How to create Night Mode in our app in android studio

Hello friend today we will learn about how to create night mode in our app in android studio.Today we use many time use of dark mode in our app.

We can use this method in any of our apps and can also do it very easily.Let's see how we implement it in our app.

activity_main

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">
    <Button
        android:id="@+id/btn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Dark theme"
        android:textColor="@color/white"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

MainActivity

package com.example.darknightmode;

import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.app.AppCompatDelegate;

import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity {
 private Button darkBtn;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        getSupportActionBar().setBackgroundDrawable(getDrawable(R.color.purple_500));
        darkBtn=findViewById(R.id.btn);
        SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
        final SharedPreferences.Editor editor = sharedPreferences.edit();
        final boolean isDarkMode = sharedPreferences.getBoolean("isDarkMode", false);
        if (isDarkMode) {
            AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_NO);
            darkBtn.setText("Dark mode on");
        } else {

            AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES);
            darkBtn.setText("Dark mode off");

        }
        darkBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {


                    if (isDarkMode) {

                        AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES);
                        editor.putBoolean("isDarkMode", false);
                        editor.apply();

                    }
                 else {

                    AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_NO);
                    editor.putBoolean("isDarkMode", true);

                    editor.apply();


                }
            }

        });
    }
}

Thanks ............