iOS 5 UINavigationBar removing subviews ( image su

问题:

In my application that works fine on iOS 4 navigationBar dissappeared starting iOS 5. Here is what I figured caused issue: I was removing subviews in RootViewController viewWillAppear method:

for(UIView* view in self.navigationController.navigationBar.subviews)
    {
        if ([view isKindOfClass:[UILabel class]]) 
        {
            [view removeFromSuperview];
        }
        if([view isKindOfClass:[UIImageView class]])
        {
            [view removeFromSuperview];
        }
    }

I was doing this because Second view controller that I push onto navigation controller add's image and label to navigation bar which I have to remove when view is popped. In iOS 5 the above code removes navigationBar. How to fix this or right way of doing it to support both iOS4 and iOS 5 ?

回答1:

setTag for those image and uilabel then removing it from code above did the trick.

for(UIView* view in self.navigationController.navigationBar.subviews)
{
   if(view.tag == 9 || view.tag == 99)
   {
      [view removeFromSuperview];
   }
}

回答2:

You could make your added views subclasses of their respective UIKit classes and check against those specific subclasses. Really though, to have the clearest, most readable code, you should subclass the navigation controller and navigation bar to allow for a custom image and label to be drawn such that you could simply set the background image and foreground label to nil. It would take a little time to put together, but the end result would be much more extendable.