcompat.app.AppCompatActivity class MainActivity : AppCompatActivity() {    lateinit var seekBar: SeekBar    lateinit var textView: TextView    var min = 0    var max: Int = 100    var current: Int = 50    override fun onCreate(savedInstanceState: Bundle?) {       super.onCreate(savedInstanceState)       setContentView(R.layout.activity_main)       title = "KotlinApp"       textView = findViewById(R.id.textView)       seekBar = findViewById(R.id.seekBar)       seekBar.progress = max - min       seekBar.progress = current - min       textView.text = "" + current       seekBar.setOnSeekBarChangeListener(object : OnSeekBarChangeListener {          override fun onProgressChanged(seekBar: SeekBar, progress: Int, fromUser: Boolean) {             current = progress + min             textView.text = "" + current          }          override fun onStartTrackingTouch(seekBar: SeekBar) {}          override fun onStopTrackingTouch(seekBar: SeekBar) {}       })    } }

Step 4 − Add the following code to src/SettingsContentObserver.kt

Example

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="app.com.myapplication">    <application       android:allowBackup="true"       android:icon="@mipmap/ic_launcher"       android:label="@string/app_name"       android:roundIcon="@mipmap/ic_launcher_round"       android:supportsRtl="true"       android:theme="@style/AppTheme">       <activity android:name=".MainActivity">          <intent-filter>             <action android:name="android.intent.action.MAIN" />             <category android:name="android.intent.category.LAUNCHER" />          </intent-filter>       </activity>    </application> </manifest>

Let's try to run your application. I assume you have connected your actual Android Mobile device with your computer. To run the app from android studio, open one of your project's activity files and click the Run icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen