Interface for accessing and modifying preference data returned by  getSharedPreferences(String, int) . For any particular set of preferences, there is a single instance of this class that all clients share. Modifications to the preferences must go through an  SharedPreferences.Editor  object to ensure the preference values remain in a consistent state and control when they are committed to storage. Objects that are returned from the various  get  methods must be treated as immutable by the application. MainActivity.java import android.content.Intent; import android.content.SharedPreferences; import android.os.Bundle; import android.support.v7.app.AppCompatActivity; import android.view.View; import android.widget.Button; import android.widget.EditText; import android.widget.Toast; public class MainActivity extends AppCompatActivity { EditText user, pass; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState);

ListView  is a view group that displays a list of scrollable items. The list items are automatically inserted to the list using an  Adapter  that pulls content from a source such as an array or database query and converts each item result into a view that's placed into the list. For an introduction to how you can dynamically insert views using an adapter, read  Building Layouts with an Adapter . list.xml < RelativeLayout xmlns: android = "http://schemas.android.com/apk/res/android"   xmlns: tools = "http://schemas.android.com/tools"  android :layout_width= "match_parent"   android :layout_height= "match_parent"  android :paddingLeft= "@dimen/activity_horizontal_margin"   android :paddingRight= "@dimen/activity_horizontal_margin"   android :paddingTop= "@dimen/activity_vertical_margin"   android :paddingBottom= "@dimen/activity_vertical

A dialog is a small window that prompts the user to make a decision or enter additional information. A dialog does not fill the screen and is normally used for modal events that require users to take an action before they can proceed. MainActivity.xml <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:tools="http://schemas.android.com/tools"     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=".MainActivity">     <Button         android:id="@+id/button"         android:layout_width="wrap_content"         androi

A  splash screen  is a graphical control element consisting of window containing an image, a logo and the current version of the software. A  splash screen  usually appears while a game or program is launching. import android.os.Bundle; import android.os.Handler; import android.app.Activity; import android.content.Intent; import android.view.Menu; public class MainSplashScreen extends Activity {      @Override      protected void onCreate(Bundle savedInstanceState) {          super .onCreate(savedInstanceState);          setContentView(R.layout.main_splash_screen);            // METHOD 1                         /****** Create Thread that will sleep for 5 seconds *************/                   Thread background = new Thread() {              public void run() {                                   try {                      // Thread will sleep for 5 seconds                      sleep( 5 * 1000 );