Hello World Program in Android

Simple Hello World Program in Android

Step1: Open Eclipse

Step2 : Specify your Work Space

Step3: Now Go to File => Project => Android Project =>Next

Step4:  Give Some Project Name(Here I am Giving HelloWorld)

Step5: Choose Your Target SDK(Here I am Taking Android 4.0.3. You can choose  any one 2.2 or 2.3 like that).

Step 6: After choosing Target SDK,Click on NEXT.

           It will ask Package name,activity name(Class name).

           For package you need to specify like that (android.hello world or anyname.name).If you not specify “ . “, it will show error.Here I am taking package “test.helloworld”.

          Activity name(Class name) taking as a “HelloWorldActivity”.

        Then Click on Finish.

Step7:  Open Negivator in Your eclipse(Window =>Show View => Nevigator

       Now See your Activity File, Layout file.

Step8: Open all the files that I marked.

            Go 2 main.xml. See Here we have taken TextView that means output will show in text view. See bellow how it would look like.

Step9:The question will arises  How it is showing “Hello World,Hello World Activity”.

<TextView

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:text="@string/hello" />

See here android:text ,we are calling @string/hello. This means it calling to string.xml(res/values).

Open string.xml.

<string name="hello">Hello World, HelloWorldActivity!</string>

    <string name="app_name">HelloWorld</string>

Here we are giving string name “hello” that is calling main.xml. So the output will be “Hello World, HelloWorldActivity!”.

Step10:

Xml is basically used for designing the activity. Now this xml file will call in Java File.

Go To “HelloWorldActivity.java” class(src/test/helloworld).

public class HelloWorldActivity extends Activity

{

    /** Called when the activity is first created. */

    @Override

    public void onCreate(Bundle savedInstanceState)

    {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);

    }

}

See here HelloWorldActivity class extending Activity.For developing any mobile application we need to inherit the methods from Activity.

Observe in “setContentView(R.layout.main);”, here it is calling that xml file.

Step11: (EXECUTION)

Go to Run=> Click on Run => Choose Android Application => Ok

It will take some time to load your activity.

Result: