This document summarizes the major versions of the Android SDK from 1.0 to 6.0, listing the corresponding API level, year of release, and notable new features for each version.

3. Version(s) API Level(s) Year(s) SDK Notes / New Features
1.0-1.1 1-2 2008-2009 First releases, Android Market
1.5 “Cupcake” 3 2009 3rd party keyboards, Widgets
1.6 “Donut” 4 2009 Speech engine
2.0-2.1 “Éclair” 5-7 2009 HTML5, Bluetooth API, Multi-touch SDK
2.2 “Froyo” 8 2010 Performance, JIT,V8 engine, push notifications, Hi-DPI
2.3 “Gingerbread” 9-10 2010-2011 New UI,WXGA,VoIP, NFC, multiple cameras,
concurrent GC, more sensors supported
3.0-3.2 “Honeycomb” 11-13 2011 Holo UI, tablets only, System bar, Action bar, two-pane
UI, multi-core processors, external keyboards/mice

4. Version(s) API Level(s) Year(s) SDK Notes / New Features
4.0 “Ice Cream Sandwich” 14-15 2011 Brings 3.x features to phones, speech to text
4.1-4.3 “Jelly Bean” 16-18 2012-2013 “Project Butter”, expandable notifications, 7”
tablet UI, geofencing, native emojis
4.4 “KitKat” 19 2013 Low RAM device support, cleaner Holo UI,
immersive mode apps,WebView uses
Chromium, Storage Access Framework, UI
transition framework
4.4W “KitKat” 20 2013 Wearable extensions (smartwatches)
5.0-5.1 “Lollipop” 21-22 2014-2015 Android Runtime (ART), 64-bit support, vector
drawables, Material Design,WebView updated
through Play Store
6.0 “Marshmallow” 23 2015 Data backup/restore for apps, in-app
permission checks

16. C# Keyword / Usage Java Keyword / Usage
bool boolean
string <none> (use String type)
namespace (block scoped) package (file scoped)
using (a namespace or “static”) import (a package, class, or wildcard)
base super
MyClass : MyBaseClass, IMyInterface MyClass extends MyBaseClass implements MyInterface
const (field) static final
readonly final
sealed final
<none> (variable used in lambda) final (variable used in anonymous inner class)
is instanceof
lock synchronized
foreach (Type item in collection) for (Type item : collection)
typeof(MyClass) MyClass.class

21. .NETType JavaType
IEnumerable, IEnumerable<T> Iterable<T>
IEnumerator, IEnumerator<T> Iterator<T>
IList, IList<T> List<E>
List<T> ArrayList<E> implements List<E>
IDictionary<TKey,TValue> Map<K,V>
Dictionary<TKey,TValue> HashMap<K,V> implements Map<K,V>
KeyValuePair<TKey,TValue> Map.Entry<K,V>
ICollection<T> Collection<E>
ISet<T> Set<E>
HashSet<T> HashSet<E> implements Set<E>

22. .NETType JavaType(s)
System.Guid java.util.UUID
System.DateTime java.util.Date
System.IDisposable java.io.Closeable
System.ISerializable java.io.Serializable
System.IO.Stream java.io.InputStream, java.io.OutputStream
System.Type java.lang.Class<T>
System.Uri java.net.URI, java.net.URL, android.net.Uri
System.Text.RegularExpressions.Regex java.util.regex.Matcher, java.util.regex.Pattern

24. Notice: final keyword, MainActivity.this, and thatView.OnClickListener is an interface

28. EmailActivity
EmailListFragment
EmailActivity
EmailListFragment EmailMessageFragment
Phone UI Tablet UI
EmailMessageFragment

32. http://developer.android.com/guide/topics/ui/menus.html

37. http://developer.android.com/training/basics/activity-lifecycle/starting.html

38. Lifetime First Call Final Call
Entire Lifetime onCreate onDestroy
Visible Lifetime onStart onStop
Foreground Lifetime onResume onPause

39. Lifecycle Method Next Method Common Usage
onCreate onStart Set up activity’s view, get view references
(findViewById), restore instance state
onStart onResume or onStop (rare)
onRestart onStart (rare)
onResume onPause Start any timers or CPU-consuming tasks, refresh UI
elements, play audio/video
onPause onResume or onStop Pause any timers or CPU-consuming tasks, pause
audio/video
onStop onRestart or onDestroy (rare) Clean up your activity
onDestroy nothing (rare) Clean up your activity
* onSaveInstanceState Save instance state (duh)
* onRestoreInstanceState (rare) Restore instance state (duh)
* Not part of previous diagram

48. Intent Action (public static final String) Example Usage
Intent.ACTION_VIEW Open URL
Intent.ACTION_ATTACH_DATA Attach photo to a contact
Intent.ACTION_EDIT Edit a calendar entry
Intent.ACTION_PICK Pick a file from a directory
Intent.ACTION_DIAL Call a number
Intent.ACTION_SEND Share something (system share chooser)
Intent.ACTION_SEARCH Perform a system search
Intent.ACTION_WEB_SEARCH Perform a web search
MediaStore.ACTION_IMAGE_CAPTURE Take a photo with the camera (default app)
MediaStore.ACTION_VIDEO_CAPTURE Record a video with the camera (default app)

57. Permission Group Permissions
CALENDAR READ_CALENDAR,WRITE_CALENDAR
CAMERA CAMERA
CONTACTS READ_CONTACTS,WRITE_CONTACTS, GET_ACCOUNTS
LOCATION ACCESS_FINE_LOCATION,ACCESS_COARSE_LOCATION
MICROPHONE RECORD_AUDIO
PHONE READ_PHONE_STATE, CALL_PHONE, READ_CALL_LOG,WRITE_CALL_LOG,
ADD_VOICEMAIL,USE_SIP, PROCESS_OUTGOING_CALLS
SENSORS BODY_SENSORS
SMS SEND_SMS, RECEIVE_SMS, READ_SMS, RECEIVE_WAP_PUSH, RECEIVE_MMS
STORAGE READ_EXTERNAL_STORAGE,WRITE_EXTERNAL_STORAGE

59. Directive Example Description
compileSdkVersion compileSdkVersion 23 Which API level this is compiled against
buildToolsVersion buildToolsVersion “21.1.2” Android BuildTools installed version
applicationId applicationId “com.feature23.hello” The unique app ID, used by the OS
minSdkVersion minSdkVersion 19 App won’t run on devices below this
targetSdkVersion targetSdkVersion 23 Which API level this app is tested
against
versionCode versionCode 2 Integer version code, must increment
each release, no decimal places
versionName versionName “1.01” User-friendly version number
compile compile
'com.google.code.gson:gson:2.4'
Add a Maven dependency
compile files('libs/coollection-
0.2.0.jar')
Add a jar dependency