android apps development for · 2015-05-08 · android apps development for mobile and tablet...

ANDROID APPS DEVELOPMENT FOR MOBILE AND TABLET DEVICE (LEVEL I)

Peter Lo

Lecture 1: Introduction to Android Development

Who am I?

Lo Chi Wing, Peter

� Email: [email protected]� Facebook: http://www.facebook.com/PeterLo111

X4-XT-CDP-0251-A @ Peter Lo 2015 2

Course Outline

3X4-XT-CDP-0251-A @ Peter Lo 2015

Lesson 1 Introduction to Android Development

Lesson 2 Android Programming Foundation

Lesson 3 Android Life Cycle and Permission

Lesson 4 Action Bar and Simple List

Lesson 5 Intent and Fragment

Lesson 6 Sensor and Storage

Where can you find the material?

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� Workshop Notes� http://www.Peter-Lo.com/Teaching/X4-XT-CDP-0251-A/

� Android Developer Official Site� http://developer.android.com/

� Microsoft DreamSpark� http://www.dreamspark.com

X4-XT-CDP-0251-A @ Peter Lo 2015

Mobile Phone Evolution


What is Android?

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� A Linux-based operating system for mobile devices.

� An open-source project and is distributed free of charge.

� Developed by the Open Handset Alliance and Google Inc.

� Supporting telephony, messaging, emailing, contact management, calendar, entertainment, multimedia experience, location services, mapping, social interaction, etc.


Android Family


Android 1.5(2009)

Android 1.6(2009)

Android 2.0/2.1(2009)

Android 2.2(2010)

Android 2.3(2010)

Android 3.0(2011)

Android 4.0(2012)

Android 4.4(2013)

Android 4.1(2012)

Platform Versions


Screen Sizes and Densities


Android Architecture


Development Process for Android Apps


Creating new Android Project


Application Name –name appears on device and title bar

Project Name – name for the Eclipse project

Package Name – Apps on a particular Android device must have unique packages

Minimum Required SDK –minimum Android API level required for the app

Target SDK –Android version that you want to use

Compile With – the platform version against which you will compile your app. (By default, set to the latest version of Android available in your SDK).

Theme – specifies the Android UI style to apply for your app.

Android Developer Tool (ADT)


Zone where the current layout is

rendered

Palette, where we

can choose different layouts

and for the layout design

Switch from the graphical editor to the XML text editor

Object properties

Tree View of hierarchical structure of layouts and

elements added to the

screen.File structure

Selector bar

Structure of a Typical Android App


Executable generated from compiled classes

Zipped archive file that will be shipped to android device

Zipped application resources

Source file with Activities, Services, Broadcast Receivers, and Content Providers

Provides access to resources (with unique ID) in App

Contain 2 auto generated files that should not be touched

Contains text files, database, and the sort

Contains file built by the ADT

Structure of a Typical Android App (cont.)


API that allows you to use the newest API while remaining backward compatible

The layout folder contains files that define the apps under interface• RelativeLayout• LinearLayout• GridLayout• FrameLayout

drawable folders store image you need at different resolutions

AndroidManifest defines: • App name• App icon• Activities used• Permission required for App• android.intent.action.MAIN define the entry point for App

The Manifest File

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� Before the Android system can start an application component, the system must know that the component exists by reading the application's AndroidManifest.xml file.


Apps must declare all its components in this file, which must be at the root of the application project directory.

SDK Manager


Simple Android App Program


package com.example.myfirstapp;

import android.os.Bundle;import android.app.Activity;import android.view.Menu;

public class MainActivity extends Activity {@Overrideprotected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);

}

@Overridepublic boolean onCreateOptionsMenu(Menu menu) {

// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.main, menu);return true;

}}

Define the Activity for output

Overriding an existing method

Apps are frequently shut down by the device. This lets you remember some info about the previous invocation. You should always call super.onCreate as first line of onCreate.

There is no need to type the import statements by hand. Just use the classes in your code, and when Eclipse marks the line as an error, click on the light bulb at the left, or hit [Ctrl] – [1], then choose to have Eclipse insert the import statements for you.

Comment, all statement after // will not execute

Running Apps

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� During the build process, your Android projects are compiled and packaged into an .apk file. It contains all of the information necessary to run your application on a device or emulator.

� If you are developing in Eclipse, the ADT plugin incrementally builds your project as you make changes to the source code. Eclipse outputs an .apk file automatically to the bin folder of the project, so you do not have to do anything extra to generate the .apk.


How to Testing or Running Apps?

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� On the Android Emulator:

� Deploy directly from Eclipse during development, do your normal testing here

� On an Android device:

� Deploy from your PC via USB

� Deploy from a Web site

� Deploy via email

� Deploy from the Android Market


Android Virtual Devices (AVD)

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� AVD is an Android Emulator configuration that lets you model an actual device by defining hardware and software options


Operation of AVD


Debugging

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� The Android SDK provides most of the tools that you need to debug your applications. � DDMS (Dalvik Debug Monitor Server)� adb (Android Debug Bridge)� JDWP debugger� Breakpoint� Log


Log Cat

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� The Android logging system provides a mechanism for collecting and viewing system debug output.

� Logs from various applications and portions of the system are collected in a series of circular buffers, which then can be viewed and filtered by the logcat command.


Logcat Level


Priority Meaning Description

V Verbose Lowest priority. Used for low level debugging. Print stuff like position of your character when you are debugging why the hell it's going off screen etc.

D Debug Messages that could be useful to determine where something went wrong. E.g. put a debug level message to each method beginning and end.

I Info These messages can be useful in production as well. Log important events in info level, e.g. Engine created

W Warning Something not quite right, but it's not a bug. E.g. you can't connect to Facebook to submit High score - not nice, but you can live with it.

E Error Log exceptions and errors that you will need to analyze later and solve.

F Fatal Fatal exception

S Silent Highest priority, on which nothing is ever printed

Dalvik Debug Monitor Service (DDMS)

� DDMS (Dalvik Debug Monitor Service) is a tool that supports many things

� Simulate incoming calls in emulator

� Set GPS locations in emulator

� See print statements and runtime errors

� Set locations and take screenshots of actual Android device


Break Point

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� To create a break point, just double click the vertical bar in Java source code

� When you run the application in debug mode, the emulator will pause and you will be able to examine your live code in this mode in the Eclipse debugger.


android apps development for · 2015-05-08 · android apps development for mobile and tablet...

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