[android] How to show shadow around the linearlayout in Android?

For lollipop and above you can use elevation.

For older versions:

Here is a lazy hack from: http://odedhb.blogspot.com/2013/05/android-layout-shadow-without-9-patch.html

(toast_frame does not work on KitKat, shadow was removed from toasts)

just use:

android:background="@android:drawable/toast_frame"

or:

android:background="@android:drawable/dialog_frame"

as a background

examples:

<TextView
        android:layout_width="fill_parent"
        android:text="I am a simple textview with a shadow"
        android:layout_height="wrap_content"
        android:textSize="18sp"
        android:padding="16dp"
        android:textColor="#fff"
        android:background="@android:drawable/toast_frame"
        />

and with different bg color:

<LinearLayout
        android:layout_height="64dp"
        android:layout_width="fill_parent"
        android:gravity="center"
        android:background="@android:drawable/toast_frame"
        android:padding="4dp"
        >
    <Button
            android:layout_width="fill_parent"
            android:layout_height="fill_parent"
            android:text="Button shadow"
            android:background="#33b5e5"
            android:textSize="24sp"
            android:textStyle="bold"
            android:textColor="#fff"
            android:layout_gravity="center|bottom"
            />

</LinearLayout>