In Android, a Switch is a type of button that lets the user toggle between two actions or instances. In general, a Switch is used for selecting one between two options that can be invoking any actions or functions. In this article, we are going to see how we can save the state of the Switch Button in android.
What we are going to build in this article?
Here is a sample video of what we are going to build in this article. Note that we will be using Java language to make this project.
Step by Step Implementation
Step 1: Create a New Project
- Open a new project.
- We will be working on Empty Activity with language as Java. Leave all other options unchanged.
- Name the application at your convenience.
- There will be two default files named activity_main.xml and MainActivity.java.
If you don’t know how to create a new project in Android Studio then you can refer to How to Create/Start a New Project in Android Studio?
Step 2. Working on XML files
Navigate to the app > res > layout > activity_main.xml and add the below code to that file. Below is the code for the activity_main.xml file.
XML
<?xml version="1.0" encoding="utf-8"?><LinearLayout android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" android:padding="16dp" android:gravity="center" tools:context=".MainActivity"> <androidx.appcompat.widget.SwitchCompat android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/switch_compat" android:text="Switch" android:textSize="25sp"/> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="20dp"> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="1" android:id="@+id/bt_next" android:text="next"/> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="1" android:id="@+id/bt_exit" android:text="Exit"/> </LinearLayout></LinearLayout> |
Navigate to app > right-click < new < activity < empty activity and name it as MainActivity2. Use the following code in activity_main2.xml file-
XML
<?xml version="1.0" encoding="utf-8"?><LinearLayout android:orientation="vertical" android:gravity="center" android:layout_width="match_parent" android:layout_height="match_parent" tools:context=".MainActivity2"> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Second Activity" android:textSize="30sp"/> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/bt_back" android:text="back"/></LinearLayout> |
Step 3. Working on Java files
Navigate to the MainActivity.java file and use the following code in it. Comments are added to the code to have a better understanding.
Java
package com.example.savestateofswitch;import androidx.appcompat.app.AppCompatActivity;import androidx.appcompat.widget.SwitchCompat;import android.content.Intent;import android.content.SharedPreferences;import android.os.Bundle;import android.view.View;import android.widget.Button;public class MainActivity extends AppCompatActivity { // Initialize variable SwitchCompat switchCompat; Button btNext,btExit; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // Assign variable switchCompat=findViewById(R.id.switch_compat); btNext=findViewById(R.id.bt_next); btExit=findViewById(R.id.bt_exit); // Save switch state in shared preferences SharedPreferences sharedPreferences=getSharedPreferences("save",MODE_PRIVATE); switchCompat.setChecked(sharedPreferences.getBoolean("value",true)); switchCompat.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { if (switchCompat.isChecked()) { // When switch checked SharedPreferences.Editor editor=getSharedPreferences("save",MODE_PRIVATE).edit(); editor.putBoolean("value",true); editor.apply(); switchCompat.setChecked(true); } else { // When switch unchecked SharedPreferences.Editor editor=getSharedPreferences("save",MODE_PRIVATE).edit(); editor.putBoolean("value",false); editor.apply(); switchCompat.setChecked(false); } } }); btNext.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { // Go to next activity Intent intent=new Intent(MainActivity.this,MainActivity2.class); startActivity(intent); } }); btExit.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { // Close the app MainActivity.this.finishAffinity(); } }); }} |
Navigate to the MainActivity2.java file and use the following code in it. Comments are added to the code to have a better understanding.
Java
package com.example.savestateofswitch;import androidx.appcompat.app.AppCompatActivity;import android.content.Intent;import android.os.Bundle;import android.view.View;import android.widget.Button;public class MainActivity2 extends AppCompatActivity { // Initialize variable Button btBack; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main2); // Assign variable btBack=findViewById(R.id.bt_back); btBack.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { // Go back Intent intent=new Intent(MainActivity2.this,MainActivity.class); startActivity(intent); } }); }} |
Here is the final output of our application.
Output:
