Question

1. Hai all I am new in android programming…..

   For my application I am using image button and it successfully
   installed on the device. But when I rotate the screen all the button
   position get changed… and I need all the button placed at centre
   of the screen…. And here is my code….

   <TextView
       android:id="@+id/testText"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:textColor="#FFCC99"
       android:textSize="24dp" />
   
   <ImageButton
       android:id="@+id/up"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:layout_alignParentRight="true"
       android:layout_alignParentTop="true"
       android:layout_marginRight="124dp"
       android:layout_marginTop="80dp"
       android:src="@drawable/up" />
   
   <ImageButton
       android:id="@+id/left"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:layout_alignParentRight="true"
       android:layout_alignParentTop="true"
       android:layout_below="@+id/up"
       android:layout_marginRight="200dp"
       android:layout_marginTop="150dp"
   
       android:src="@drawable/left" />
   
   <ImageButton
       android:id="@+id/right"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:layout_alignParentRight="true"
       android:layout_alignParentTop="true"
       android:layout_below="@+id/up"
       android:layout_marginRight="50dp"
       android:layout_marginTop="150dp"
       android:src="@drawable/right" />
   
   <ImageButton
       android:id="@+id/down"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:layout_below="@+id/up"
       android:layout_alignParentRight="true"
       android:layout_marginRight="124dp"
       android:layout_marginTop="80dp"
       android:src="@drawable/down" />
   

   Please help…………

Answer 1

Set android:gravity to center.
The following layout will do for you:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:gravity="center"
              android:orientation="horizontal" >

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Cool Button" />

</LinearLayout>

There are other ways to do it.
1. Using relative layout
2. Using 2 layouts : 1 one for portrait and and 1 for landscape.