iOS 8之后新添加了UIBlurEffect 类和 UIVisualEffectView 类来实现毛玻璃磨砂特效。
UIBlurEffect *blur = [UIBlurEffect effectWithStyle:UIBlurEffectStyleLight];
UIVisualEffectView *effectview = [[UIVisualEffectView alloc] initWithEffect:blur];
effectview.frame = self.bounds;
[self addSubview:effectview];
毛玻璃特效类型:
UIBlurEffectStyleExtraLight
UIBlurEffectStyleLight
UIBlurEffectStyleDark