How can I dim the view in an iPhone application?

Question

I've seen a lot of iPhone apps that will dim the screen with an activity indicator when it's updating or downloading something to let the user know it's busy. I know how to do the activity indicator but how do I go about doing the dimming? Please post example code if you can.

Answer 1

They don't actually dim it, Apple won't allow apps to adjust the screen brightness. They just put a black, semitransparent image over the screen, which has a similar effect.

Edit:

Jailbroken applications can adjust the screen brightness, and there is an API to do it, however Apple will not approve of any application that changes the screen brightness.

Answer 2

Ok, the way I did this was too create another view and set the opacity very low. Then I add this view as a subview.