| Android Name | Version | Year of Release |
| Android 1.5 | Android Cupcake | 2009 |
| 1.6 | Donut | 2009 |
| 2.0-2.1 | Eclair | 2009 |
| 2.2 – 2.2.3 | Froyo | 2010 |
| 2.3 – 2.3.7 | Gingerbread | 2010 |
| 3.0 – 3.2.6 | Honeycomb | 2011 |
| 4.0 – 4.0.4 | Ice Cream Sandwich | 2011 |
| 4.1 – 4.3.1 | Jelly Bean | 2012 |
| 4.4 – 4.4.4 | KitKat | 2013 |
| 5.0 – 5.1.1 | Lollipop | 2014 |
| 6.0 – 6.0.1 | Marshmallow | 2015 |
| 7.0 – 7.1.2 | Nougat | 2016 |
| 8.0 – 8.1 | Oreo | 2017 |
| 9.0 | Pie | 2018 |
| 10.0 | Quince Tart | September 3, 2019 |
| 11.0 | Red Velvet Cake | September 8, 2020 |
| 12.0 | Snow Cone | October 4, 2021 |
.apk extension and has all the application code, resource files, certificates, and other files, compressed in it. ndroid.app.Activity class i.e :onCreate() : In this state, the activity is created.onStart() : This callback method is called when the activity becomes visible to the user.onResume() : The activity is in the foreground and the user can interact with it.onPause() : Activity is partially obscured by another activity. Other activity that’s in the foreground is semi-transparent.onStop() : The activity is completely hidden and not visible to the user.onDestroy() : Activity is destroyed and removed from the memory.context.startActivity() : To start an activitycontext.startService() : To start a servicecontext.sendBroadcast() : To deliver a broadcastPublic class MyActivity extends Activity
{
}
Public class MainService extends Service
{
}
setOrientation() is a method using which you can set a screen alignments. HORIZONTAL and VERTICAL are two values that can be set in the setOrientation() method. Whenever there is a change in the display orientation i.e. from Horizontal to Vertical or vice versa then onCreate() method of the Activity gets fired.AndroidManifest.xml file.AndroidManifest.xml file in the root directory. It contains information about your app and provides the same to the Android system.onCreate() is called when the Activity is created; that is, it is launched or started. (Additionally, this triggers when the orientation is changed.) It is called again when the process is killed, then returned to.onStart() called following onCreate() at startup. Additionally, it is also called when the app is navigated back to after onStop() (and following onRestart()), which occurs after the Activity is no longer visible (which is during the time that "the user can see the activity on-screen, though it may not be in the foreground and interacting with the user").onTrimMemory(int level) is used when the operating system has determined that a process to trim unneeded memory from its subprocess. Intent i = new Intent(ACTION_VIEW,Uri.parse("https://www.freetimelearning.com"));
startActivity(i);
getIntent().getExtras() methods.Intent i = new Intent(this, Activitytwo.class); #ActivityTwo is the target component
i.putExtra("Value1","This is ActivityTwo");
i.putExtra("Value2","This Value two for ActivityTwo");
startactivity(i);
Toast.makeText(ProjectActivity.this, "Your message here", Toast.LENGTH_LONG).show();public class MyReceiver extends BroadcastReceiver {
Public void onReceive(context,intent){}
}
<WebView> element to your XML layout file. src : contains the .java source files for your project.gen : contains the .R file, a compiler-generated file that references all the resources found in your project.bin : contains the Android package files .apk built by the ADT during the build process and everything else needed to run an Android application.res/drawable-hdpi : this is a directory for drawable objects that are designed for high-density screens.res/layout : this is a directory for files that define your app’s user interface.res/values : this is a directory for other various XML files that contain a collection of resources, such as strings and colors definitions.AndroidManifest.xml : this is the manifest file which describes the fundamental characteristics of the app and defines each of its components.registerReceiver() for that action — even with a null BroadcastReceiver — you get the Intent that was last broadcast for that action. Hence, you can use this to find the state of the battery without necessarily registering for all future state changes in the battery. Entire Lifetime : In this key loop, the activity happens between the onCreate and onDestroy.Visible Lifetime : In this key loop, the activity happens between onStart and onStop.Foreground Lifetime : In this key loop, the activity happens between onResume and onPause.