Writing the Android First Application(Hello Android) Display on Emulator Screen.

Main.xml File:

  This file contains the layout in formation ...And Text (Hello Andriod)
<?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="Hello Andriod"
    />
</LinearLayout>

 ActivityClass(HellloAndriod .java)

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

}

AndriodManifest.xml 

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.surya"
      android:versionCode="1"
      android:versionName="1.0">
    <uses-sdk android:minSdkVersion="6" />

    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".HellloAndriod"
                  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>

All the Activity are configure in AndriodManifest.xml file , This file just like in our web application's Deployment Descriptor(web,xml)file..