Android
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Modified:

Overview

To start to understand an Android app, we will create the default app in Eclipse and examine the files created.

Starting at IUS

Copy C:\temp\.android   C:\Users\username\.android

Start Eclipse by opening
    C:\eclipse-jee-indigo-win32\eclipse and clicking

Select your workspace for saving files.

Set the Android SDK location by:

    Window | Preferences | Android | SDK Location: C:\Progra~1\Android\android-sdk

File | New | Project | Android

Name the project Test1
Check Build Target Android 3.2
Package name with at least one . in the name.
Click Finish.

To open the Project Explorer click the icon in the lower-left of the Eclipse window or Java in the upper-right.

Open Test1/src/edu.../Test1Activity.java

Click the upper-left bug and debug as Android Application.

After a bit of a wait and with luck, you'll see the emulator:

Drag the lock and you should see the results of Test1.

Two Java files define the code behind the app, two XML files define the view.

Click on Java in the upper-right corner to open the Package Explorer.

Window | New Window

Expand to display as below:

TestActivity1.java

Inherits from Activity, essentially the execution of the app, more detail at: http://developer.android.com/reference/android/app/Activity.html

setContentView(R.layout.main); sets the visible view to whatever is in XML file R.layout.main

R.java

Defines symbolic constants that corresponds to XML.

XML elements in strings.xml are constants in the class string.

main.xml

Default view definition.

Uses symbolic name android:text="@string/hello" to access string.xml and hello definition.

string.xml

Default string definition file.

hello definition.

Test1Activity.java

package edu.ius.rwisman.Test1;

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

public class Test1Activity extends Activity {
    /** Called when the activity is first created. */
    @Override 
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }
}

main.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" > <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="@string/hello" /> </LinearLayout>

strings.xml
<?xml version="1.0" encoding="utf-8"?> <resources> <string name="hello">Hello World, Test1Activity!</string> <string name="app_name">Test1</string> </resources>

R.java

/* AUTO-GENERATED FILE.  DO NOT MODIFY.
 *
 * This class was automatically generated by the
 * aapt tool from the resource data it found.  It
 * should not be modified by hand.
 */

package edu.ius.rwisman.Test1;

public final class R {
    public static final class attr {
    }
    public static final class drawable {
        public static final int icon=0x7f020000;
    }
    public static final class layout {
        public static final int main=0x7f030000;
    }
    public static final class string {
        public static final int app_name=0x7f040001;
        public static final int hello=0x7f040000;
    }
}

Add your name as part of the view.

Use either the graphical or XML file editor.

Android Start

Android
Start