FrameLayout fragment not visible Android

int n = 0;

try {
    n = Integer.parseInt("21"));
} catch(NumberFormatException e) {
   System.out.println("Could not parse " + e);
} 
// int to string
String s = String.valueOf(24);

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="//schemas.android.com/apk/res/android"
    package="cz.okhelp.admob"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk android:minSdkVersion="13"
        android:targetSdkVersion="16"/>

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    
   

    <application android:icon="@drawable/ic_launcher" android:label="@string/app_name">
       <meta-data 
        android:value="a14d932xxxxxxxx" 
        android:name="ADMOB_PUBLISHER_ID" />
        <activity android:name=".AdmobActivity"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

<activity android:name="com.google.ads.AdActivity"
 android:configChanges="keyboard|keyboardHidden|orientation|screenLayout|uiMode|screenSize|smallestScreenSize" />
</application>
</manifest>

		@Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
     			AdViw adView = new AdView(this, AdSize.BANNER, "a14d932xxxxxxxxx");//MY_AD_UNIT_ID
    			LinearLayout layout = (LinearLayout)findViewById(R.id.idReklamaLayout);
				// Add the adView to it
    			layout.addView(adView);
				// Initiate a generic request to load it with an ad
				AdRequest adRequest = new AdRequest();
    			//adRequest.setTesting(true);
    			adRequest.setGender(AdRequest.Gender.MALE);
    			adView.loadAd(adRequest);
    }

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="//schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >
    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello" />
<LinearLayout xmlns:android="//schemas.android.com/apk/res/android"
android:id="@+id/idReklamaLayout"
android:orientation="vertical"
android:gravity="center"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
/>
    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="3" />

</LinearLayout>

public class MainActivity extends Activity {
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(new SampleView(this));
	}

	private static class SampleView extends View {

		// CONSTRUCTOR
		public SampleView(Context context) {
			super(context);
			setFocusable(true);

		}
		@Override
		protected void onDraw(Canvas canvas) {
			Paint paint = new Paint();
			
			canvas.drawColor(Color.GREEN);
            
           Bitmap b = Bitmap.createBitmap(200, 200, Bitmap.Config.ALPHA_8);
           Canvas c = new Canvas(b);
           RectF rectF = new RectF();
           rectF.set(5,5,150,150);
           c.drawRoundRect(rectF, 10, 10, paint);
           
            paint.setColor(Color.RED);
           
           canvas.drawBitmap(b, 10,10, paint);
		}

	}
}

// Context instead Activity as a parameter
@Override
public void onAttach(Context context) {
    super.onAttach(context);

    Activity a;

    if (context instanceof Activity){
        a=(Activity) context;
    }

}

OnNoteClickedListener listener;
/* old emxample of usage
	@Override
	public void onAttach(Activity activity) {
		super.onAttach(activity);
		try {
			listener = (OnNoteClickedListener) activity;
		} catch (ClassCastException e) {
			throw new ClassCastException(activity.toString()
					+ " must implement OnNoteClickedListener");
		}
	}
*/
// new version of code
	@Override
	public void onAttach(Context context) {
		super.onAttach(context);

		Activity a;

		if (context instanceof Activity){
			a=(Activity) context;
			try {
				listener = (OnNoteClickedListener) a;
			} catch (ClassCastException e) {
				throw new ClassCastException(a.toString()
						+ " must implement OnNoteClickedListener");
			}
		}

	}