How to correctly set alpha of UIView? [iOS]

问题

I have UIView with lots of subviews (UILabel, UITextView, etc.).

If a set alpha 0.6 to main view all the subviews takes this alpha.

How to set alpha separately of main view?

回答1:

 [view setBackgroundColor:[[UIColor clearColor] colorWithAlphaComponent:0.5]];

 //try this.. dont try to set alpha of UIView and also your subviews will not affect

回答2:

myView.layer.shouldRasterize = YES

This will make it use group opacity and everything should composite as you'd expect.

来源：https://stackoverflow.com/questions/17079160/how-to-correctly-set-alpha-of-uiview-ios