When we want to implement an exit AlertDialog in our android application we have to programmatically exit our android application. In this article, we will take a look at How to Quit the Android application programmatically. We will be adding a button and on clicking on that button we will be closing our application. A sample video is given below to get an idea about what we are going to do in this article.
Note: This Android article covered in both Java and Kotlin languages.Â
Step by Step Implementation
Step 1: Create a New Project in Android Studio
To create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio.
Step 2: Working with the activity_main.xml file
Navigate to app > res > layout > activity_main.xml and add the below code to it. Comments are added in the code to get to know in detail.Â
XML
<?xml version="1.0" encoding="utf-8"?><RelativeLayout    android:id="@+id/idRLContainer"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical"    tools:context=".MainActivity">      <!--on below line we are creating        a text for our app-->    <TextView        android:id="@+id/idTVHeading"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:layout_above="@id/idBtnCloseApplication"        android:layout_centerInParent="true"        android:layout_margin="20dp"        android:gravity="center"        android:padding="10dp"        android:text="Click the button to close the application"        android:textAlignment="center"        android:textColor="@color/black"        android:textSize="20sp"        android:textStyle="bold" />      <!--on below line we are creating a button-->    <Button        android:id="@+id/idBtnCloseApplication"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:layout_centerInParent="true"        android:layout_margin="20dp"        android:text="Close the application"        android:textAllCaps="false" />  </RelativeLayout> |
Step 3: Working with the MainActivity fileÂ
Navigate to app > java > your app’s package name > MainActivity file and add the code below. Comments are added in the code to get to know in detail.Â
Kotlin
package com.gtappdevelopers.kotlingfgproject  import android.os.Bundleimport android.widget.Buttonimport androidx.appcompat.app.AppCompatActivity  class MainActivity : AppCompatActivity() {      // on below line we are creating a variable.    lateinit var closeApplicationBtn: Button      override fun onCreate(savedInstanceState: Bundle?) {        super.onCreate(savedInstanceState)        setContentView(R.layout.activity_main)          // on below line we are creating and         // initializing variable for activity        val activity: MainActivity = MainActivity()          // on below line we are initializing our variables.        closeApplicationBtn = findViewById(R.id.idBtnCloseApplication)          // on below line we are adding click listener for our button        closeApplicationBtn.setOnClickListener {            // on below line we are finishing activity.            activity.finish()              // on below line we are exiting our activity            System.exit(0)        }    }} |
Java
package com.gtappdevelopers.kotlingfgproject;  import android.os.Bundle;import android.view.View;import android.widget.Button;import androidx.appcompat.app.AppCompatActivity;  public class MainActivity extends AppCompatActivity {      // on the below line we are creating a variable.    private Button closeApplicationBtn;      @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);          // on below line we are initializing variables with ids.        closeApplicationBtn = findViewById(R.id.idBtnCloseApplication);          // on below line we are adding click listener for our button        closeApplicationBtn.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                // on below line we are finishing activity.                MainActivity.this.finish();                                // on below line we are exiting our activity                System.exit(0);            }        });    }} |
Now run your application to see the output of it.Â
Output:
