Transcript Basic Android Stuff

Basic, Basic, Basic Android
What are Packages?
• Page 346 in text
• Package statement goes before any import statements
• Indicates that the class declared in the file is part of the
specified package.
• Convention for naming packages
– Starts with Internet domain in reverse order
– edu.uta.davis.packagename;
• Compile the package class
– javac –d . FileName.java
• Import package into programs
– Import edu.uta.davis.packagename;
What is XML?
• Extensible Markup Language – set of rules for
encoding documents electronically
– Helps identify structures in documents
– Can invent own tags
• Not HTML
– HTML tags are fixed – displays data
– XML is a meta-language – transport and stores
data
<bookstore>
<book category="CHILDREN">
<title>Harry Potter</title>
<author>J K. Rowling</author>
<year>2005</year>
<price>29.99</price>
</book>
<book category="WEB">
<title>Learning XML</title>
<author>Erik T. Ray</author>
<year>2003</year>
<price>39.95</price>
</book>
</bookstore>
Main Components in Android
Application
• Activities – building block of user interface;
analogous to dialog box or window
• Content providers – way to store data on device that
is accessible by multiple applications
• Services – designed to run indefinitely, independent
of any activity (e.g., RSS feed, play back music
• Intents – systems messages that can notify
applications of various events from hardware state
changes to incoming data to application events
Other Features
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Storage
Network
Multimedia
Global positioning system
Phone services
What do you need?
• Eclipse 3.5 (Galileo)
• JDK 5 or JDK 6
• Android SDK starter package
– http://developer.android.com/sdk/index.html
• Android development tools
• Android Virtual Device
What does an Android Project Look
Like?
• Project contents are in an Android package file
(.apk)
• Root Directory
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AndroidManifest.xml
default.properties
assets
bin
gen
src
res
Root Directory (cont)
• AndroidManifest.xml – describes application being built and
which components are being supplied by the application
• default.properties – used by built script
• assets – holds other static files you want packaged with your
application
• bin – folder that holds compiled code
• gen – where Android’s tools will place source code they
generate
• src - hold Java source code for application
• res – holds resources that are packaged with the compiled
Java in the application (icons, GUI layouts, etc)
package com.example.helloandroid;
import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;
public class HelloAndroid extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
TextView tv = new TextView(this);
tv.setText("Hello Android");
setContentView(tv);
<?xml version="1.0" encoding="utf-8"?>
}
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
}
package="com.example.helloandroid"
android:versionCode="1"
android:versionName="1.0">
<application android:icon="@drawable/icon"
android:label="@string/app_name">
<activity android:name=".HelloAndroid"
android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category
android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>