No title bar Android application without titlebar style Theme NoTitleBar Android example

<manifest xmlns:android="//schemas.android.com/apk/res/android"
    package="com.myexample.without_titlebar">
    <application android:label="My app">
      <activity android:name="NoTitleBar"
        android:theme="@android:style/Theme.NoTitleBar"
        android:screenOrientation="portrait"
        android:configChanges="keyboardHidden|orientation">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
</manifest>