Android for Ninjas

I will show you how get Android API version by code. You can use this comparation.  if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) { // Example compare with Android Oreo  } References. https://stackoverflow.com/questions/3423754/retrieving-android-api-version-programmatically https://developer.android.com/training/notify-user/channels#java https://developer.android.com/reference/android/os/Build.VERSION

How Activity works  This diagram show how to Activity lifecycle works.  onCreate() You must implement this callback, which fires when the system first creates the activity.  Bibliographic reference https://developer.android.com/guide/components/activities/activity-lifecycle

How to add a image into menu from url I will show how to add a image from url like a Drawable object  You will need this references. In this case we will use this method  import android.graphics.drawable.Drawable; import android.graphics.drawable.BitmapDrawable; import java.net.URL; import java.net.HttpURLConnection; import android.graphics.BitmapFactory.Options; import android.graphics.Bitmap; import java.io.ByteArrayOutputStream; You could be need add this policy into main activity. StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();         StrictMode.setThreadPolicy(policy); You can use this method into your class     public static Drawable getImageByteUrl(Context context,String url)     {         Drawable image = null;         try         {             URL imageUrl = new URL(url);             HttpURLConnection conn = (HttpURLConnection) imageUrl.openConnection();             conn.connect();          

Android version history This is a history version of Android Updated 04-March-2019