android - How to align LinearLayout at the center of its parent?

Question

I've looked through numerous similar questions here at SO, but nothing helps. I have a hierarchy of different nested layouts, all have android:layout_width="fill_parent", and the inner-most layout has android:layout_width="wrap_content - I need to align it at the center (horizontally). How do I do that?

Update:: I've found the cause of the problem - if I put the inner LinearLayout into RelativeLayout with android:layout_width="fill_parent", it still wraps it's content. The TableRow, however, is really filling the screen.

<?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:orientation="vertical" >
    <FrameLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" >
        <TableLayout
            android:layout_width="fill_parent"
            android:layout_height="wrap_content" >
            <TableRow >
            <LinearLayout 
            android:orientation="horizontal"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content">
                    <TextView
                    android:layout_height="wrap_content"
                    android:layout_width="wrap_content"
                    android:text="1"
                    android:textAppearance="?android:attr/textAppearanceLarge" />

                     <TextView
                    android:layout_height="wrap_content"
                    android:layout_width="wrap_content"
                    android:text="2"
                    android:textAppearance="?android:attr/textAppearanceLarge" />
             </LinearLayout>
           </TableRow>
        </TableLayout>
    </FrameLayout>
</LinearLayout>

Answer 1

These two attributes are commonly confused:

• android:gravity sets the gravity of the content of the View it's used on.
• android:layout_gravity sets the gravity of the View or Layout relative to its parent.

So either put android:gravity="center" on the parent or android:layout_gravity="center" on the LinearLayout itself.

I have caught myself a number of times mixing them up and wondering why things weren't centering properly...