How do I programmatically provide a glossy look to UIButtons?

Question

I would like to add 3D or glossy look to some iPhone UIButtons, but do so without the use of PNGs or stretchable images. I have a lot of buttons of varying shapes and sizes

Answer 1

UIButton *button1                 =   [[UIButton alloc] initWithFrame:CGRectMake(10, 10, 200, 40)];
button1.backgroundColor           =   [UIColor blackColor];

CAGradientLayer *gradient = [CAGradientLayer layer];
gradient.frame = button1.bounds;
gradient.colors = [NSArray arrayWithObjects: (id)[[UIColor grayColor] CGColor],(id)[[UIColor blackColor] CGColor], nil];
[button1.layer insertSublayer:gradient atIndex:0];