Just a quick note to anyone like me experimenting with Android development. Take this XML snippet:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="@string/hello"
    />
<Button
	android:id="@+id/btn01"
        android:text="@string/goButton"
    />
</LinearLayout>

I hit compile, it built fine and went to the simulator, but the app crashed right when it ran. Apparently, LinearLayout requires the layout_height and layout_width to be defined, as such:

<Button
	android:id="@+id/btn01"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="@string/goButton"
    />

I’ll continue to post these idiot moments as I find them…