Center a button in a Linear layout

Question

I am using a linear layout to display a pretty light initial screen. It has 1 button that is supposed to centre in the screen both horizontally and vertically. However no matter what I try to do the button will top align centre. I have included the XML below, can some one point me in the right direction?

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"     android:orientation="vertical"     android:layout_width="fill_parent"     android:layout_height="fill_parent">      <ImageButton android:id="@+id/btnFindMe"          android:layout_width="wrap_content"          android:layout_height="wrap_content"         android:layout_gravity="center_vertical|center_horizontal"         android:background="@drawable/findme"></ImageButton>  </LinearLayout> 

Answer 1

Center using a LinearLayout:

<LinearLayout     android:id="@+id/LinearLayout1"     android:layout_width="match_parent"     android:layout_height="match_parent"     android:gravity="center"     android:orientation="vertical" >      <ImageButton         android:id="@+id/btnFindMe"         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:background="@drawable/findme" /> </LinearLayout> 

Answer 2

If you want to center an item in the middle of the screen don't use a LinearLayout as these are meant for displaying a number of items in a row.

Use a RelativeLayout instead.

So replace:

android:layout_gravity="center_vertical|center_horizontal" 

for the relevant RelativeLayout option:

android:layout_centerInParent="true" 

So your layout file will look like this:

<?xml version="1.0" encoding="utf-8"?> <RelativeLayout android:id="@+id/RelativeLayout01"      android:layout_width="fill_parent"      android:layout_height="fill_parent"     xmlns:android="http://schemas.android.com/apk/res/android">      <ImageButton android:id="@+id/btnFindMe"          android:layout_width="wrap_content"          android:layout_height="wrap_content"         android:layout_centerInParent="true"         android:background="@drawable/findme"></ImageButton>  </RelativeLayout>