Building Your First App

Welcome to Android application development!

This class teaches you how to build your first Android app. You’ll learn how to create an Android project and run a debuggable version of the app. You'll also learn some fundamentals of Android app design, including how to build a simple user interface and handle user input..

Hello Android Example

You need to follow the 3 steps mentioned above for creating the Hello android application.

1) Create the New Android project

For creating the new android project:

1) Select File > New > Project...

2) Select the android project and click next

3) Fill the Details in this dialog box and click finish

Now an android project have been created. You can explore the android project and see the simple program, it looks like this:

Main Activity :

package com.example.helloworld;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.MenuItem;
import android.support.v4.app.NavUtils;

public class MainActivity extends Activity {

   @Override
   public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
   }
   
   @Override
   public boolean onCreateOptionsMenu(Menu menu) {
      getMenuInflater().inflate(R.menu.activity_main, menu);
      return true;
   }
}

Manifest.xml File :

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
   package="com.example.helloworld"
   android:versionCode="1"
   android:versionName="1.0" >
   
   <uses-sdk
      android:minSdkVersion="8"
      android:targetSdkVersion="22" />
   
   <application
       android:icon="@drawable/ic_launcher"
       android:label="@string/app_name"
       android:theme="@style/AppTheme" >
       
       <activity
          android:name=".MainActivity"
          android:label="@string/title_activity_main" >
       
          <intent-filter>
             <action android:name="android.intent.action.MAIN" />
             <category android:name="android.intent.category.LAUNCHER"/>
          </intent-filter>
       
       </activity>
       
   </application>
</manifest>

Run The Application:

To run the android application: Right click on your project > Run As.. > Android Application

The android emulator might take 2 or 3 minutes to boot. So please have patience. After booting the emulator, the eclipse plugin installs the application and launches the activity. You will see something like this: