The document provides an overview of key Android concepts including: - Android is an open source, Linux-based OS developed by Andy Rubin in 2004 and acquired by Google in 2005. - The Android SDK includes tools like Android Studio and the emulator for app development using Java. - Common widgets for building apps are provided by the Android.widget package like TextView and Button. - Intents allow activities to start other components and Services run in the background. - Notifications and databases allow displaying messages and storing app data.

2. Table of contentTable of content
 Android overview
 Android sdk overview
 Android.widget package
 Intent
 Multimedia
 Activity life cycle
 Android services
 Android notifications
 Databases

3. Android overviewAndroid overview
 It is an open source Linux-
based OS for handheld devices.
 Main objective was for digital
camera.
 Andy Rubin & co-member
developed Android in 2004 as
Android Inc.
Andy Rubin

4.  July 2005-Google acquired Android Inc.
 Sep 2008-version, Android 1.0 was released.
 HTC Dream: first phone in which android was installed and used.

5. Android SDK overviewAndroid SDK overview
 For the development of app an IDE is given: Android Studio,
Eclipse(SDK).
 SDK consist of class library, android debug tool, emulator etc.
 Emulator: is a virtual device used for testing our app which is also
called AVD(Android virtual Device).
 testing .apk
IDE AVD
Devi
ce

6.  Android apps are developed usually in java language using SDK.
 And till now various versions of android was launched which works on
different API levels.
 API: is an integer value; uniquely identifies the framework api revision
offered by android platform.

7. Android versionsAndroid versions
Versions API level Name
Android 1.0 1 Base / α
Android 1.1 2 Base_1_1 / β
Android 1.5 3 Cupcake
Android 1.6 4 Donut
Android 2.0 5 Eclair
Android 2.0.1 – 2.2.x 6,7,8 Éclair_0_1 - Froyo
Android 2.3 – 2.3.7 9,10 Gingerbread (Stable)
Android 3.0 – 3.2 11,12,13 Honeycomb (Failed)
Android 4.0 – 4.0.2 14 Ice-cream sandwich
Android 4.0.3 – 4.3 15,16,17,18 Ice-cream – jellybean
Android 4.4 – 5.0 19,20,21 Kitkat – lollipop

8. Android.widget packageAndroid.widget package
 Added in API level 1
 Contains UI elements to use on our screen/ Activity.
 Contains the basics controls(textview,button,textfields).
 It is the child of view group which is the parent of all the layouts.
ViewGroup
View View
ViewView View
ViewGroup

9. Android ActivityAndroid Activity
Android Activity
Xml filesXml files Java files
R.java Activity.java

10. Basic controls(android.widget)Basic controls(android.widget)
 Text View
 Edit Text
 Buttons
 Spinner
 Seek Bar
 Radio Buttons

11. Intent (android.content)Intent (android.content)
 It is an abstract description of an operation to be performed.
 (starting a new activity, starting a service etc).
 Syntax:
Intent i=new Intent(source, destinationClass);
startActivity(i);
 (Intent)
Activity 1 Activity 2

12. MultimediaMultimedia
 All the tasks like playing music, video, audio recording etc comes
under the category of android multimedia.
 All the multimedia file are to be put in a folder named as “raw” &
image in drawable folder.
 There are lots of predefined classes are given in android to access
various media operations(MediaPlayer, VideoView, MediaController
etc).
 Eg. playing a song

13. Activity life cycleActivity life cycle
 There are certain call back methods which are responsible for handling
the whole life cycle of any activity.
 onCreate()
 onStart()
 onResume()
 onPause()
 onRestart()
 onStop()
 onDestroy()

14. Activity
Launched
onCreate()
onStart()
onResume()
onPause()
onStop()
onRestart()
onDestroy()
Any interruption occurred
Activity is not visible
User navigates to
activity
Activity is finished

15. Android Services(android.app.Service)Android Services(android.app.Service)
 A service is an component that can perform long-running process in
the background and it does not provide any UI.
 There are two types of services:
 1.Started service: a service is “stared” when an application component
starts it by calling startServices().
 Once it started, run in the background infinitely.
 2.Bound service: a service is “bound” by calling bindService().
 Used on the client server.

16. Activity
started
onCreate()
Service
class
startService()
called
Returned output
onDestroy() if
onStartCommand()
stopService()
called
Service
class
Returned output

17. AndroidAndroid
Notification(android.app.Notification)Notification(android.app.Notification)
 It is a message that we can
display to the user outside of the
application.
 User can navigate the
notification by opening
notification drawer.
 There are some predefined
classes for achieving
notification:
 1.NotificationManager
//manages all the notification in
the app
 2.Notification //helps in
building notification.
 Methods:
 1.setsmallIcon(“path”);
 2.setTicker(“new msg rcvd”);
 3.setContentTitle(“ab@gml”);
 4.setContextText(“hello”);

18. Cont…Cont…
1.setsmallIcon(
“path”);
3.setContentTi
tle(“ab@gml”)
;
4.setContextTe
xt(“hello”);

19. Database(android.database.SQLite)Database(android.database.SQLite)
 All the database query are done in hard coded in android.
 There are two types of query:
 1. Updation type (execSQL() )
 2. selection type (rawQuery() )
 Ex:
 db.execSQL(“create table student(name varchar(10),…..)”);
 db. rawQuery(“select * from student here name=“Rajeev” ”);

20. Database
Updation
Type
Selection
Type
Update
Insert
Delete
Create
table
Select