How to handle "Up" button?

Question

How to handle "Up" button (SDK version 11+)? I am referring to the one at the top of screen, that holds the application icon.

In Android Design articles it was named as "Up button", but I didn't found it (or similar) in KeyEvent fields.

Answer 1

Implement onOptionsItemSelected() and watch for android.R.id.home "menu" events, as is described in the documentation.

@Override public boolean onOptionsItemSelected(MenuItem item) {     switch (item.getItemId()) {         case android.R.id.home:             // do something useful             return(true);     }      return(super.onOptionsItemSelected(item)); } 

Answer 2

First change your AndroidManifest.xml file to have a parent activity declared. Eg

    <activity android:name=".theory"               android:parentActivityName=".MainActivity"         android:label="@string/theory"         />     <activity android:name=".experimental"               android:parentActivityName=".MainActivity"         android:label="@string/exp"         /> 

Do this for all the activities other than the MainActivity. Note the parentActivityName xml code

Then go to the respective java files and add the following code

    ActionBar ab = getSupportActionBar();     ab.setDisplayHomeAsUpEnabled(true); 

You have you up button enabled now.