CPET 565 Mobile Computing Systems CPET/ITC 499 Mobile Computing. Lab & Demo 2 (Part 1-2) Hello-Goodbye App Tutorial

Transcription

1 CPET 565 Mobile Computing Systems CPET/ITC 499 Mobile Computing Reference Lab & Demo 2 (Part 1-2) Tutorial Android Programming Concepts, by Trish Cornez and Richard Cornez, pubslihed by Jones & Barlett Learning, pp Android Developer API Guides, Paul I-Hai Lin, Professor Spring 2016 A Specialty Course Purdue University M.S. Technology Graduate Program Dept. of Computer, Electrical and Information Technology Purdue University Fort Wayne Campus 1 Objectives Learn to use Android Studio (Integrated Development Environment) Build your Second app for Android-based smartphone which will respond to the push button to display two messages Procedure A Prelab Study the basic terms of IDE and Android APIs 1) Major components of an App: manifests - AndroidManifest.xml java res (drawable, layout, menu, values) Gradle Scripts 2 1

2 1) Major components of an App: manifests (AndroidManifest.xml), Java res (drawable, layout, menu, values) res/layout/activity_my.xml res/layout/content_my.xml holds Hello World! message res/menu/menu_my.xml mipmap/ic_launcher.png/ic_launcher.png (hdpi) ic_launcher.png (xxhdpi) res/values/color.xml res/values/dimens.xml res/values/string.xml Res/values/styles.xml 3 A Prelab Study the basic terms of IDE and Android APIs 2) Activity class, Activity.html One application is made up of one or more Activities Banking App example: Log-in-account Activity, Accountoverview Activity, etc Each Activity has A visual UI (layout) to the user, and a Java source code (some behavior functions) An application may contain multiple activities Main activity (the one that launched for the first time when the application is executed) Methods: oncreate(), onstart(), onrestart(), onresume(), onpause(), onstop(), ondestroy() 4 2

3 B Prelab App Requirements and Design 1) App s requirements Launch icons Color, background, fonts, layout, etc. 2) Output: Texts, graphic images, etc. 3) UI interaction Button (tapping) 5 C Creating HelloGoodbye Project 1) Configure your new project Application name: Hello Goodbye Company Domain Project location 2) Select the form factors your app will run on Phone and Tablet, Minimum SDK 3) Add an activity to Mobile Blank Activity 4) Customize the Activity Activity Name - use default Layout Name use default Title use default Menu Resource Name use default 6 3

4 C Creating a new Project Default launch icon (Android robot) Examine the following XML files o AndroidManifest.xml Adding and Editing Application Resources Go to Jones & Bartlett Learning web site, og/ / Redeem your access code using your 10-digit code from your book Download chapter 1 related png files (xhdpi densities) 7 Drag and drop (or copy & paste) the following png files (both xhdpi and xxhdpi versions) from the textbook resource to the drawable folder o Background background.png o greetingimage.png o exclamation-btn.png o Ic_launcher.png 8 4

5 Edit the res/values/string.xml (name/value pairs) as shown on the screen shot below. 9 Edit a new Values XML file Right click values => New => XML => Values XML files Or just revise the exiting color.xml 10 5

6 Constructing the User Interface of the App Click the activity_main.xml from the layout folder to see the project window as shown on the right. 11 Select background file from the Drawable foler, click OK 12 6

7 Select RelativeLayout in the Component Tree panel of the Layout Editor. Click on three-dot button on the right of background to see Resources window as shown below. Select background file from the Drawable folder, click OK 13 The green colored backbround image file is now added to the app. 14 7

8 Return to the Design mode of the Layout Editor: res/layout/content_main.xml Delete the existing <TextView> element <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="hello World!" /> Verify Hello World! has been removed 15 Summary Q/A? 16 8