问题
So prior to iOS 7.1 I was setting the background image in my app UINavigation Bar via UI Appearance like so.
[[UINavigationBar appearance] setBackgroundImage:[UIImage imageNamed:@"image-name"] forBarMetrics:UIBarMetricsDefault];
It was working fine and the content was getting blurred properly when behind it. Now the content is not blurred at all the navigation bar is just transparent. If I remove the image and set just the navigation bar tintColor it will blur the content correctly. Anyone have any ideas on how I can put a custom image in the NavigationBar and still have it blur the content behind it.
来源：https://stackoverflow.com/questions/22368488/ios-7-1-uinavigationbar-image