Alert Dialog Box in Android

Hello friends,
Today we are going to learn about alert box in android. So into this application we can consist alert dialog box with set alert title, alert icons and alert message.so let's take an example.

alert_activity.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_centerHorizontal="true"
        android:layout_marginTop="20dp"
        android:onClick="alertDialog"
        android:text="Show Alert" />

</RelativeLayout>

MainActivity.java

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
    public void alertDialog(View view) {
        AlertDialog.Builder alertBuilder = new AlertDialog.Builder(this);
        alertBuilder.setTitle("TestApplication");
        alertBuilder.setIcon(R.mipmap.ic_launcher);
        alertBuilder.setCancelable(false);
        alertBuilder.setMessage("Take a decision");
        alertBuilder.setPositiveButton("Okay",
                new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface arg0, int arg1) {
                        Toast.makeText(MainActivity.this, "You clicked okay button", Toast.LENGTH_LONG).show();
                    }
                });
        alertBuilder.setNegativeButton("No", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                finish();
            }
        });
        AlertDialog alertDialog = alertBuilder.create();
        alertDialog.show();
    }
}



Output: