Contents

• Overview
• ActionBarSherlock
• Navigation Tabs with the ActionBar
• TabHost Overview
• Creating a Tabbed UI with TabHost

Overview

Tabs are a popular user interface pattern in mobile applications because of their simplicity and usability. They provide a consistent, easy way to navigate between various screens in an application. Android has several API's for tabbed interfaces:

• TabHost – This is the original API for creating tabbed user interfaces. A TabHost widget is added to a layout and acts as a container for tabbed views. This API has since been deprecated and it's use is discouraged.

• ActionBar – This is part of a new set of API's that was introduced in Android 3.0 (API level 11) with goal of providing a consistent navigation and view-switching interface. It has been back ported to Android 2.2 (API level 8) with the Android Support Library v7.

• PagerTabStrip – Indicates the current, next, and previous pages of a ViewPager. ViewPager is available only via Android Support Library v4. For more information about PagerTabStrip, see ViewPager.

• Toolbar – Toolbar is a newer and more flexible action bar component that replaces ActionBar. Toolbar is available in Android 5.0 Lollipop or later, and it is also available for older versions of Android via the Android Support Library v7 NuGet package. Toolbar is currently the recommended action bar component to use in Android apps. For more information, see Toolbar.

These API's are visually very different, and are not compatible with each other. The following screen image shows TabHost and ActionBar side-by-side:

These incompatible API's exist because of significant UI changes since Android 3.0 (API level 11). One of these UI changes was the action bar design pattern, a pattern intended to provide easy access to navigation and key functionality in an application. The ActionBar API was introduced to support this pattern.

The ActionBar API is simpler and arguably provides a better user experience. It has been back ported to Android 2.2 and is the preferred choice for Xamarin.Android applications.

The TabHost API is compatible across all versions of Android but requires more effort to use and is not consistent with the current Android UI Guidelines. Developers are discouraged from using this API and should favour the newer ActionBar for their Xamarin.Android applications.

ActionBarSherlock

Before the ActionBar API's were backported to Android 2.2, developers who wanted the newer look and feel of the ActionBar API but could use a third-party library, ActionBarSherlock. ActionBarSherlock is an extension of the Android Support Library designed to backport the action bar design pattern to Android 2.x. When running on Android 3.0 or higher, ActionBarSherlock will automatically use the native ActionBar API provided by Android. Older versions of Android will use a custom implemention that will mimic the look and feel of the newer ActionBar API. The ActionBarSherlock component makes it easy to add ActionBarSherlock to a Xamarin.Android application.