How to get a working vertical seekBar in Android?

This example demonstrates how do I get a working vertical seekBar in android.
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.
<?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"
   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.java
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.SeekBar;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

   SeekBar seekBar;
   TextView textView;
   int min = 0, max = 100, current = 50;

   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);

      textView = findViewById(R.id.textView);
      seekBar = findViewById(R.id.seekBar);
      seekBar.setProgress(max - min);
      seekBar.setProgress(current - min);
      textView.setText("" + current);

      seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
         @Override
         public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
            current = progress + min;
            textView.setText("" + current);
         }

         @Override
         public void onStartTrackingTouch(SeekBar seekBar) { }

         @Override
         public void onStopTrackingTouch(SeekBar seekBar) { }
      });
   }
}
Step 4 - Add the following code to androidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
   package="app.com.sample">

   <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 Run  Icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen –