An Alert Dialog in Android is a small window that pops up on the screen to display important information, warnings, or confirmations to the user. It can be used to prompt the user for input, provide a message, or display an error.
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. Note that select Kotlin as the programming language.
Step 2: Working with the activity_main.xml file
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:gravity="center"    tools:context=".MainActivity">      <TextView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="Alert Dialog Boxes"        android:textStyle="bold"        android:textSize="20sp"/>        <Button        android:id="@+id/btn1"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:text="Button 1"        android:layout_margin="20dp"        android:backgroundTint="#4CAF50"        android:onClick="BTN1"/>      <Button        android:id="@+id/btn2"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:text="Button 2"        android:layout_margin="20dp"        android:backgroundTint="#4CAF50"        android:onClick="BTN2"/>      <Button        android:id="@+id/btn3"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:text="Button 3"        android:layout_margin="20dp"        android:backgroundTint="#4CAF50"        android:onClick="BTN3"/>  </LinearLayout> |
Step 3: Working with the MainActivity.java file
Go to the MainActivity.java file and refer to the following code. Below is the code for the MainActivity.java file.
Java
package com.anas.gfgalertdialog;  import androidx.appcompat.app.AlertDialog;import androidx.appcompat.app.AppCompatActivity;  import android.app.Dialog;import android.content.DialogInterface;import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.Toast;  public class MainActivity extends AppCompatActivity{      Button btn1,btn2,btn3;      @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);          btn1=findViewById(R.id.btn1);        btn2=findViewById(R.id.btn2);        btn3=findViewById(R.id.btn3);      }      public void BTN1(View v){        AlertDialog alert1=new AlertDialog.Builder(MainActivity.this).create();          alert1.setTitle("Alert Dialog 1");        alert1.setMessage("Alert Dialog with 1 Button");          alert1.setButton(Dialog.BUTTON_NEGATIVE,"Yes", new DialogInterface.OnClickListener() {            @Override            public void onClick(DialogInterface dialogInterface, int i) {                Toast.makeText(MainActivity.this,"Yes Clicked",Toast.LENGTH_SHORT).show();            }        });          alert1.show();    }      public void BTN2(View v){        AlertDialog.Builder alert2=new AlertDialog.Builder(MainActivity.this);          alert2.setTitle("Alert Dialog 2");        alert2.setMessage("Alert Dialog with 2 Buttons");          alert2.setPositiveButton("Yes", new DialogInterface.OnClickListener() {            @Override            public void onClick(DialogInterface dialogInterface, int i) {                Toast.makeText(MainActivity.this,"Yes Clicked",Toast.LENGTH_SHORT).show();            }        });          alert2.setNegativeButton("No", new DialogInterface.OnClickListener() {            @Override            public void onClick(DialogInterface dialog, int which) {                Toast.makeText(MainActivity.this,"No Clicked",Toast.LENGTH_SHORT).show();            }        });          alert2.show();    }      public void BTN3(View v){          AlertDialog.Builder alert3=new AlertDialog.Builder(MainActivity.this);          alert3.setTitle("Alert Dialog 3");        alert3.setMessage("Alert Dialog with 3 buttons");          alert3.setPositiveButton("Yes", new DialogInterface.OnClickListener() {            @Override            public void onClick(DialogInterface dialogInterface, int i) {                Toast.makeText(MainActivity.this,"Yes Clicked",Toast.LENGTH_SHORT).show();                MainActivity.super.onBackPressed();            }        });          alert3.setNegativeButton("No", new DialogInterface.OnClickListener() {            @Override            public void onClick(DialogInterface dialog, int which) {                Toast.makeText(MainActivity.this,"No Clicked",Toast.LENGTH_SHORT).show();            }        });          alert3.setNeutralButton("Cancel", new DialogInterface.OnClickListener() {            @Override            public void onClick(DialogInterface dialog, int which) {                Toast.makeText(MainActivity.this,"Cancel Clicked",Toast.LENGTH_SHORT).show();            }        });          alert3.show();      }} |
Step 4:
Run the app.
Screenshot (Output):
activity_main.xml
Step 5:
Click on Button 1.
Screenshot (Output) :
Alert Dialog with 1 Button
Step 6:
Click on Button 2.
Screenshot (Output):
Alert Dialog with 2 Buttons
Step 7:Â
Click on Button 3.
Screenshot (Output):
Alert Dialog with 3 Buttons
