title: How do I fade in /out a rectangle or text?
body: <p>I want to achieve the effect of fade in / fade out the rect or text. I call CGContextFillRect or CGContextShowText in my UIVIew's drawRect: method. I wonder if there is a way to achieve the animation without using UIView' support(i.e. [UIView beginAnimations::]. The desired effect I want to achieve is similar to what in Microsoft's bing serach engine, like those small black squares fade in/ fade out as you move around the web page. Thanks in advance! </p>