RelativeLayout center vertical
I have edited your layout. Check this code now.
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"android:layout_width="fill_parent"android:layout_height="wrap_content"android:background="#33B5E5"android:padding="5dp" ><ImageView android:id="@+id/icon" android:layout_width="50dp" android:layout_height="50dp" android:layout_alignParentLeft="true" android:layout_centerInParent="true" android:background="@android:drawable/ic_lock_lock" /><TextView android:id="@+id/func_text" android:layout_width="wrap_content" android:layout_height="100dp" android:layout_gravity="center_vertical" android:layout_toRightOf="@+id/icon" android:gravity="center" android:padding="5dp" android:text="This is my test string............" android:textColor="#FFFFFF" /><ImageView android:layout_width="50dp" android:layout_height="50dp" android:layout_alignParentRight="true" android:layout_centerInParent="true" android:layout_gravity="center_vertical" android:src="@android:drawable/ic_media_next" /></RelativeLayout>
If View's height/width = wrap_content
use:
android:layout_centerHorizontal="true"android:layout_centerVertical="true"
If View's height/width = match_parent
use:
android:gravity="center_vertical|center_horizontal"