Intro to Android Development

Ben Lafreniere

Getting up and running• Don’t use the VM!• http://developer.android.com/resources/tutor

ials/hello-world.html• Steps:– Install Eclipse– Install the Android Development Tools (ADT)

plugin– Install the Android SDK (may be optional)– Create an emulator– Hello world!

Download and Install Eclipse• Eclipse has many versions!• Go with Eclipse Classic

(32- or 64-bit depending on your system)• http://www.eclipse.org/downloads

Install ADT plugin

• http://developer.android.com/sdk/eclipse-adt.html#installing

Download and Install the Android SDK

• http://developer.android.com/sdk/index.html

Use SDK Manager to install APIs

• Why so many SDK versions?– Android is a UI toolkit being incrementally

developed before our eyes

• Install and use Android 2.3.3 SDK (API 10)– Because these are the phones we’ll be marking on

Video walkthrough

• anddev_installing.avi

Creating an emulator

• Not all developers have android devices– So we emulate one!

• Video– anddev_create_emu.avi

Developing with the Emulator

• Emulator takes a long time to boot up– Enabling the ‘Snapshot’ option speeds things up

by saving the emulator’s state when it’s closed, and restoring it when it’s started again

• You can keep the emulator open between runs

• Don’t develop on the VM!(the emulator will run way too slow)

Android Programming

Creating an Android project• http://developer.android.com/resources/tutorials/hello-

world.html

Hello World!

• HelloAndroidActivity.java

Android App Anatomy – Classes

• Activity – A single screen of the application

• View – The superclass for widgets(the UI is made up of a tree of View objects)

• Intent – An action that must be performed

Activities

• A single, focused thing that the user can do• Should use an Activity for each screen of the

application• Activities must be declared in the Manifest file

Views

• Superclass of all Android widgets(similar to java.awt.Component in Swing)

Views

• Superclass of all Android widgets(similar to the Component class from Swing)

Intents• Abstract description of an action that the user

wants to perform (e.g. open a webpage,share a picture)

• Used to transition betweenActivities

• Includes the intended action,and may include data

Code Examples• HelloAndroid – One Activity, One TextView,

very simple

• FormExample – Two Activities, using an Intent to start a second Activity

• DataPassExample – Builds on FormExample, using Intents to pass data between Activities

Much more

• Using XML layouts to separate presentation from logic

• Using strings.xml in lieu of hard-coded strings

• Saving the application’s state when an activity is paused

Useful references• Android Developers

http://developer.android.com• Tutorials section

http://developer.android.com/resources/browser.html?tag=tutorial

• Notebook tutorial (detailed multi-Activity example)http://developer.android.com/resources/tutorials/notepad/index.html

• Common taskshttp://developer.android.com/resources/faq/commontasks.html