code
毛玻璃效果
UIBlurEffect *blur = [UIBlurEffect effectWithStyle:UIBlurEffectStyleLight];
UIVisualEffectView *visualView = [[UIVisualEffectView alloc] initWithEffect: blur];
visualView.frame = self.ViewNeedBlur.frame;
[self.view addSubview:visualView];
visualView.alpha = 0.8;
[visualView release];