This section includes samples for:

Activity

Hello World
Demonstrates a basic screen activity.
Code:
HelloWorld.java
Layout:
hello_world.xml
Save & Restore State
Demonstrates how an activity should save state when it is paused.
Persistent State
Demonstrates how you can save and restore preferences, which are stored even after the user closes the application.
Receive Result
Demonstrates how an activity screen can return a result to the activity that opened it.
Forwarding
Demonstrates opening a new activity and removing the current activity from the history stack, so that when the user later presses BACK they will not see the intermediate activity.
Redirection
Demonstrates how to save data to preferences and use it to determine which activity to open next.
Translucent
Demonstrates how to make an activity with a transparent background.
TranslucentBlur
Demonstrates how to make an activity with a transparent background with a special effect (blur).
Dialog Activity
An Activity that sets its theme to android:style/Theme.Dialog so that it looks like a Dialog.
Custom Title
An Activity that places a custom UI in its title.
Animation
Demonstrates how to use custom animations when moving between activities.
Activity Recreate
Demonstrates how an Activity can cause itself to be recreated.
Screen Orientation
Demonstrates the different screen orientations an Activity can request.
Soft Input Modes
Demonstrates how different soft input modes set in an Activity's window impacts how it adjusts to accommodate an IME.
Intent Activity Flags
Demonstrates various uses of Intent flags to modify an application task's activity stack in common ways.
Reorder on Launch
Demonstrates how the activities in a task can be reordered. UI flow goes through the activities ReorderOnLaunch, ReorderTwo, ReorderThree, and ReorderFour.
Wallpaper Activity
An Activity that uses android:style/Theme.Wallpaper to be displayed on top of the system wallpaper.

Fragment

Fragment Alert Dialog
Demonstrates how to use a DialogFragment to show and manage an AlertDialog.
Fragment Arguments
Demonstrates how a fragment can be initialized with arguments, supplying them either as an argument Bundle at runtime or XML attributes in a <fragment> tag.
Fragment Context Menu
Demonstrates how to display and respond to a context menu that is display from a fragment's view hierarchy.
Fragment Custom Animation
Demonstrates the use of a custom animation for pushing and popping fragments on the back stack.
Fragment Dialog
Demonstrates use of DialogFragment to show various types of dialogs.
Fragment Dialog or Activity
Demonstrates how the same Fragment implementation can be used to provide the UI for either an Activity or Dialog.
Fragment Hide Show
Demonstrates hiding and showing fragments.
Fragment Layout
Demonstrates use of the <fragment> tag to embed a Fragment in an Activity's content view layout, and making the layout change based on configuration to achieve different UI flows.
Fragment List Array
Demonstrates use of ListFragment to show the contents of a simple ArrayAdapter.
Fragment Menu
Demonstrates populating custom menu items from a Fragment.
Fragment Receive Result
Demonstrates starting a new Activity from a Fragment, and receiving a result back from it.
Fragment Retain Instance
Demonstrates a Fragment can be used to easily retain active state across an Activity's configuration change.
Fragment Stack
Demonstrates creating a stack of Fragment instances similar to the traditional stack of activities.
Fragment Tabs
Demonstrates implementing ActionBar tabs by switching between Fragments.

Action Bar

Action Bar Mechanics
Demonstrates the basics of the Action Bar and how it interoperates with the standard options menu. This demo is for informative purposes only; see Usage for an example of using the Action Bar in a more idiomatic manner.
Action Bar Tabs
Demonstrates the use of Action Bar tabs and how they interact with other action bar features. Also see the Fragment Tabs for a more complete example of how to switch between fragments.
Action Bar Usage
Demonstrates simple usage of the Action Bar, including a SearchView as an action item. The default Honeycomb theme includes the Action Bar by default and a menu resource is used to populate the menu data itself. If you'd like to see how these things work under the hood, see Mechanics.
Settings Action Provider
Shows how to implement an ActionProvider for launching the system settings that supplies a menu item with a specialized action view and handles standard menu item clicks in one place.
Share Action Provider
Shows how to use a ShareActionProvider to embed sharing functionality in your application via the streamlined sharing UI added in ICS.
Display Options
Shows how various Action Bar display option flags can be combined and their effects.

LoaderManager

Loader Cursor
Demonstrates use of LoaderManager to perform a query for a Cursor that populates a ListFragment.
Loader Custom
Demonstrates implementation and use of a custom Loader class. The custom class here "loads" the currently installed applications.
Loader Throttle
Complete end-to-end demonstration of a simple content provider that populates data in a list through a cursor loader. The UI allows the list to be populated with a series of items, showing how AsyncTaskLoader's throttling facility can be used to control how much a Loader is refreshed in this case.

Service

Local Service
Demonstrate the implementation of a service that runs in the same process as its client(s). Shows how those clients can either start/stop it with Context.startService and Context.stopService, or bind and call it with Context.bindService and Context.unindService. This also shows how you can simplify working with a service when you know it will only run in your own process. The client code for interacting with the service is in Local Service Activities.
Messenger Service
Demonstrates binding to a Service whose interface is implemented with the Messenger class. This is often an easier way to do remote communication with a Service than using a raw AIDL interface. The client code for interacting with the service is in Messenger Service Activities.
Remote Service Controller and Remove Service Binding
Demonstrates starting a service in a separate process, by assigning android:process=":remote" to the service in the AndroidManifest.xml file. Shows how those clients can either start/stop it with Context.startService and Context.stopService, or bind and call it with Context.bindService and Context.unindService. Binding is similar to the local service sample, but illustrates the additional work (defining aidl interfaces) needed to interact with a service in another process. Also shows how a service can publish multiple interfaces and implement callbacks to its clients.
Service Start Arguments
Demonstrates how you can use a Service as a job queue, where you submit jobs to it with Context.startService instead of binding to the service. Such a service automatically stops itself once all jobs have been processed. This can be a very convenient way to interact with a service when you do not need a result back from it.
Foreground Service
Shows how you can write a Service that runs in the foreground and works on both pre-2.0 and post-2.0 versions of the platform. This example will selectively use the new foreground APIs that were introduced in Android 2.0 if they are available.

Alarm

Alarm Controller
Demonstrates two ways you can schedule alarms: a one-shot alarm that will happen once at a given time, and a repeating alarm that will happen first at a given time and then continually trigger at regular intervals after that.
Code:
AlarmController.java
OneShotAlarm.java
RepeatingAlarm.java
Layout:
alarm_controller.xml
Alarm Service
Demonstrates how you can schedule an alarm that causes a service to be started. This is useful when you want to schedule alarms that initiate long-running operations, such as retrieving recent e-mails.
Code:
AlarmService.java
AlarmService_Service.java
Layout:
alarm_service.xml

Notification

NotifyWithText
Demonstrates popup notifications of varying length.
IncomingMessage
Demonstrates sending persistent and transient notifications, with a View object in the notification. It also demonstrated inflating a View object from an XML layout resource.
Status Bar Notifications
Demonstrates a variety of different notifications that can be posted in the status bar, and a standard way for handling them.
SearchInvoke
Demonstrates various ways in which activities can launch the Search UI.
SearchQueryResults
Demonstrates an activity that receives Search intents and handles them.
SearchSuggestionSampleProvider
Demonstrates how to configure and use the built-in "recent queries" suggestion provider.

Misc

Alert Dialog Samples
Demonstrates various styles of alert dialogs.
Device Admin Sample
Demonstration of the implementation of a simple device administrator and its use of the DevicePolicyManager.