brightness control in android source code

hello, android developer today I will tell you how to make a brightness control app using android studio. or how to use seekbar with your android activity.

XML (activity_main.xml)

<android.support.constraint.ConstraintLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >

    <SeekBar
        android:id="@+id/backlightcontrol"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_margin="10px"
        android:layout_marginTop="32dp"
        android:max="100"
        android:progress="50"
        app:layout_constraintBottom_toTopOf="@+id/backlightsetting"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/backlightsetting"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="8dp"
        android:layout_marginBottom="32dp"
        android:text="0.50"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/backlightcontrol" />

</android.support.constraint.ConstraintLayout>

JAVA (MainActivity.java)

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.SeekBar;
import android.widget.TextView;
import android.view.WindowManager;

public class Changescreenbrightness extends AppCompatActivity {

    float BackLightValue = 0.5f;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_changescreenbrightness);

        SeekBar BackLightControl = (SeekBar)findViewById(R.id.backlightcontrol);
        final TextView BackLightSetting = (TextView)findViewById(R.id.backlightsetting);


        BackLightControl.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener(){
            @Override
            public void onProgressChanged(SeekBar arg0, int arg1, boolean arg2) {
                BackLightValue = (float)arg1/100;
                BackLightSetting.setText(String.valueOf(BackLightValue));
                WindowManager.LayoutParams layoutParams = getWindow().getAttributes();
                layoutParams.screenBrightness = BackLightValue;
                getWindow().setAttributes(layoutParams);

            }

            @Override
            public void onStartTrackingTouch(SeekBar arg0) {

            }

            @Override
            public void onStopTrackingTouch(SeekBar arg0) {

            }});
    }
}