Making part of the view transparent/overlay while the rest isn't
<p>I'd like to show an overlay view similar to what you see when you perform a 'Search in Contacts app where the SearchBar is visible under the toolbar while the gray overlay covers up all of the content below.</p>

<p>For my view, I'd like to have an UITextField and button shown visible while the rest of screen is gray with the rest of the existing contents as grayed-over and no SearchBar.</p>

<p>Things I tried:</p>

<ol>
<li><p>I can have one view that encases
both UITextField and button with the
view's alpha level set to 0.5. But
this yields grayed appearance for
everything, including the
UITextField and button, which is not
what I'm trying to achieve. </p></li>
<li><p>I then tried two child views within
a parent UIView, with one subview
containing the controls while the
other one is blank. Set the parent
UIView to have 0.5 alpha -> this is
not right either.</p></li>
<li><p>Continuing with two child views
within a parent UIView, set the
parent view to have alpha of 1.0 and
then the the blank-view to have an
alpha level of 0.5, it's still not
right.</p></li>
</ol>

<p>So what's a good way to achieve this?</p>
