Set layout weight, gravity and background

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="#ffEEee"
    android:gravity="center"
    android:orientation="horizontal"
    android:weightSum="1" >

    <Button
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="0.5"
        android:text="Click Me" />

</LinearLayout>

import android.app.Activity;
import android.os.Bundle;
// www  .j av  a2  s.co m
public class MainActivity extends Activity {

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
  }
}