Master Android from first principles and begin the journey toward your own successful Android applications!
Dear Reader,
First, welcome to the world of Android! We’re entering a new era of mobile application development, one marked by open platforms and open source, to take ‘walled gardens’ and make them green houses for any and all to participate in. Android is relatively easy for developers, and I believe that this innovation will help generate a large ecosystem of developers and consumers within a very short time. This means that budding developers such as yourself will have many opportunities to design and build your own applications and you’ll have a huge and hungry customer base.
Second, welcome to the book! Its purpose is to start you on your way with building Android applications, and to help you master the learning curve. Android is already a rich framework, comparable in many ways to the richness Android of desktop Java environments. This means that there is a lot of cool stuff for you to pick up along your journey in order to create the slickest, most useful apps Android you can imagine.
The source code for the code samples in this book is all available from the Apress site, so you can stay as hands-on and practical as you like while I introduce you to the core of Android, and invite you to experiment with the various classes and APIs we’ll be looking at. By the time you’ve finished this book, you’ll be creating your own Android applications and asking yourself what your next great application will be…!
Enjoy!
Mark Murphy
Arrays
Arrays
Array resources are designed to hold lists of simple strings, such as a list of honorifics (Mr., Mrs., Ms., Dr., etc.).
In the resource file, you need one string-array element per array, with a name attribute for the unique name you are giving the array. Then, add one or more child item elements, each of which have a single text element with the value for that entry in the array:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<string-array name="cities">
<item>Philadelphia</item>
<item>Pittsburgh</item>
<item>Allentown/Bethlehem</item>
<item>Erie</item>
<item>Reading</item>
<item>Scranton</item>
<item>Lancaster</item>
<item>Altoona</item>
<item>Harrisburg</item>
</string-array>
<string-array name="airport_codes">
<item>PHL</item>
<item>PIT</item>
<item>ABE</item>
<item>ERI</item>
<item>RDG</item>
<item>AVP</item>
<item>LNS</item>
<item>AOO</item>
<item>MDT</item>
</string-array>
</resources>
From your Java code, you can then use Resources.getStringArray() to get a String[] of the items in the list. The parameter to getStringArray() is your unique name for the array, prefixed with R.array. (e.g., Resources.getStringArray(R.array.honorifics)).
