Android program to implement AlertDialog

AlertDialog in Android is a subclass of Dialog class. AlertDialog is used to display message with yes/no buttons.

AlertDialog contains a title section, content section and action buttons.

To make an alert dialog, you need to make an object of AlertDialogBuilder.

Syntax is given below:-

AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(this)

In the code given below, we will be having two action buttons yes/no to close the android application.

Steps to create the application:-

Open Android Studio and create a new Android application and name it as “AlertDialog” and company domain as codedost so your package will be automatically set.
Open an Empty Activity and name it as MainActivity.
Copy the contents of res/layout/activity_main.xml file.
Run the application to launch Android emulator or you can run it on your mobile also(which is way faster).

XML File(res/layout/activity_main.xml):

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="codeost.alertdialog.MainActivity">


    <Button
        android:text="Show AlertDialog Box"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true"
        android:layout_centerHorizontal="true"
        android:id="@+id/button" />
</RelativeLayout>

MainActivity.java

package codedost.alertdialog;

import android.content.DialogInterface;
import android.preference.DialogPreference;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity {

    Button b1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        b1=(Button) findViewById(R.id.button);

        b1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                AlertDialog.Builder builder=new AlertDialog.Builder(MainActivity.this);
                builder.setMessage("Do you want to closs the application?").setCancelable(false).setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        finish();
                    }
                })
                        .setNegativeButton("No", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                dialog.cancel();
                            }
                        });

                AlertDialog alertDialog=builder.create();
                alertDialog.setTitle("AlertDialogBox");
                alertDialog.show();
            }
        });
    }
}

CODEDOST

Android program to implement AlertDialog