12.2 The Activity and Fragment Classes

With few exceptions, activities and fragments in an application are created as subclasses of the Android AppCompatActivity class and Fragment classes respectively.

Consider, for example, the simple AndroidSample project created in “Creating an Example Android App in Android Studio”. Load this project into the Android Studio environment and locate the MainActivity.java file (located in app -> java -> com.<your domain>.androidsample). Having located the file, double-click on it to load it into the editor where it should read as follows:

package com.ebookfrenzy.androidsample;

 

import android.os.Bundle;

 

import com.google.android.material.floatingactionbutton.FloatingActionButton;

import com.google.android.material.snackbar.Snackbar;

 

import androidx.appcompat.app.AppCompatActivity;

import androidx.appcompat.widget.Toolbar;

 

import android.view.View;

import android...