Android Studio: Activity preview does not show title bar


i know this question has been made before here, but i have tried the solution given and i don't get the preview look in the exact style like the device does.

I am using a Samsung Galaxy S3 mini on android version 4.2.2 as my device debugging, it is completely unmodified but i don't understand why, even when i change the theme, the device still looks the same (with the changes made in the activity of course)

the code of the activity is just like any new blank activity

<RelativeLayout xmlns:android=""
    xmlns:tools="" android:layout_width="match_parent"
    android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".MainActivity">

    <TextView android:text="@string/hello_world" android:layout_width="wrap_content"
        android:layout_height="wrap_content" />


the preview looks like this
enter image description here

but the device looks like this
enter image description here

PS: I am learning android, so i might get confused with the answer

Best Solution

Had a similar problem. In my case, it was just a configuration of the design view. After I marked "Show Layout Decorations" it appeared as expected.Show Layout Decorations