iboss-mini-android-bjmnls/res/layout/item.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:gravity="center"
    tools:context=".MainActivity" >
 <ImageView 
     android:id="@+id/iv"
     android:layout_gravity="center"
     android:layout_width="200dp"
     android:layout_height="200dp"
     />
</LinearLayout>