How to add an actionbar in android studio for beginners?

Question

I want to build my own app and i want to add an action bar to it.In my main layout i want an action bar with my app name only.In my other layouts/pages i want my page name and a back navigating symbol which navigates back to the previous page.Can anybody tell me how to do this and also can somebody tell me about the default actionbar in android what it does and what do i do with it.

Answer 1

STEP 1 : build.gradle (Application Level)

dependencies {
    compile 'com.android.support:appcompat-v7:23.3.0'
}

STEP 2 : AndroidManifest.xml

<application
....
android:theme="@style/Theme.AppCompat.Light.DarkActionBar"/>

STEP 3 : In your activity

public class main extends AppCompatActivity
{
    ....
    @Override
    protected void onCreate(Bundle savedInstanceState) {

        ...

        getSupportActionBar().setTitle("Your Activity Title"); // for set actionbar title
        getSupportActionBar().setDisplayHomeAsUpEnabled(true); // for add back arrow in action bar
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
    // TODO Auto-generated method stub
    int id = item.getItemId();
    if (id == android.R.id.home) {
        finish();
    }
    return super.onOptionsItemSelected(item);
}