iOS自带的毛玻璃的效果

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];

// Override point for customization after application launch.

self.window.backgroundColor = [UIColor whiteColor];

[self.window makeKeyAndVisible];

UIScrollView *scrollView = [[UIScrollView alloc] initWithFrame:self.window.bounds];

UIVisualEffectView *view = [[UIVisualEffectView alloc] initWithEffect:[UIBlurEffect effectWithStyle:UIBlurEffectStyleDark]];

view.frame = CGRectMake(0, 0, 375, 500);

[scrollView addSubview:view];

scrollView.contentOffset = CGPointMake(0, 500);

scrollView.contentSize = CGSizeMake(375, 10000);

[self.window addSubview:scrollView];

return YES;

}