Android Program to Show Alert Box

Write an android program to display an alert box with OK and Cancel.

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:text="Show Alert" />
</RelativeLayout>

MainActivity.java

package com.teachics.alertbox;

import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;

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 but;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        but=(Button) findViewById(R.id.button);
        but.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                AlertDialog.Builder b= new AlertDialog.Builder(MainActivity.this);
                b.setTitle("Alert");
                b.setMessage("Are you sure ?");
                b.setPositiveButton("OK", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface arg0, int arg1) {
                        Toast.makeText(MainActivity.this, "You Clicked OK",
                                Toast.LENGTH_SHORT).show();
                    }
                });
                b.setNegativeButton("Cancel", new DialogInterface.OnClickListener()
                {
                    @Override
                    public void onClick(DialogInterface arg0, int arg1) {
                        Toast.makeText(MainActivity.this, "You Clicked Cancel",
                                Toast.LENGTH_SHORT).show();
                    }
                });
                AlertDialog d = b.create();
                d.show();
            }
        });
    }
}

Output